When I was in Poland in October I met with several different companies about their businesses and technologies. One of the companies was Norpolhaus, a joint Norwegian-Polish venture. Andrezej Król, is the president of the company and spoke to me about their activities.
Posts Tagged ‘passive house’
You may already be familiar with the Passive House movement. Homes built to that standard are entirely concerned with energy consumption from heating, cooling and plug load. The standard requires that homes be so well insulated that there is no need for a conventional furnace, but rather a pellet stove, baseboard heating or a heat pump will do. Because the standard focuses entirely on heating, builders attempting passive house certification will also sometimes combine it with other environmental certifications, such as LEED, which is concerned with overall building and occupant health. Now, however, there is a new building philosophy called Active House that was developed by several representatives, among others, those from Denmark and Holland. It has three main tenets: Occupants’ indoor comfort be maximized, Energy Consumption minimized and Environmental Conservation be considered at each building phase from design through use through end-of-life.
Instead of evaluating homes on a “points” basis the way LEED does, Active Houses are evaluated in a web on a scale from 1 to 4. “1” being the best and “4” the lowest. The idea is to achieve as many of the specific category demands as possible to create a broad web – 1s and 2s, the outer rings of the web, being preferable to 3s and 4s, the inner rings.
Comfort: The first category considered is indoor comfort. This is a broad and somewhat open-ended term and covers daylight, indoor temperature and indoor air quality.
- Thermal Environment: One occupant might be more interested in keeping a room warmer or cooler than another and that’s exactly what the creators of the Active House had in mind — individual desires of the occupants. To achieve this and to conserve energy, zoned heating and cooling are used for different floors and rooms. Further, through the use of low to no energy features including orientation of the building, heat stack design, operable windows and the maximizing cross breezes, the use of natural ventilation is optimized and mechanical ventilation (and therefore electricity consumption) is limited. Building envelopes are well-insulated, so the addition of a Heat Recovery Ventilator is usually necessary to allow fresh air to enter and moist, stale air to leave the building even on excessively cold or hot days when windows aren’t opened. HRVs also improve energy efficiency as they transfer the heat from the stale air leaving to the fresh air entering.
- Daylight: Of critical importance to a person’s mental and physical well-being is the amount and quality of daylight a building is designed to receive. With the fairly recent discovery of Seasonal Affective Disorder (SAD), most of us living in the Northern Hemisphere don’t receive enough natural daylight during the winter months, one of the consequences for some people being depression. Architects working to Active House philosophy are required to design homes with high quality daylight reaching as many lived-in rooms as possible (storage and utility rooms aren’t counted). The recommended daylight factor is 2% or higher, while the lowest score of evaluated rooms must be greater than 1% on average.
- Indoor Air Quality: The Active House standard requires a constant supply of fresh air into the building, whether through operable windows or an HRV or a combination of the two. The HRV also can be used to control indoor humidity levels ensuring a dry environment to prevent mould growth.
Energy: Since the operation of buildings worldwide consumes about 40% of all fossil fuels, an Active House aims to be light on the use of carbon-based fuels and nuclear energy. For example, a house that uses 100% renewable energy scores a “1”, while a house using 25% or more renewable energy would score a “4”.
- Energy Demand: This is the amount of energy required by the house, including space heating and cooling, water heating, lighting, ventilation, technical installations, plug load and appliances. In the design phase, architects will focus on designing a house that maximizes energy conservation and efficiency by taking advantage of passive solar gains for both lighting and heat, as well as designing tight building envelopes. Other features include the addition of renewable energy systems and demand-control ventilation, which also contribute to the energy savings. Use of dynamic building envelope with solar shadings and natural ventilations reduces the need for
mechanical cooling and air conditioning during summer period. Finally, the type of construction is very important to successful implementation of this phase.
- Energy Supply: The type and quality of energy supplied to the house is another important facet of the Active House philosophy. Homes that use 100% renewable energy produced on site or nearby receive a “1”. Homes that use 25% or more renewable energy receive a “4”. Note that not using any renewable energy isn’t even an option, regardless of how efficient you are.
- Primary Energy Performance: This value is the calculation of (total energy consumption – renewable energy supply) x national primary energy factors. What they are looking for here,, in principle, is your CO2 output based on the national, or in our case, provincial, energy production mix. If your home uses 100% renewable energy, either from the grid or produced all on-site your score would be “1”.
Environment: This is the area that focuses on building materials, waste and life cycle. The Active House is concerned not only with the functioning of the building, but how it got there and what will happen to it when its useful life is over.
