The temperatures in Maine have been below zero for more than a week. This is some of the strangest weather we've had since the blizzard of 98, 20 years ago tomorrow. And days like today remind me why we build the way we do. As you watch the news you see people running out of heating fuels and the threat of freezing is a real concern. But people like the Miller's at Live Solar Maine are watching the snow swirl around their house in today's blizzard while 1 or 2 sticks of wood in the wood stove will keep the house above 80 degrees even if they lose power. The solar panels on the roof will keep them from losing power for long periods, and the threat of freezing isn't a concern. They can sit and watch the snow swirl around the house as if they are inside of a snow globe.
It takes a little bit longer to build super insulated structure. It takes a little bit more thought to put it all together. But winter days spent inside a home with no drafts, temperatures above 80, and the security of keeping your family warm on these cold cold days makes it well worth it. Not everything in a zero energy house costs money. The simple act of facing the house south can have a huge impact on the way it performs. Spending the time to seal all gaps, cracks, seams, and holes in the envelop is very cheap with an extremely quick return. And air sealing is something pretty much any homeowner can do. The best thing you can do when installing windows is seal around them after they are installed. Instead of stuffing fiberglass next to the windows, use a low expanding spray foam and make sure they are sealed in well. This is where most people see the savings on windows. Put in the best windows you can afford while building, and then seal them. The performance of a window will never equal the performance of an insulated wall. The Live Solar Maine homes have double pane, double hung windows. Although the comfort level of a triple pane window can be really wonderful, if it doesn't fit in your budget it doesn't keep you from building a zero energy ready home.
So as you consider building a new home, think about the benefits of building a better home. Take into consideration the costs of building better and the costs of choosing not to on these winter days. It isn't just about the money, it's comfort, durability, and the safety of your family.
Wishing you all happiness in 2018 and we hope you are enjoying your coffee inside your warm snow globe as the blizzard snow and wind whips around outside.
Check Out Mottram Architecture's Live Solar Maine Project in Maine Home + Design
Click the link (solar1 maine mag) to see a copy of the write up in Maine Home + Design MagazineWe couldn't be more thrilled with seeing the first house represented in the Architecture Issue!What a great way to end 2017! Wishing you all the very merriest of holidays!Peace and love to you and yours from all of us here at Mottram Architecture!
Building + Science: Moisture Movement In Your Home
I belong to a group forum filled with other architects. We bounce ideas, products, and share knowledge. One of the questions posted this week had to do with vapor barriers and insulation systems. Then, a few days later, I met up with another energy professional and we had a discussion about vapor barriers and wall systems. It made me think: Do owners, architects and builders know about moisture in their homes?It is important to understand moisture because trapped moisture can lead to mold, rot, and structural issues. All parts of your home "house as a system" must work together to keep moisture from causing damage and health hazards to the occupants, not to mention the fact that wet insulation just does not work. So let's talk about science.
First, where does the moisture come from? It has became clear after talking to some builders, owners, and architects, that many people don't know where the moisture comes from to begin with.Construction materials, up to 40 quarts of water a day for the first year after new construction. You may have heard that your house will dry out for a year or two after construction. But most people don't even seem to know that.Damp basements and crawl spaces without vapor barriers, 25 quarts a day. This one really irks me! Basements and crawl spaces are an integral part of a home. Not only are they the sturdy foundation upon which our house stands, but they can also be the leading causes of moisture and energy loss.Humidifyers: 20 quarts a day. In cold climates where the air leaking into the home has very little moisture in the winter time, many people use humidifiers. This often exasperates health issues related to moisture trapped in homes that are closed up tight for the winter.Drying firewood indoors: 16 quarts a day. Two things to mention here, 1. firewood drying out in your basement lets that moisture go somewhere, so now you need to control another moisture source. But firewood can often come with bugs, and what are most houses made of? Wood? I think you're getting the idea. So store it outside, under cover, at least a foot or two away from the structure of your home.Unvented clothes dryers: 13 quarts a day. Plain and simple, this is a health hazard. People tell me they do this to recapture the heat that the dryer is producing. What they fail to consider is the moisture causes much more damage then the small amount of heat that is reclaimed and the heated byproducts of laundry detergents and softness are toxic.Breathing: (Family of 4): 4.7 quarts of water a day. Breath on your hands. They got a little damp right? Right. So every time you exhale, out comes water vapor. So where should we provide fresh air in a home? The bedroom, because most people work outside the home, they spend the majority of their time at home (8-hours) sleeping in a room with the door closed and the heat turned down. Since the room is cool, it can't hold as much water and condensation begins to show up on the cold surfaces.Cooking, dishwashing, house plants 0.5-1 quart a day. Plants put more than 90% of the water you supply them back into the air. I'm not going to tell you not to have house plants, they have other benefits, but maybe we shouldn't live in a greenhouse and in the winter time, pull the plants away from the windows where they deposit their moisture as condensation onto the cold surfaces.Now that we have an idea of where this water might be coming from, how is it moving?If a builder and/or architect understand the way water vapor moves and knows what climate zone the house is located, then we can come up with a solution on how to control the moisture. There are ways to control vapor diffusion that are ineffective at controlling air-transported moisture and the same is true in reverse. An effectively built home is designed to control both vapor diffusion and air transportation. And it's important to know what climate zone you live in to understand where that moisture is coming from. (Outside in hot/wet and Inside in Cold).Vapor diffusion is the how moisture moves through a material because of a difference in pressure or a difference in temperature. Vapor diffusion is not air movement. Vapor diffusion is water vapor moving through a material from a high pressure to a low pressure, or a warm side of a wall to a cool side of the wall. Diffusion through materials is a slower then vapor moving through air transportation. Most common building materials slow moisture diffusion, but do not stop it completely. For this reason, we often use vapor barriers with low perm ratings to help slow down diffusion. For example, 6-mil poly under a concrete slab to prevent ground moisture from diffusing quickly through the concrete slab.Air Transportation: Air can move and flow quickly and in large volumes. Air transportation accounts for more than 98% of all water vapor movement in building cavities. Air naturally moves from a high-pressure area to a lower one by the easiest path possible. Significantly more water vapor travels through a wall by air leakage than by diffusion. This is also part of the reason why we hate fiberglass insulation. Different insulation systems will reduce airflow and fiberglass is not one of them. At the same time, spray foams and rigid insulation have lower permeability and can inadvertently create a vapor barrier in a wall system where you didn't intend for it to be.Now we know where the moisture might be coming from and how it's moving about in our home. But maybe we still don't understand why it's a problem. So let's take a minute and talk about Relative Humidity. I know, I'm using all those science words that you thought you left behind in high school. But it's important in our homes to know at what temperature and moisture concentration water vapor begins to condense. This is called the "dew point." As air warms, it can hold more water vapor. As the air cools, it can no longer hold as much water and it condenses on the first cold surface it encounters. If this surface is within an exterior wall cavity, wet building materials will be the result. And we do NOT want that. Where you are more likely to have seen it is on a window in the winter time. As the moist/warm interior air hits the cold window surface it deposits the moisture it can no longer hold on the window and you see beads of condensation. This same thing could be happening in your wall system and you don't even know it. That's why it's important to understand how that moisture is getting out and that we are not creating a surface within our walls for it to condense and create an issue. And adding more insulation isn't always the best solution. In some cases it can cure a problem, or it might cause one. When a wall is insulated, the temperature inside that wall is changed. A surface inside that wall, such as concrete blocks that were insulated on the interior, can become much colder in the wintertime than it was before the wall was insulated. This cold surface could be the place where moisture traveling through wall condenses and causes trouble like freeze thaw.
