You may or may not have seen that Bensonwood is rolling out a new division of their company called Tektoniks where they are combining their knowledge from Bensonwood and Unity homes to help supply the market with something it desperately needs: Better Homes with Panelized ConstructionPrefab, modular and panelized construction has gotten a bad name over the years. People often associate it with low quality housing, but that's not really the case. Look back to the start of kit housing and the Sears catalog and you'll see that they sold over 70,000 homes between 1902 and 1940. The kit of parts was delivered to the site and often raised in a "barn raising" type style. It supplied a need for housing in the country that was quick and affordable. And to be honest, pretty stylish.Somewhere along the lines we lost some of that stylish design, the adherence to quality, and the ability to move forward in the building industry building BETTER homes, not just cheaper homes.But I digress, what does panelized construction have to do with today's housing needs? As an architect working with zero energy and super insulated houses, I find panelized construction fascinating. We've been using it on one of our developments in Maine for the last several years.
We started with a framer that builds the walls in a shop, delivers them to the site, and 3 days later we have a shell. Framing them in the shop cuts down on time, often taking a 9-12 month build down to 6 months. The quality control and material control can cut waste and job site debris down by almost 25%. And when you're building indoors, weather delays aren't an issue. So while the site is being prepped, framing is happening at the same time. But our framer, he's busy. I wish we had 2 or 3 more to help with construction right now.But how are they different? Why is this different than SIPS panels or modular construction? These are prototypes of zero energy homes. We spend hours in design development working out the systems to cut down on thermal bridging, orient the home the right direction, and provide really great spaces. We are very strict about the materials we use cutting out as much foams, plastics, and formaldehyde products. They are custom homes where we eliminate as much square footage as possible while still spending the time to make spacious areas and a spot for everything. More square footage isn't better, it's just more. In a world where we are seeing people going back to their roots, wanting less, spending more time outside of the home or in a community, this seems like the right answer. Minimizing the impact of building, the buildings impact on environment, and most importantly celebrating it's impact on the occupants. Our health and welfare can be directly linked to where we live.So why aren't we building better? Well the answer is, here at Mottram Architecture, we are.Stay tuned for updates on how the next Live Solar Maine house is going:
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.