- Environmental Load: Building a house is a disruptive process to the global environment. The Active House takes into account how damaging construction can be by considering a house’s Global Warming Potential, Primary Energy consumption, ozone depletion, smog potential, water acidification potential and eutrophication of the soil. The environmental load is all encompassing, and considers the whole Life Cycle, including the production and transportation of the materials used to build the house, the maintenance and operation of the house, and disposal of the house at end of life.
- Fresh water consumption: Minimizing consumption of freshwater by occupants’ also plays an important role in the Active House. A “1” is achieved by reducing water consumption by 50% versus the national average, while a “4” is graded for a house that conserves 10% or more. Devices and techniques used can be items such as a cistern to catch rain water or a gray water system, which captures used water from baths and showers and recirculates it to toilets. Low-flow fixtures can also be installed.
- Sustainable Construction: As many renewable and recycled/recyclable products are used in the construction of the house as possible. A house containing a minimum of 5% recyclable content will receive a “4” while a house that uses over 50% recycled content receives a 1. Regarding wood, the standard is more demanding. At least 50% of all wood used in construction of the house must be certified either by PEFC or FSC. 25-80% of new material needs to be EMS certified. If you’re not familiar with this requirement, EMS stands for Environmental Management System, usually referring to ISO 14001 standard which is a voluntary guideline outlining the criteria a company would have to go through to get ISO 14001 certification. A company with an EMS in place tends to have a greater responsibility with how its products are made, including taking steps towards responsible sourcing and improving its overall energy and water efficiency.
Qualitative parameters: In addition to the evaluative web used to rate an Active House, there is a long list of other considerations that are used to make this house a lower impact, thoughtfully designed house, which architects, designers and other building professionals can use as a guide. Other issues such as noise and acoustics, accessibility, visual transmittance and glare management among the factors considered.
The philosophy behind the design process is thorough, thoughtful and addresses gaps in the Passive House built house and even the LEED for Homes designation. It does not go as far as Living Building Challenge, which requires that most, if not all energy and water used by the house be produced or captured by the house. Perhaps though, it is a more realistic approach for urban dwellers. The developers of the Active House philosophy consider it a work in progress, not dissimilar to LEED. They evaluate houses already built to the standard to see how it can be improved. Homes are evaluated before and during occupancy and compared so that professionals involved in Active House design-build can learn from the results.
The first Canadian built Active House has just been completed in Thorold, Ontario by Great Gulf Homes. It provides an excellent example of the philosophy being put into practice. Stay tuned as I will discuss the features of that house in the next post.
For more information on the Active House philosophy, visit the website: http://www.activehouse.info/
The Active House Alliance is now in process of developing concept guidelines and classification for Active House projects, with an expected launch by the end of the year.
For two Active homes already built, see the following articles:
La Maison Aire et Lumiere (in French)
In 2007 we moved into a brand new house with the naive view that new was always better than old. My husband’s and my belief was that a new house would involve less maintenance, lower running costs, higher energy efficiency and overall fewer headaches. What happened over the course of the four years that we lived in that house was that I began to realize that new isn’t always better than old, particularly when you’re buying a builder’s home on spec as we did. While we did have lower running costs than in the previous house, a lot of it was due to the more efficient appliances, and slightly better insulation. We had more issues in this house in the first 3 years than we’d had in our two other previous 60+ year old homes. By the time we moved out four years later, I had come to a different conclusion: if I were to buy a new house again — and that was a big IF — I would only buy one that had been certified preferably LEED certified and preferably Platinum.
I’m not saying there aren’t excellent builders out there who go above and beyond their duty, making sure a new home will withstand the myriad of weather it’s exposed to — but there are also builders who will build to minimum code or less, and take shortcuts because not all shortcuts will be caught by building inspectors. Case in point: down the street from our house was another one going up by a different builder who didn’t bother to put tar paper down before adding the roof shingles. Will the building inspector find that? Only if he climbs up a ladder and lifts a shingle. Inaccessible areas such as behind walls, difficult to reach roofs, etc., hide a lot — there are many a poor electrical wiring jobs out there that are concealed behind walls (as we found out), many shoddy dry-walling jobs (as we found out), and some homes that are built before receiving the city’s approval for the water drainage system….as we also found out (sigh). We were fortunate because most of these things were fixed over time after a lot of threats, heated phone calls and emails, but I’ve also heard of cases where homeowners are out of luck — especially after the Tarion Warranty runs out.
