At Mottram Architecture we are passionate about promoting and practicing sustainable living and integrated design. Our energy efficient building design approach helps our clients achieve a healthy home and make a positive impact on their community and our environment. There are countless ways you can get involved and become an advocate of energy conservation.What is Net-Zero“A zero-energy building, also known as a net-zero energy building is a building with zero net energy consumption, meaning the total amount of energy used by the building on an annual basis is roughly equal to the amount of renewable energy created on the site.” (by D. Crawley U.S. Department of Energy). These homes do at times use non-renewable energy however it is counterbalanced by the amount of renewable energy used, giving a net balance of zero energy consumption. There are also homes that create a surplus of energy referred to as “Positive Energy Buildings”. Similarly there are homes that are considered “Ultra-Low Energy homes” which consume a marginal amount more than they produce. To achieve this goal the home must: 1. Be designed to use less energy 2. Maximize the use of on-site and renewable energy sources. Building a new home has advantages over retrofitting to reach Net-Zero status. For example an important factor such as building orientation for optimal solar exposure can be designed and planned in the design phase of a new build. All net zero homes start with good design. At Mottram Architecture these are the principles that we use to develop our Net Zero Homes in Maine. Net Zero might be more challenging to achieve through a retrofit, however any energy conscious renovation is guaranteed to make an immediate and obvious difference.How You Can Get InvolvedIf you're interested in renovating your existing home, there are many things you can do to drastically increase the efficiency. An Energy Audit is the best way to understand what your home needs. Here at Mottram Architecture we perform Energy Audits for our clients, as part of all of our renovation work, to pinpoint inefficiencies of the home. The results of the energy audit will prioritize improvements that will have the highest impact on the health and energy consumption of your home. If your just getting introduced to the concept of sustainable living and are interested in some DIY strategies here are some simple, low cost, steps you can take to significantly reduce your energy use.No matter what motivates you, saving money or saving the environment, small changes can have big impacts. If you want to consider Net Zero but need more information, contact us today! We offer a feasibility study that can help get you started by pinpointing what works for your budget, your site, your family and your goals. Start your path to Net-Zero today, you won't be sorry!Resources"Zero Energy Buildings: A Critical Look at the Definition" Paul Torcellini, Shanti Pless, and Michael Deru, National Renewable Energy Laboratory; Drury Crawley, U.S. Department of Energy. National Renewable Energy Laboratory report: NREL/CP-550-39833. June, 2006. http://www.nrel.gov/docs/fy06osti/39833.pdf
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.
Thanks for checking back in over the last couple of weeks to see the sneak peaks of this recently completed remodel! I told you last week that I would let you in on my favorite part of this whole renovation this last Friday in March! Well here it is: Insulation!!! I know, you were expecting something beautiful, fun, classy and wonderful. Don't be disappointed, this is absolutely our favorite part of this whole project. Of course we get excited about the beautiful things that we created here, but what we are most proud of, is that quiet comfort that is now found within this home. One of the reasons this homeowner reached out to us, was because of our specialty in energy efficient design. They loved their timber frame home, which already faces south, but there were challenges that just didn't work for their family. Functionality of space, the need to put wood in the wood stove, the questionable railing on the second floor and a particularly energetic 7 year old...the list goes on. But what they really wanted to know was, where are we losing energy? If we're going to do this renovation project, can we do some of these things to help improve the efficiency at the same time? And the answer of course is "We'd love for you to do that, let us show you how" Because this house is a timber frame, it had board ceilings. Although they are beautiful, the let the air leak right through the boards. And I'd love to say, that due to the age of the home, they had fiberglass insulation behind the boards, but the sad fact is, we still build this way today, and that's just not okay. So here, we took down the boards and salvaged them for the homeowner. Then we dense packed the rafter cavities with cellulose to improve the insulation and greatly cut down on air infiltration. We went back and forth but finally decided that sheet rocking the ceiling in the main space would brighten up the living area, so the boards were salvaged for a later project. (Replacing all the trim with flat stock casing, maybe a new bar in the sunroom, or if the 7 year old wins, a new ninja warrior course, oh the possibilities!!!). Now when you step into this home it is quiet. If they want to run the wood stove, they do, but they don't have to. The sun pours in the south windows and keeps the interior of the house warm all day long. Sometimes it's the simple things that you can't see that make a space truly wonderful.