So what should you do? First, understand that a vapor barrier, air barrier, and weather resistive barrier are not the same thing. The vapor barrier debate has been an on-going energy and building conversation for years. But whether you are pro vapor barrier or not, what you need to know is that you WILL have water in your home and in your wall system and you need to know how it's getting out.In an ideal world we keep what's outside, outside. Install a weather resistive barrier to prevent the water from getting in from the outside. Water coming into the house, even if it is a small leak, must be controlled. This is where we talk about weather resistant barriers which should be vapor open to let moisture in the wall out, but they should stop weather related moisture form getting in. Proper flashing at openings, rain screens, gutters and other moisture control systems on the exterior of the building should be used to control where exterior moisture goes in relation to the house. All of these things are critical and important.Air Seal. It is important to that the air leakage pathways between the living spaces of the house and other parts of the building are stopped. Air leakage into a wall or the attic can carry significant amounts of moisture. If there is air leaking around electrical, plumbing, and ventilation penetrations, moisture will be carried along with it. Ductwork needs to be sealed and insulated, especially if the ducts pass through an unconditioned crawlspaces or basement or unheated attics. Air sealing is critical.Then we design a wall system to provide a path for moisture to escape. A wall system should be designed to allow moisture to escape from a wall cavity to the exterior to dry during the winter. Or a wall can dry to the indoors by avoiding the use of vinyl wall coverings or low-perm paint. Your WRB is letting the moisture out in a one way vapor open scenario, your thermal and air barriers are in line and fully touching, and your vapor barrier, if you have one, is on the warm side and not in line with the dew point of the wall.Ventilate. The home needs to be ventilated. Your WILL generate moisture inside your home. Where does it come from? Cooking, shower, laundry, houseplants and even breathing, you saw the list above. This water vapor can add 5 to 15 gallons of water per day to the air inside your home. The tighter we build our homes to prevent air transported moisture migration or heat loss, the more conscientious we need to be about ventilation on the inside to provide healthy indoor air quality and reduce durability issues related to moisture trapped within the home. However, the use of mechanical ventilation can create a pressure difference and drive both air infiltration and vapor diffusion. So it's very important how you ventilate and that you don't over ventilate.
In conclusion, moisture is a major factor in building. We need to know where it's coming from and how it's moving through the spaces. It's not as simple as it seems. As new products come on to the market and the ways we build change, it's very critical that we understand how to prevent health, safety, and durability issues.
Mottram Architecture - In the Community
It's been a very busy year for us here at Mottram Architecture, but today I want to take a moment and highlight a project that we are really proud of.If you follow us, you may have already seen some posts we have shared about this project which kicked off in December of 2016. With the help of more than 15 organizations, 30 people and 22 students, this home became a reality for two very deserving people on July 1st 2017. With a lot of love and a few back breaking hours (mostly shoveling) what was a prototype we developed for home replacement with Western Maine Community Action became the first in what we hope is a series of home replacements that might happen across the state of Maine.We firmly believe that everyone should have access to a great place to live. And in Maine, that means having a warm, dry, and healthy home for what we consider "9 months of winter". Okay, I exaggerate, but with a lot of thought we were able to accomplish "less square footage with way more room" The students at Foster Tech were out building this home in the 20 degree weather all through the winter. They shoveled more snow here at the job site then they probably did at their own homes! Shovel the ground, shovel the roof!When I was in high school, my grandfather was a contractor, and together we participated in a number of community projects through our church where we helped to rehab homes. So when Bill, at Western Maine Community Action, asked if I would help them develop a prototype for a home replacement program, I jumped at the opportunity. It meant a lot to me that they wanted to provide the most efficient housing that they could and when I found out that they were partnering with the local trade high school I was even more excited to participate. The ways we build are constantly changing and it's so rewarding to see these students graduate with construction skills and additional knowledge on how to build better in cold climates.If you'd like to read more about this project and the people who were involved, check out the following articles that have been written (and maybe a few I missed) since we started construction in January.Sun Journal August 2017In July this project was shared nationally through the Community Action eNews:It all started two years ago when Pam and Joe, weary of putting out pans to catch the drips from the leaky roof and patching in new flooring where the soggy, particle-board underlayment had finally given way, showed up at Western Maine Community Action to ask about a low-interest loan to replace the roof.Read about how something wonderful happened, all because a community - in the broadest sense of the word - saw fit to help an aging couple stay put. It's a model Bill Crandall, who manages the Housing and Energy Program for Western Maine Community Action hopes to replicate all over Maine.Along with this article written by the Press Herald July 23rd 2017In March, the Maine Community Foundation shared the following article:A HousewarmingAnd below are the three articles written after the ground breaking in DecemberThe Daily BulldogThe Sun JournalThe Franklin JournalAnd if that isn't enough information, feel free to join us at the Maine Affordable Housing Conference on September 22nd, where WMCA, Foster Tech, and Mottram Architecture will be presenting more on this project.Maine Affordable Housing Conference September 22, 2017
Do Homebuyers Want "Energy Upgrade" Packages?
