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
Building Strategies: Building homes with Intelligent Designs
Are you thinking of building a new home? What qualities of a home are important to you? How about modern design, spaces with lots of natural light, well regulated heating & cooling for comfortable room temperatures? What if you had all of that plus reduced utility bills? If you’re passionate about loving your space, then your dream home might be a net zero design!With the exception of the alluring aesthetics of a net zero home, at first glance you might not realize it is out of the ordinary. What makes this type of home so special is the details that are working in harmony to make the space truly unique for you and your loved ones. If you are planning to build a home anyway, why not make some early decisions that can make your home smarter, cheaper to live in and more comfortable.A common misconception is the average consumer cannot afford to build to the standards of net zero, however this is a feasible goal for anyone ready to build! It’s possible to keep costs comparable to conventional construction simply by planning ahead, and that’s what we do best here at Mottram Architecture.When building with net zero in mind certain strategies drive design. Every material, angle, direction and appliance chosen has a higher purpose and function. The following details are some of the most important design choices to incorporate in your building plans to achieve a net zero home. Starting from the biggest choices down to the smallest hidden technicalities, every detail works together to make your home the best it can be.
- If you haven’t purchased land to build on yet, there are many characteristics you can look for when selecting your site. Natural elements to shelter you from the a cold climate and a direct line to sunlight will optimize your net zero potential. These features are ideal to help with temperature and access to natural resources to power your home. An external consideration to site selection is proximity to public transportation like the rail or bus. This can help reduce emissions and save money. With conventional construction, your site choice might be influenced by a popular or desired neighborhood.
- Facing south for optimal solar exposure is imperative for having the greatest ability to produce power directly from the source, your home! This also works as an advantage in cold climates like Maine because it allows for your home to be naturally heated by maximizing passive solar gain. With conventional construction, your homes orientation might be influenced by the landscape or neighboring homes.
- Simple and moderately sized homes can make the idea of net zero a reality. When a space is well planned out and designed with functionality in mind, an over-sized McMansion is no longer necessary. Keeping both these strategies in mind will save building costs and allow to allocate your money to more energy efficient appliances and materials. With conventional construction, your homes size and shape might be influenced by short-lived popular trends.
- Maximize your walls potential for insulation and resisting air infiltration, while clearly defining your heated spaces. With Mottram Architecture you will see optimal R-values in your walls, ceilings and floors. All of our structures will also have a continuous air barrier. The combination of these two details will reduce heat loss and drafts, which increase your comfort and decrease your bills. The whole idea is to define a thermal barrier which means, keep the heat inside and keep the weather outside! With conventional construction, your home is built to breath, a design that invites drafts and burns through your hard earned money.
- Choosing the right style and location of your windows. High R-value windows perform best but just by reducing the number of windows you need, placing them in the right locations and only have operating sections where needed, you can make a huge impact on the performance of your building and reduction of energy demand on the solar system. With conventional construction, your home is built fast and cheap. The type of window chosen is based on price and availability.
- For reasons mentioned above we are building a sealed home space which is why controlled mechanical ventilation is important. This will make your home safe and efficient. Duct work and equipment is best located within the heated spaces of your home. This ensures the system won't use extra resources to compensate for any external weather. With conventional construction, your home is leaky enough to vent naturally.
- In Maine with Mottram Architecture we are most likely to recommend a heat pump for our net zero homes. This type of heating system uses the natural outdoor & ground temperatures on your site to move heat in or out of your home. This system is more efficient because it’s moving instead of creating energy. With conventional construction, your home uses non-renewable resources like oil and gas to create energy to heat your home.
- Renewable power production: To truly be Net Zero we believe a home should produce more power on site than it consumes during the year. On site produced energy is most efficient when it is directly attached to the structure which is using the energy. In Maine that means solar. By following all the principles above we can reduce consumption of the home to a manageable amount of energy use that can be produced by a solar array.
Planning and attention to detail are the foundations to an intelligent design that will lead to a cost effective net zero energy home. If you think these designs align with you and your families goals and values engage Mottram Architecture to guide you through this conceptual process. We can help you identify what choices are right for you and your home and how you can create a long term space customized to your needs that will start giving back the day you move in!
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
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
Zero Energy Homes - The Modern Solar Farmhouse With Live Solar Maine
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!
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.
7 Things You Should Never Do When Improving the Efficiency Of Your Home
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.
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.
Heating Season Again
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.