I could not be more excited to share this project!In 2014 we started a partnership with Live Solar Maine to bring Net-Zero to the market in a really clever and creative way. Here's a little bit more about this project.Context: Live Solar Maine wants to bring Net-Zero to the everyday homeowner. This home was built on a piece of property that was inhumanely harvested. In order to give back to the land and provide something really meaningful, we created Net-Zero 1. Net-Zero 1 is a classic farmhouse with a modern twist. Maine has some really classic design styles and we wanted to stay true to some classic features while keeping it simple, modern, up to date, and cost effective!Conclusion: This project is small at just under 1800SF, but it feels big and spacious! The south sun pours in the windows in the winter and is shaded by your classic front porch in the summer. The walls are 9.25" thick giving that old deep farmhouse window sill feeling and they are low the the ground so you feel like you are a part of the outdoors from the inside.Energy Efficiency: Net-Zero means that at the end of the year you produced more energy then you used. In this house it works in a number of different ways. First, the building envelop is tight and super insulated and the house is oriented for optimal solar exposure. This is the hardest thing to go back and fix after the fact, so we feel that this should be done right from the beginning. It's not passive house, and has a blower door number around 1.5 ACH. We think that between 1-2 ACH is a really comfortable number where passive mechanical ventilation really provides more then enough fresh air to get rid of excess moisture and contaminants. So air tightness is number one, followed by super insulated walls, foundations, and ceilings. And then passive ventilation. It's so incredibly important to ventilate these super tight houses, but it's also important that the mechanicals are simple and easy to use. We love a passive air intake coupled with Panasonic Whisper Green fans in each bathroom. Simple, easy, and effective. Then we have heat-pumps that run the space, absolutely not fossil fuels, and PV to cover the electrical usage. This model house is even equipped to install a car charger when or if the homeowner is ready to take advantage of the electric car revolution.Now, I say we call this house Net-Zero 1 because it truly has the potential to be net positive. However, every house is completely dependent on the occupants. We can control the performance of the structure, but it comes down to how every individual lives as to whether or not net-zero is achievable!Until next time - stay tuned for more on Live Solar Maine breaking ground in 2017!
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.
Tighten a home that has moisture issues
Energy efficiency can be directly related to the warm air leaking out of your home. So most of us understand that air sealing and tightening our homes will make them more energy efficient. That is correct, but it is extremely important to eliminate moisture problems before we do so. Moisture trapped within the home creates condensation, structural damage, mold growth, and poor indoor air quality. Sources of moisture can be dirt basements and crawlspaces, un-sealed concrete slabs or walls, fish tanks, cooking with gas, cooking without lids on pots, shower areas, excessive amounts of plants, greenhouse open to the living space, standing water, bathroom or laundry vents not vented to the exterior, uncovered sump pumps and many other sources. The best course of action is to eliminate the moisture source before air sealing the home. If you can’t eliminate the source, encapsulate it. If you can’t encapsulate it, try to diffuse it.
Replace the windows first
Windows are very costly. Rarely do windows pay for themselves in energy retrofits before the lifespan of the window is considered over. Who wants to wait 25, 35, or 45 plus years for their windows to pay for themselves? The current energy standards only require you to put R- 3.3 windows in your home. That’s hardly better then the R-2 double hung window that you currently have. The most cost effective solution for window retrofits is air sealing the window during installation, not the actual window itself. So before you replace those leaky windows, see if you can remove the trim and air seal around the window. If you have a broken window, or a window with condensation between the panes of glass that would be an appropriate time to replace the window. Also, if you have a very old home with weight and chain windows, it might be in your best interest to replace the windows. The weight and chain cavity of a window allows significant air leakage into the home and cannot be effectively sealed without changing the operation of the window.
Not have a qualified energy professional evaluate your home
Many contractors will tell you that you don’t need to hire an energy professional to evaluate your home. However, energy professionals are trained in both evaluation and safety. A good energy auditor will not only evaluate your home but provide diagnostic testing to locate the worst performing sections to tackle those first. In addition, an energy auditor should be checking your home for air quality issues like back-drafting furnaces, poorly performing ventilation systems, leaky gas lines, and excess toxins and moisture. They should be able to provide you with a prioritized list of energy improvements, and come back to test the air quality and heating system safety after the work has been completed. Simply adding more insulation to your attic without addressing potential problems is a waste of your time and money.
Insulate your attic without air sealing first
As I mentioned above, adding extra insulation does not mean that you are adding energy improvements. Attic spaces tend to have several openings between the living space and the cold attic. That air movement from the living space into the attic increases heat loss in your home and also transfers warm moist air to the attic. That warm moist air will often condense on the roof sheathing and cause premature roof failure and mold growth. Insulation is not meant to retard airflow; it’s meant to reduce conductive heat flow through the ceiling material. So if your insulation isn’t in full contact with your sheetrock or plaster ceiling it is not an effective thermal barrier. This can happen due to strapping on a ceiling or insulation that fits poorly within a space. Air is constantly flowing between the surface of the ceiling and the surface of the insulation taking heat with it. The areas around penetrations in the ceiling are drawing air, because heat rises, up through those holes with little resistance. Fiberglass insulation becomes a filter for that air, but does not stop it. Cellulose insulation can reduce the flow, but also does not stop it. So the first course of action when adding insulation to your attic is to air seal around all penetrations [pluming, electrical, mechanical, chimney’s, open wall cavities, etc] prior to adding a layer of insulation. Then be sure that the type of insulation you install will fit fully against the ceiling surface below.