We were recently featured in the Insulation Institute's Quarterly Newsletter. Below is the story by Stacy Fitzgerald-Redd. For more information on the Insulation Institute, click HEREAre builders missing the mark by not offering upgrade options for HERS-Scored homes?Homebuyers like choices. Builders, ever eager to meet the desires of their buyers, typically offer a dizzying array of choices in products, finishes and designs to suit a wide variety of styles. Yet seemingly few builders offer consumers a choice in homes at varying energy efficiency targets. Is this a missed opportunity for builders in meeting the growing energy efficiency desires of buyers -- an increasing number of whom self-identify as sustainable consumers? Perhaps. Research from McGraw Hill Construction shows that 73 percent of home buyers are willing to pay more upfront for green home features, like energy efficiency. How much more? According to the Green Building Advisor, the most common estimates are 1 to 3 percent. In that HERS scores are the equivalent of a miles-per-gallon ranking for home performance – the lower the score the better -- a lower HERS score means reduced home energy costs for homeowners. Homebuyers might be willing to pay more if they thought they’d get more, in terms of energy savings. Take this as an example:
- HERS score of 65. This is often about level offered by builders as energy efficient. This could be the baseline or “good” efficiency package.
- HERS score of 40. A home at this level would likely be net zero energy ready, meaning it is super-efficient and can become net zero by integrating solar or other onsite renewables. This would be the “better” efficiency package.
- HERS score of 0. This is a net zero home. This would clearly be the “best” package a homebuyer could opt for.
Homebuyers are familiar with the package approach, though it remains to be seen how much they’d be willing to pay for HERS scores at different levels. What is indisputable is that the integration of good design and construction plays a major role in determining energy performance, something architects are increasingly advocating.Evaluating the Good, Better, Best ApproachEmily Mottram is the owner of Mottram Architecture, a full service architecture firm specializing in energy efficient design and Net Zero construction in New York, Pennsylvania and Maine. Her seven-year-old company also offers energy consulting, energy audits, HERS ratings and consultation on building envelope design. Mottram’s clients are typically driven by the dual desire for sustainability and energy efficiency but the option of offering a “good, better or best” performing home – reaching a specific performance target or HERS score at an incremental price increase that the buyer would be willing to bear, is in her opinion, a largely untested concept.“I’ve recently been discussing the idea of a ‘pretty good home’ with some building industry colleagues and there’s a definite awareness that a HERS 60 home, for example, could be an acceptable target for one buyer, while only a Net Zero home would work for another,” Mottram said. Offering homes in specific HERS target ranges could hold appeal for a certain segment of homebuyers willing to pay more upfront for more comfortable homes with lower utility costs. This could be a win-win for customers and builders who can offer more targeted options to meet customer needs. Regardless of the target, Mottram says that architects and builders can do a number of things that will increase home efficiency and help lower overall HERS scores and many are inexpensive or have relatively low incremental costs.Integrating Good Design, Construction Practices“One trick that literally costs nothing is the orientation of the house,” she said. “Using the sun for its heating potential and reducing North windows will ultimately save consumers money on energy costs.” Mottram notes that increasing the focus on the thermal envelope – particularly installing good air barriers, taping and sealing in the right locations, can dramatically improve the energy performance of a home. In addition, increased insulation -- R21-40 walls -- offers significantly higher energy performance. “Also, reducing the framing and having a tightly sealed envelope allows for more insulation and pays for itself in no time. “Simply maximizing the placement of windows -- these are all things that can boost energy efficiency,” she added.“By focusing on good design and construction practices, you can get a better performing home for reasonable incremental cost, but the design has to focus on proper construction and air sealing, which is why building science education, is so important,” she said, adding that regardless of the energy performance target, builders must increase their knowledge of building science and its impact on energy performance. “It does require a little more though from the builder to use less framing and increase insulation values. It takes more skill to follow through with contractors on the air sealing, air barriers and doing it all in the right locations, but this is ultimately how you maximize home energy performance, regardless of what the HERS score target might be.”Where Best Practices and Energy Upgrades IntersectBuilders will need to determine consumer willingness to pay for energy efficiency at various cost levels to determine if an “energy upgrade” approach makes sense. However, from a practical standpoint, builders would need some commonality, across upgrade options, to make the building process for homes of different efficiency levels feasible. The best way to do that is to have some energy efficient best practices that are undertaken on all builds, for example advanced framing, raised heel trusses, approaches to air barriers and sealing, things that impact the overall design and build process. Other items, like water heating and lighting efficiency, are more easily adjusted with less impact on the build process or other building systems. This would also help drive down the incremental costs for efficient building, improving the consumer return on investment. It is hard to say if energy upgrade packages are part of the future of housing, but if they are, they will be enabled by a broader, baseline level of energy efficient building practices.
In The Community with Mottram Architecture
I'm pleased to report that the Community Home Replacement Program's first project has started off extremely well given our late start into the building season!It was our pleasure to participate in this project and kick it off with a "Ground Breaking" ceremony held last week on December 7, 2016. There is so much local community support for this project all the way from residents though great companies like Hammond Lumber and Matthew's Brothers!But most of all, I'm thrilled that the kids at Foster Tech will be involved in this project. They will have hands on experience with green building technologies that will help them make better homes for the rest of their building careers!Absolutely everyone should have access to better homes, and we couldn't be more proud a part of this project!Below are the three known articles links if you're interested in learning more about the project:http://www.dailybulldog.com/db/features/wmca-led-collaboration-to-build-a-house/http://www.sunjournal.com/news/franklin/2016/12/12/new-chesterville-home-be-built-through-collaborative-effort/2044737http://thefranklinjournal.com/home-leisure-show-images/Since last Wednesday - the home is growing from the ground up and they now have a poured frost wall with the likelihood of the students beginning their work early next week.Wishing you all a great holiday season!!!With Love, Emily Mottram
Passive House with Mottram Architecture
Sorry for the lack of updated content over the last couple of weeks! I decided that it was finally time to take the Passive House Course. I've been teaching sustainable design for several years on top of practicing it here at Mottram Architecture. Although I knew the principles of passive house, and I have done blower door tests on a few local passive house homes, I had yet to take the certification course myself. Like all great programs, I needed continuing education credits for my HERS certification, so I decided to take the plunge, hence my long absence. The Certified Passive House Designer course "the German version" was only offered through New York Passive House Academy in NYC! It's a two week course that ends with a 3 hour exam. So I spent a considerable amount of time traveling back and forth between NYC and my office over the course of May. So thank you for your patience and here's some of what I learned.What passive house means to me is a lot of calculations, scientific data, cool but complicated construction details, and lots of integration to make sure all the parts work together. But what should passive house mean to you? Comfortable, durable, and healthy homes. Passive House, in an ideal scenario, would be able to heat a home with a small amount of electric heat added to the ventilation system. This may be possible in Germany, but unfortunately it's not quite possible here in New England. So some adjustments are made for longer, harsher winters, and higher humidity summers. I could list all the program requirements, but I think instead I'll give you the reasons why this is the direction we feel the building community should move.Targeting 70-80% reduction in energy demand in homes is great. It means building them tighter, smarter, with better insulation and fewer moving parts. We are trying to simplify the usability of the systems. I don't mean building smaller, in fact, in the passive house program, it's actually harder to achieve the standards with smaller homes. What I mean by simplify is the elimination of large and complicated heating systems. A better air quality system that doesn't account for fresh air being drawn in from any crack or crevice in the building envelop. And most importantly, understanding human comfort and keeping the system balanced to those comfort levels.Everyone can understand the value of a dollar + inflation, but the added benefit to reaching passive house targets is comfort. I recently sat down with someone who mentioned that a few years ago they built a new home. After moving in they discovered, that although it was beautiful, it had all the right finishes, it was terrible to live in. They felt somewhat jaded that they spent all this money to build a wonderful home and had to deal with drafty construction and discomfort in their home. Building a home will likely be the most expensive personal purchase you make in your lifetime. Getting it right the first time can be hard.
- Thick Insulation
- Air-tightness
- Prevention of moisture migration
- Optimize the window areas and sizes
- A reliable, steady supply of fresh air
Thick Insulation: I can't stress enough that when you build a home you should not skimp on the insulation. This is the most difficult thing to change after a home is finished. It also seems to be the first thing on the chopping block when budgets get tight. Resist the urge to change your insulation package. Not all insulation is created equal and changing the insulation package could be the difference between you loving your home and not being able to stand it. We have a range of temperature in which we are comfortable. When insulation is poorly installed, is used in the wrong application, or gets cut, the ability to keep the wall temperature warm in the winter and cool in the summer suffers. You can understand that radiators radiate heat into the space. Well the same is true in the opposite. If the wall is cold, you will radiate heat to the wall. Losing body heat makes you feel cooler and can often be confused with drafts. Our thermal comfort is directly affected by the surface temperatures around us. So poor insulation, or not enough insulation, causes us to feel uncomfortable in our homes. And on the plus side, the more insulation you have to reduce heat transfer, the less money you'll spend to keep your home warm.Air tightness: Houses do not need to breath. I repeat, houses do not need to breath. It is incredibly important to make sure that air moves through your home where you want and when you want. It's critically important to control moisture inside the house, along with other toxins that are often found in our building materials, the products we use, and the smells from what we cook. Outdoor air is necessary for healthy living, but people need to breath, not buildings. Drawing air though the building construction can lead to other more serious problems like the collection of moisture within walls. Air infiltration is also an extreme source of heat loss. Every time air leave your home, it's replaced by air from somewhere else (outside, the attic, walls, basement etc). In the wintertime, you have to re-heat every cubic volume of air that escapes. We seem to forget that the draft isn't just letting cold air in, it's letting warm air out, and that's costing you money.Prevention of moisture migration: As you can see, air tightness and moisture migration are tied very closely together. We will always have moisture within our homes. When we breath we respire moisture. When we cook we put moisture in the air. When we supply fresh air it comes with humidity from outside. Controlling the flow of that moisture, and exhausting it to the exterior, is important. When we have cold surfaces, the moisture in the air will deposit on the surface and can grow mold. When we have leaky buildings, the moisture in the air can be pushed into the wall cavities and create condensation and rot. When hot air rises and is able to escape into our attics it can condense on the inside and make us think we have roof leaks. When a hole is drilled for a chimney and not air sealed it can "rain" indoors. Controlling the moisture is so critically important.Optimum Windows: We no longer want to live like cavemen. We want bright airy beautiful windows that take advantage of the view, let in the sunlight for light and warmth, and allow us to feel like we are outdoors without the harsh conditions. But when it comes to windows, the public is sadly mis-informed and the US is lagging behind it's German friends. It's actually cheaper to buy a triple pane window in Germany than it is to buy a double pane window. They have understood that an additional layer of glass keeps the surface temperature high enough to reduce thermal discomfort and condensation. When achieving the passive house certification, it's still necessary to buy windows from Europe to meet the requirements. Tested for air infiltration (drafts), thermal bridging (component parts), and overall U-value, we are still waiting for US Manufacturers to meet all these standards. I'm not saying it's not possible, I'm simply stating that no US manufacturers are currently approved by the standard to meet all the requirements. However, when I say the public is misinformed I mean that doing a window replacement will not save you money in your home. It's not as simple as new windows, the true value and savings is in how they are installed. Passive house takes great care to monitor both the window itself and how it is installed. Most replacement window projects that see vast savings come from air sealing during the installation, not the window itself. The major difference in triple pane windows is the thermal comfort and reduction of condensation which cannot be attributed to performance, but can be counted in comfort.Fresh Air: I mentioned previously that houses do not need to breath, but people do, and this is critically important. When we first started tightening our homes to improve efficiency, we didn't know that fresh air was necessary. We created what many call "sick building syndrome". We had mold and contamination issues that gave building science a bad name. We have since discovered that there is a ratio of fresh air needed, per person, to have healthy indoor air. If you took note above, air isn't exactly "fresh" if you don't control where it comes from. Having leaky drafty buildings means high heat loss, but it also means the "fresh air" for the home may come from your wet basement, your dusty attic (and let's all admit we've seen a critter or two up there), or through dried out dirty cracks in our building envelope. With passive house, not only are you supplying fresh air from an intake that isn't positioned in the attic or next to the dumpster, but you're supplying it where you need it most. Most people work outside of the home, so when we are home we spend a majority of that time sleeping in our bedrooms. By providing fresh air to the bedrooms we can improve the quality of the space we live. We are also pre-heating the air so it is not introduced to the space at outdoor temperature. (Negative 15 in Maine in February) and capturing energy by not having to heat the incoming air. The ventilation system also extracts air from places that are high in moisture (kitchens & baths). In an ideal scenario, this will be the one piece of equipment you need in your home, and it should be simple to use and operate.If you're interested in the more detailed scientific data behind passive house, don't hesitate to reach out. If you're a passive house consultant, we'd love to connect with you! Here at MArch, we think the constant pursuit and sharing of knowledge is beneficial to everyone! We'd love to hear from you!