Forget the attic hatch
As little as a 7% void in insulation can cause up to 50% of the heat loss through your attic. Having an un-insulated attic hatch adjacent to your R-49 attic space can result in a significant amount of heat loss. Your heating system will work hard to continue to heat that hole in your ceiling. The attic hatch will be constantly giving heat to the attic and requiring heat to stay warm. Sometimes there is a fiberglass batt positioned on the top of the attic hatch, but the first time someone goes up through the hatch the batt is moved to the side and rarely replaced. Even if your attic hatch has insulation on it, the hatch is rarely air sealed allowing a significant amount of heat to enter the attic space around the board or sheetrock that acts as your attic hatch. So, even if you do have a fiberglass batt on top of your attic hatch, if it is not air sealed, that insulation is doing nothing.
Pretend the basement does not exist
Basements are an integral part of a building envelope, and although we like to pretend they do not exist they are some of the leading contributors to energy loss in a home. Concrete has virtually no R-value, so any section of above grade foundation that you have is continually leaking heat to the exterior of your home. You may notice that your flowers bloom early in the spring, and the snow melts directly against your foundation sooner then other areas. Basements also tend to be the place where we store our chemicals, firewood, paints, and install our heating systems. If you have poorly installed ductwork in your basement you can be transferring all of those indoor air pollutants directly to your living spaces. Any holes between the basement for plumbing, electrical, and mechanical directly introduce the moisture and toxins from your basement into the rest of your home. And insulating the basement ceiling isn’t going to stop that airflow, and often times can lead to frozen pipes and performance issues with your heating system. So before you say you want to do an energy project, but you don’t want to address your basement, remember that you could be creating a new issue that you did not have before.
Ignore the air barrier between the garage and living space
And last, but certainly not least, is ignoring the reasons why new construction codes require you to have a separation between your living space and your garage. For code purposes, several of the requirements relate to fire hazards. However, we have also learned in recent years, with the influx of tighter homes, that contaminants in the garage often leads to poor indoor air quality. Your car continues to give off carbon monoxide for hours after it is turned off. Similar to your basement, your garage is where you tend to store chemicals and gas for your lawn mower. For these reasons, it is very important that you have a continuous air barrier between your garage and living space. This includes attached garages and tuck under garages where the garage is below with a living space is above.Remember, your house is a system. Every part is directly or indirectly related to some other part. So hiring an energy professional to help you create a safe, comfortable, and energy efficient home isn’t just important, it’s critical.
- 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!
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.
As of September 15th it's heating season again. If you live in New England, or more specifically, Maine, then you know that means it's time to fill your tank with Fuel Oil again. It's a sad reality for me, that Natural Gas lines are less then .25 miles down the street, but just out of my reach. Our street was paved last year, and city ordinances require that you can not rip up the pavement for a certain number of years.I knew the city was going to pave our street, so prior to paving, I reached out to the natural gas company in our area. I was told that I would need to petition my neighbors and convince several of them on our street to switch to natural gas. If you are a homeowner or building owner, you know that replacing your heating system is a costly upgrade and very few people are willing to do so. Sure i'm an Energy Consultant and I could have run the numbers for all of my neighbors on the savings and payback for moving to natural gas - but let's be honest, who has that kind of time!So instead I leave you with a few nuggets of wisdom that I use when I do all of my residential energy audits.1. Have an Energy Audit done on your home. A great energy auditor is trained to understand your home as a system and figure out where air leaks are coming from and what the best solution for your individual home is. Even homes built from the exact same plans will be totally different, so make sure you hire the right energy auditor, that will give you an assessment on your unique home.2. Air sealing is the cheapest and nets you the most savings for the dollars you put in. Everyone has heard the term "hot air rises" so start in your attic - seal around anything that protrudes through your ceiling and into your attic space. Grab a tube of caulking and a can of 1-part spray foam from your local hardware store and make that first adventure into your attic. Air sealing isn't rocket science - but be very careful to stand on the joists and not fall through the ceiling. If you're not agile, or willing to climb around in your attic on a saturday afternoon there are plenty of hungry contractors out there willing to do the job!3. Add insulation - adding insulation to your attic is the best place to start because it is usually easy to get to. If you haven't done the air sealing mentioned in number 2, don't even bother with the insulation - you'll just be wasting your money.3. After you've done all the insulation and air sealing - then consider upgrading your heating system. You ask - why do I leave this for last - I have an old heating system and it will save me the money I need to add the air sealing and insulation. Well that might be true, but once you add the air sealing and insulation, your heating system will be oversized and you'll lose money from short cycling.So this heating season - as the leaves begin to fall and we start thinking about winter again - keep in mind - that a good energy audit can tell you a lot about your home, and save you money all year long.