Comfortable, Happy, Healthy Homes: How To Get To Net-Zero
Cost-effective zero energy homes start with the design. Don't skimp on design if you want the performance without excessive cost. Nobody, I mean really, nobody, wants to live in a house that they spent hard-earned money building (or buying) and then shell out more money every year just to sit around in three sweatshirts because you refuse to turn the heat up. We want to sit in the warm sunshine, maybe drinking our coffee, reading the newspaper, and not worry about the dollars that are flying out the door. Did your mom ever yell "Do you live in a barn, close the door". Well we don't live in barns, and we don't want to live in drafty uncomfortable spaces either. We want to live in warm, cozy, happy, healthy homes. So how do we get there?One of the ways we do that is through energy modeling. During the design phase we always run our projects, especially net-zero bound projects, through our energy modeling software. I won't get into the weeds on all the data that goes into an energy model, but I will tell you what we use it for. Doing the energy modeling during the design phase allows us to evaluate different building techniques, heating systems, and performance data to come up with the best solution for your individual needs. The industry calls this technique, cost offsetting. If we can add more insulation to your walls, we can reduce the need for a central heating system. If we can reduce or eliminate the central heating system, the costs of construction go down. We like to use the term "house as a system" which means your house is a series of inter-related parts. When you change one part, if affects others. By using energy modeling software we can compare different construction techniques to come up with the best combination of different parts.Another cost offsetting technique that we love to use is orientation! So simple, and absolutely free. If we look at history, the ancient Romans knew which direction to face their buildings and how to use mass to absorb heat. Use the sun for passive solar gain, brilliant! Modern day building practices have almost completely ignored this one simple solution. In addition to orienting the house the right direction (south) we also take time to place windows to take advantage of the view while at the same time, eliminating windows where we don't need them. If we can cut down windows on the north side of the house, the performance of the home skyrocket. That doesn't mean we live with dark spaces. One of my favorite solutions to fewer windows is interior windows. A great way to add character and style to a house is to pick an old window and install it in an interior wall between a room with lots of natural light and one with low or no daylight. This is especially effective for lighting interior stairways without adding skylights to the roof. If you've been following my blog or know me in person, you've probably heard me say "windows never pay for themselves". So why pay a lot of money for a poor performing building material instead of spending time during the design process to pick and place the right window in the right location. Should you order triple pane windows from Poland? Maybe? Should you take the time to maximize windows in the best locations and eliminate them where not needed? Absolutely! Can you hit Net-Zero with builder grade double pane windows from a major window manufacturer? Yup! Are you starting to see the forest through the trees? Getting to 0 from 100 is all about design.To get all the way down to 0 though, you have to produce as much energy on your site as you use. We can super insulate the building, eliminate thermal bridging, reduce air infiltration, orient the house the correct way, but what we can't do is completely eliminate energy use. So we need to produce energy on site to offset the usage. If we oriented the house the correct direction, adding solar panels is usually the quickest and easiest on site power generator available. Some people, depending on location, may be able to harness wind power or hydro, but the average homeowner should be able to take advantage of PV. With the government subsidizing solar installations it's getting more cost-effective to add your own power generation to your home. Between off the grid battery banks and grid-tied net metering, there is a way to harness the power of the sun to produce electricity.If you're reading this article and thinking "but all these super efficient houses are ugly" you should go back and read one of my previous blog posts on selecting the right architect. We all have different taste, and if you select the right architect for your project it can be cost-effective, efficient, and beautiful. And here you thought building a house was simple, little did you know it's one of those giant jigsaw puzzles, that until you get all the parts lined up just right, you just have a pile of building materials that may or may not turn into a happy healthy home.There are lots of different ways to get to zero energy. So like I said at the very beginning, spend time during the design to get all the details right. You can simply monitor your actual energy usage for a year and prove that you made more energy then you used. Or you can take advantage of one of the certification programs out there for meeting the zero energy threshold. Here are a few:ProgramsLiving Future Institute: Zero Energy Building CertificationDepartment of Energy: Zero Energy Ready HomeNYSERDA Net Zero Energy Homes Low Rise New Construction ProgramLEED Zero Net Energy HomesIf you read this article and you're disappointed I didn't tell you exactly how to get to net-zero with all the tech trade industry specifics, feel free to reach out to me via email. I'm always happy to get into the weeds on how the technologies work and how they can be combined. All you need to do is run into one of my past students to know, I love to talk about this stuff! So reach out, leave me a comment, send me an email, start a discussion with me on Facebook. I promise, I'll respond!~ Emily Mottram, Mottram Architecture
Why You Should Super Insulate Your Home
What does it mean to build a super insulated home? I often get asked what my recommendation for insulation is. Both the type of insulation to use, and how much. But let me ask you a different question. What are you really looking for in your home? Comfort? Savings? Seriously I've never asked a group full of people if they'd like to spend less on utilities and had them say no! Maybe you're ready for retirement and you want to be able to shut it down for the winter and go south. Wouldn't it be great not to worry about frozen pipes or high heating costs when you're not there? But maybe you're the person who has to have beautiful granite countertops? Let me ask you, do you want to build a brand new dream home with all the interior bells and whistles and then sit around with three sweatshirts because it’s drafty or cold? If you answered, "Yes. I don't care how much it costs i'll just turn the heat up" then you should probably stop reading now. For us, we'd rather do the "hard to change" things right the first time, and come back and add the bells and whistles when we aren't using as much to operate our homes.There are so many components that go into a super insulated home. Simple things that have no cost like orienting your house the right direction. Or taking the time to think about where windows are positioned and how they are positioned. Our favorite thing to do isn't to spend thousands of dollars on windows, but to pick the right ones in the right locations, and minimize them everywhere else. These two things make a huge impact on the quality of the space within the home. If you've met me, you know I always say "Every house has an ugly side, let's make it the North side". Building a super insulated home may not be about the flashy and attractive things that people see when they walk into your house. Instead, it's about comfort. Super insulated homes are designed for the people inside. There are three things that affect our comfort levels: Temperature, Air Movement, and Humidity. Super insulated homes reduce air infiltration, heat loss, and control the interior moisture. They are specifically designed more maximum comfort. Reducing the unhappiness of the occupant significantly reduces the use of energy in the home. So let us tell you a little bit more about the “less beautiful” parts of your home that actually make your space so much more attractive.Tip number 1: Improving the insulation in your home is the hardest thing to do after it's built, and let's be honest, you'll never do it. So don't skimp on this part. Don't let this be the first thing you ask your builder to compromise on. If your budget is tight, let us tell you what things to do later that are super easy to replace or add. So let me give you my thoughts on insulation:
- All of my builders know not to utter the word “fiberglass insulation” in my presence unless we are talking about how to insulate a bedroom or bathroom for sound transmission. Fiberglass is cheap and cheerful and always installed by the guy who gets paid the least on the crew. It’s rarely installed correctly and it’s even more rarely installed in a vacuum (ie completely air tight cavity). Fiberglass insulation works by trapping air pockets in between all the fibers, however, building is rarely 100% air tight, so when air moves though the fiberglass fibers it eliminates the pockets of air and makes the fiberglass insulation more of a filter and less of an insulator. We’ve all seen dirty fiberglass, and that’s why.
- Cellulose, we love cellulose and use it almost exclusively in our projects. A properly dense packed wall will move and shift with the building as it drys out after construction. Dense packed cellulose insulation retards air infiltration making the house tighter and the insulation more effective. And it’s fire resistant. Yes, it can hold 130% of it’s weight in water if it gets wet. Although it’s not possible to make a completely air-tight structure, we are in the practice of making water tight structures, so we worry very little about moisture getting into our wall cavities. Does it mean it never happens, no, but we’ve had so few problems with it we would not hesitate to recommend it.
- Spray foam is probably the 3rd most popular insulation choice. Like all of the insulations it has good and bad properties. It air seals very well and can make extremely tight buildings. But it’s also a solid insulation, so when the building settles and dries out over the first couple of years, it can crack and pull away from the structure. It’s also pretty nasty, most foams are made of plastic and the agent that is used to make it liquid to install, cure, and dry is often toxic requiring specific equipment to install it and mandatory building evacuation for 24 hours or more. It’s not flame resistant and has to be covered by a 15 minute thermal barrier or sheetrock which can add expense and only gives you time to get out of the building. Once it starts burning it gives off toxic fumes that are extremely dangerous.
Here's the nitty gritty. When someone asks me for my recommendation on insulation I recommend the following: R-40 in the walls and R-60 in the ceiling. In cold climate building we also add 2”-6” of rigid foam below the slab. To get a little more complicated, I also try to minimize something we call thermal bridging. Essentially, thermal bridging is a path from the interior to the exterior of the home with little to no insulation. If you think of a standard wall construction, you have studs with insulation in between the studs. The thermal bridge happens at the studs. Wood has an R-value of 1 per inch. Everywhere you have a stud in a typical wall it has an R-value of 5.5 in a 2x6 construction. In between each stud you have insulation with an R-value of 19. So the stud at 5.5 is the poorest performing section of your wall and a direct path for cold to transfer from outside to inside.And lastly, but most importantly, super insulated homes aim to be as air tight as possible. Every seam, crack, gap, or location where two materials meet is sealed with foam or caulking. It’s a common misconception that buildings need to breath. People need to breath, buildings don’t. Does that mean you don’t need fresh air? Absolutely not!!! What it means is that we control how much and where that air comes from. Instead of travelling through your dusty insulation and your dirty basement, we introduce that fresh air directly from outside. In addition to being able to control where the air comes from, it's equally as important to control how much air comes in. Most people probably remember from high school science that hot air rises. Well when that air rises and exits through your attic you have to heat the air that comes in to replace it. So the draftier your house is, the more it costs to keep it warm. And if you remember from a couple paragraphs ago, our comfort levels are directly affected by air movement.Yes, I'm asking you to spend more during construction to put in better insulation and air seal everything you possibly can. But if I could prove it would pay for itself in a very short amount of time, would you be interested in knowing how long?We hope you’ll visit again to learn more about insulation, windows, geo thermal and air source heat pumps, zero energy, and lots of other cool building related topics over the next couple of months. Reach out to us and let us know your questions, we are always happy to answer any questions you might have, and several other people reading this blog may have the same exact question, so you’re doing them a favor by reaching out!Until next time, have a warm and comfortable life!
Your House is a System
I think it’s time for me to introduce my readers to one of the most important concepts of building eco friendly homes. House as a System.What do I mean when I say your house is a system? It is a combination of inter-dependent parts that make up a whole building. As an energy professional and an architect, that means, if I chose to change one part, I am affecting other parts of the system. This may be in a good way, or it may be in a harmful way. With the emergence of building tight homes, we also need to be aware of what we are trapping inside that previously exited though drafty or leaky areas in the home. I was going to write “older homes”, but my experience as an energy auditor has taught me that it has little to do with the age of the home. There are just as many leaky, drafty, inefficient new homes as there are older homes.It is extremely important today to understand the impacts of building more efficient homes. This rule applies to architects, builders, and energy professionals. The chemicals found in our building materials can be very harmful to your health. Many products are made with formaldehyde or high volatile organic compounds (VOC’s). Maine also has high levels of radon due to the rocky ledge that makes up our soils. By building tighter homes, we must be sure we are not trapping harmful gases or compounds within the home.Building tighter homes isn’t just about air sealing with caulks and spray foams. Adding dense packed cellulose to your walls increases the insulation value of your home, but it also reduces the air infiltration. When we reduce the air infiltration we can cause our atmospherically drafting heating appliance to blow exhaust fumes back into the home instead of out through the chimney. We can trap moisture within the home, propagating mold growth and moisture damage. Many building professionals believe that houses needed to breath and that is simply untrue. Houses do not need to breath, the occupants do. And we need to be sure that the air our homeowners are breathing is both healthy and adequate.Houses that breathe draw in outdoor air from anywhere there is a hole or crack in the building structure. This often times means that air is coming in from your basement. When you think about the principle that hot air rises, you can imagine the cool air being drawn in from your basement and leaking the heated air out through your attic. Now if you think about your basement, you may be thinking about a dirt floor, all the chemicals you store there, or your heating system. All that air that is being drawn in through your basement is introducing those chemicals into your living space. We have a tendency to think of our basements as outside of our living space, but they are very much connected to every other part of your home. Although the things you store there may be out of sight, out of mind, they are definitely not out of the air you breath.Before the emergence of energy efficient and airtight building, homes were able to dry out due to the air movement through the structure and the lack of insulation in the walls. The homes would dry during the wet seasons of the spring and fall, however, these same homes would become very difficult and expensive to heat during the winter. The energy community knew they needed to button up the homes, but at the time, they did not know that they needed to provide mechanical ventilation for healthy indoor air quality and they created several sick buildings.Now we talk about passive house building where there are less then 15 quarter-size gaps, cracks, or holes in a building structure and the sun heats the home virtually eliminating the need for a heating system. These inter-dependent parts create a very efficient design. In passive house standards, it extremely important to provide mechanical ventilation to the space. Providing fresh outdoor air to the occupants of the home eliminates harmful byproducts from the construction materials and excess moisture from cooking, breathing, and showering. Because the home itself has very little air infiltration, mechanical ventilation is often provided by a heat recovery ventilator or energy recovery ventilator. This allows the system to provide fresh air directly to the locations of the home that need it, like the bedroom, where you spend most of your time while you are at home. Providing air directly to the locations where it is needed instead of drawing it in from wherever there are cracks in the foundation allows for the system to perform with precise calculations and reduces any loss associated with providing healthy indoor air quality.The increased levels of insulation from the code minimum help to keep heat within the building envelope. Large south-facing windows can take advantage of the sun and heat the home through heating thermal mass, often a concrete floor. All parts of that system have to work precisely together to make the house as efficient as possible. If a new homeowner came in and decided to throw a carpet over the concrete floor they would reverse the effects of the solar heating system and require a larger heating system to be installed. Tighter homes often do not have large gas cook stoves with 300 to 600 CFM ventilation hoods because there is simply not enough air infiltration to provide adequate supply to the ventilation system. Without that adequate air it causes the ventilation system to “suck” on the house and will quickly burn out the motor in the fan.These are just a few examples of how the components of your home work as a system. So as you are building your home and thinking about making something that is more efficient, make sure you consider hiring a professional who can provide you with the information you need to save money, but also provide you with a safe and comfortable home. It may sound daunting to build an energy efficient home, but the comfort level it can provide you and the energy it can save you is well worth the added considerations during the design or renovation process.
5 Easy Things To Do This Summer To Improve the Efficiency of Your Home
- Have an energy audit done
Having a qualified energy audit done will be the best money you have ever spent on your home, especially if you are considering turning your camp into a year round home. Energy Advisors through Efficiency Maine are required to have certifications that take into account not only the energy performance of your home, but the health, safety, and welfare of your family as well. So look at the participating energy advisors on the Efficiency Maine list when selecting an energy auditor in your area. Having an audit done in the middle of the summer is just as effective as having an audit done in the winter.To find a Qualified Energy Professional in your Area click HERE
- Buy a couple tubes of caulking and seal around your window trim
Please don’t let the window manufacturer tell you they can save you tons of money on your energy bills by installing new windows. New windows are costly and the insulation value of a new window (R-3 to R-5) isn’t that much better then the existing R-2 window you currently have. What makes windows more efficient these days is the installation. Everyone has seen installers stuff fiberglass insulation around the window and cover it with trim. Well this doesn’t stop airflow from the exterior. New windows are now installed with low expanding spray foam around the gaps prior to installing trim. This cuts down on the air infiltration around the window making it feel less drafty. Don’t get me wrong, who doesn’t love new windows! But don’t be fooled into thinking they will pay for themselves. They are the most expensive energy upgrade you can make to your home. Instead, go to your local hardware store and buy a tube of caulking and seal around every seam of your window trim. Or, if you’re handy, pop the trim off and seal around the windows with low expanding spray foam. If you own an older home and the window trim has been painted numerous times over the years, this may not be a possibility, but caulking is a great and cheap option that most homeowners can do on their own!For a great homeowner how to video click HERE!
- Air seal attic penetrations
Everyone has heard the term, heat rises! So one of the best places to start making energy improvements is in your attic. If you have fiberglass insulation, simply lift the fiberglass insulation and look for areas where pipes, wires, light fixtures, or walls penetrate your ceiling. If the gap is bigger then ¼” seal it with a can of spray foam, if its smaller then ¼” then seal it with caulking. And last, but not least, if it’s a chimney or flue pipe seal it with high temperature foam or caulking! Lay your insulation back down over the top of your air sealing efforts and start counting the dollars you will save!
- Have your boiler serviced
This may seem like a no brainer, but having your boiler serviced will help you get the most out of every gallon of oil you put into it. Oil is dirty and tends to clog your boiler over time. It is recommended to have your oil boiler cleaned, tuned, and serviced every year. I highly recommend having this done in September right before heating season starts. Just like your car, a tune-up will go a long way on extending the life of your system and getting you the maximum efficiency over the long Maine heating season!
- Insulate your basement or attic
As mentioned above, heat rises, so the best places to start insulating your home are the basement or the attic. If heat can’t escape out of the top, it can’t pull in cold air from the bottom. The same applies in reverse. If cold air can’t be drawn in from below, less escapes out the top. So, after having an energy audit, consider insulating your attic. Most often I recommend cellulose in the attic and spray foam for rubble or granite basements or foil faced rigid insulation for smooth concrete walls. If you have smooth concrete walls and you’re just a little handy you can insulate you basement on your own for a really affordable cost!It is critical and important to have an energy audit done on your home prior to installing any insulation or air sealing practices. Moisture and indoor contaminants can become a problem after insulation and air sealing if a qualified professional hasn’t evaluated your home and given you proper techniques and practices to keep you and your family safe!
Why Fiberglass Insulation Sucks!
While I was teaching the last couple of days, several issues came up and one of them was fiberglass insulation. I tell my students at the beginning of the semester that I hate fiberglass insulation and very rarely use it, but that’s not really fair or true. Used in the right context, fiberglass insulation can be just fine. However, I find all too often that fiberglass is used in the wrong way. It really is not great as wall or attic insulation and it’s often found in basement ceilings where it’s installed up side down. So I thought it would be good to discuss when and where to use fiberglass insulation, and why it doesn’t work in all locations.First, fiberglass insulation works by trapping the air in between the fiberglass fibers. So fiberglass insulation is really only effective when there is absolutely no air movement where it is installed. Air movement through the insulation removes those trapped pockets of air and essentially makes it a filter. And no matter how tight you build a building, you are still going to have air leakage in some areas. That’s why; when you pull it out of the box sill in your basement it looks black. That’s just the air infiltration from the box sill being filtered through your insulation and making it useless, since it is no longer trapping air pockets within its web of fibers.The box sill or band joist, is often one of the leakiest locations in a home, and therefore one of the worst places to install fiberglass insulation. Fiberglass insulation rarely works well in the wall cavity because your siding breathes and tongue and grove wall surfaces are not airtight. Wall cavities can also be open to the box sill below. If you follow the principle that hot air rises, then that air is always going to be traveling up through your wall cavities, taking warm air with it, and cooling off the sheetrock on the inside. It also performs poorly in the attic due to wind washing. Wind washing is the effect that happens when the air enters your attic through your soffit venting and blows through the insulation. Contractors install proper vents to try to direct the air above the insulation. But I have been in many homes that have improperly sized or installed proper vents, or none at all. Not installing the proper vents and insulation dam causes the wind to be pulled through the fiberglass insulation, again releasing the trapped air molecules in the fiberglass and making the insulation less effective.If you have a heating system, plumbing, or laundry in your basement then the insulation does not belong in your basement ceiling. People argue with me all the time that they do that just to make the floors warmer; well that’s not a good enough reason. You’ll be thanking me when you don’t have frozen pipes and the excess heat from your boiler can rise to the floors above. If you have any of the things I mentioned in your basement then the thermal boundary of your space is the wall. If you have rubble stone or granite the best wall insulation is spray foam. If you have smooth concrete then the best insulation is rigid insulation. If you live in Maine the rigid insulation needs to be Thermax insulation approved by the Maine State Fire Marshal’s office for use without covering. Otherwise, you have to cover your rigid insulation with a 15 minute thermal barrier – which is 1/2” Sheetrock or ¾” OSB. You are also required to cover your spray foam insulation with a thermal barrier that any spray foam installer can spray on as part of the insulation process.But I digress, we were talking about fiberglass, and why it seems to always be installed in the wrong place or the wrong way. The Kraft paper side of the fiberglass always needs to be to the warm side of the structure. So in Maine, it needs to face to the inside. Fiberglass is only as good as it is installed. The Kraft paper should be face stapled to the studs, not side stapled which compresses the insulation. The fiberglass insulation should be cut and fit around electrical wiring so that it is not compressed behind the wire. And it needs to fit fully into the cavity, touching both sides of the studs, as well as, the top and bottom. All too often insulation is installed by the lowest paid guy on the job site. It’s one of the most critical pieces to get right, but it’s nasty work and therefore done by the new guy. In basements, the Kraft paper side needs to be up against the warm floor above, not stapled to the floor joists below– I know this is easier to install, but it’s putting the vapor barrier on the wrong side. And in the North East we strap our ceilings, which makes fiberglass insulation the worst type of insulation to use in your attic. The ¾” strapping leaves a ¾” gap between the ceiling sheetrock and the insulation above allowing air to carry the heat away from the sheetrock without the protection of the insulation. That moving air also reduces the effectiveness of the insulation above. So make sure that your insulation is in full contact with your sheetrock ceiling. The proper way to solve this problem without adding a lot of extra expense is to pick up your fiberglass insulation, blow in 3 inches of cellulose, cut the vapor barrier on your existing fiberglass insulation and lay it back down on top of the cellulose. If you need more insulation to meet the code minimum, blow an additional couple of inches of cellulose over the top of your fiberglass insulation to make a fiberglass sandwich. The density of the cellulose minimizes the airflow through the insulation and makes the fiberglass more effective.Where would I use fiberglass? Well it makes a great sound barrier, so I would use it around the master bedroom and around bathrooms to reduce noise levels. I would also use fiberglass insulation in conjunction with rigid insulation in basements if you were going to finish a basement, because it does not hold water, and basements can be moist. It has its place, in a completely sealed envelope it can add a lot of r-value to a system, but it needs to be installed correctly and in the right location.
What is R-value?
I want to talk about windows, insulation, and envelop upgrades but I think the fundamentals of R-value should be discussed first. It will help in understanding how all the parts go together when one understands the importance of R-value.R-value, is the measurement of thermal resistance used in the building and construction industry. It is also the inverse of U-value. Heat is transferred through conduction, convection and radiation. If your eyes just crossed remembering your high school science days, you’re not alone. This is one of the basics that I teach at the beginning of my building science class, and I repeat at the beginning of my sustainable design class. Let’s discuss what they mean for you, the homeowner.For most people, R-value is often seen on bags of insulation. It can be found for other building materials such as wood studs, drywall, siding etc, but is not often displayed on the packaging. U-value, thermal transmittance, is usually observed on windows and doors. If you have looked at windows, you have seen the U-value listed because it is required as part of the building industry standards. You may not have known what it meant at the time, but that little number is very important. And contrary to everything else you have ever learned, the smaller the number, the better the window! It is also good to know that U-value is the inverse of R-value. For example, if a window has a U-value of 0.30, its R-value is 3.3. It’s easier to compare the performance of building components when they are listed in the same format. For comparison, the current IECC 2009 for the Northeast requires walls to have a minimum R-value of R-21. So if you look at the window with an R-3.3, and then at the wall with an R-21, you’ll see that the window is a fairly poor performing part of your building envelop. But I digress; there will be more articles all about windows in the future.R-value gives the building professional an idea the materials ability to resist heat flow. It also works in the opposite direction with the heat entering your home in the summer or primarily cooling climate locations. Every state has a building code, and each building code has a minimum level of R-value necessary to meet the states requirements. In some places in the country they also have additional requirements that have higher performance levels then code. Again, this is a reason why you can’t afford not to hire an architect, and more specifically, one that knows a lot about energy efficiency.For an energy professional, R-value can translate directly into how many Btu’s your home will use. A Btu (British Thermal Unit) is the amount of energy needed to raise one pound of water one degree F. For building professionals it is the rate at which your home loses heat through the surface (walls, windows, roof, doors) and through air changes (how drafty your home is) The higher the R-value the lower the surface transported heat loss. The building professional will take the R-value, include the air transported heat loss, and tell you approximately how many Btu’s your homes heating system will need to produce to keep you warm this winter.From here it gets complicated. The air transported heat loss can have an effect on how well the R-value of certain building products perform. The tighter the house becomes the harder it is for standard atmospheric heating systems to work. But the more efficient your home is, the less it will cost you to live in and operate. So the next time you’re concerned about insulation, drafts, and R-value think about hiring an energy professional to help you out, because replacing your windows isn’t the best place to start.