I know there are builders out there who complain about the extra paper work and activity involved in certifying a home, and I understand, but I can also tell you that a certified home forces a builder to do it right, to not cut corners and to identify any mistakes before the walls are up and critical parts are covered. It likely saves a builder work in the long run. Maintenance costs tend to be lower and call backs from owners are much rarer. So really, if everyone puts the time, effort and money up front, it saves money, time and effort down the road and gives the buyer reassurance in the long-run.
Having said that, there are a lot of green building certifications out there from the ones we’ve all heard about like R-2000 to the lesser known ones like the Living Building Challenge. I thought I’d put a list of green building certifications available for homes and the priorities on which they focus. That way, if you’re looking for a new home, you can be sure to ask the builder which one of these his/her building company follows. If a builder doesn’t use any certification it doesn’t mean they aren’t building well, they may prefer to put their time and money into the structure instead of the paperwork. Ask for the names of former customers and check with them as to whether they’re satisfied with the end result. Doing your research up front may save you a lot of headaches down the road.
R-2000: The energy crisis in the 1970s prompted a re-examination of our previously cheap supply of fossil fuels. At that time a project by the Saskatchewan government featuring an energy efficient home was translated into a nationwide program by the Canadian government, called R-2000. Certain energy efficiency standards need to be met in order to qualify to be certified as an R-2000 home. All builders receive training and certification in order to build R-2000 homes. The criteria for an R-2000 home are revamped as new building techniques and technologies become available but the standard incorporates the latest in energy efficiency, building techniques and standards available.
The focus of the R-2000 home certification is about reaching a high level of energy efficiency through tight building envelopes. A qualifying home must pass a blower door test after it’s built by an independent R-2000 certifier and achieve at least a rating of 1.5 ACH (air changes per hour) at a pressure of 50 pascals depressurization. Further, it must address issues with indoor air quality such as even ventilation, circulation, moisture and air distribution throughout the house (however, there is no mention of off-gassing from adhesives, paints, stains, and other materials used in construction). The homes also contain such features as water conserving fixtures and building materials with recycled content. There also isn’t any mention of location as being an important factor in the home’s construction. In some of the other certifications, using previously used land, as well as land with easy access to shops, services and public transportation holds equal weight to how a home is constructed.
R-2000 homes are easier to find than some of the other certifications across Canada. Homes are verified by certified R-2000 building inspectors during the building process. While a conventionally built home emits approximately 5 tonnes of CO2 emissions yearly, an R-2000 home emits 30% less than that.
The Office of Energy and Efficiency of the Government of Canada provides a search page to find R-2000 home builders in every province.
For more information on R-2000 homes, see this page.
EnerGuide Rating System: This certification system is strictly about measuring your home’s energy performance using a scale rating of 1-100. Most older homes measure between 65-72. A conventional new home with no energy efficient upgrades measures 73-79, New homes with some energy efficiency features measure 80-90, while a home with little to no extra energy needs measures 91-100. A score of 80 or more is excellent.
An Energy auditor measures your home’s EnerGuide rating and the work can be performed on any home, built or not yet built. When constructing a new home, an energy auditor should be brought in early in the process as he/she can run the proposed design through energy modelling software to see how the proposed home should rate once constructed. He can also make suggestions about how to increase the home’s energy efficiency.
Energy Star Certified Homes: This certification is entirely about energy efficiency. The bottom line is that a home must score at least 80 on the EnerGuide scale in order to qualify. Other requirements are that, depending on where the home is located, it have between 2-2.5 air changes per hour at 50 pascals depressurization. Note that this is one half to one air changes more than an R-2000 home, meaning it is not quite as energy efficient as an R-2000 home (fewer air changes mean less air is leaking in and out of the home). Energy Star certified homes also need to be certified by an independent energy auditor who will do inspections while the home is being built in addition to the one final blower door test after the home is built. A new home will also contain Energy Star rated appliances and light fixtures. Basements will be insulated to the same degree as attic spaces. There is no requirement for the type of materials used or location of the home vis a vis services, amenities or public transportation.
For more information on Energy Star home requirements, see this information package (it is for Ontario requirements).
LEED (Leadership in Energy and Environmental Design) for Homes:The United States Green Building Council was established in 1998 with the intention of developing a system to encourage the building industry to build better buildings. The development and operating of buildings uses up to 40% of all energy consumed in North America, so reducing buildings’ energy demands is in everyone’s best interest. With that in mind, the USGBC developed the Leadership in Energy and Environmental Design designation — a standard which first came on the scene as a pilot project in 2000. In 2003 the Canada Green Building Council introduced a version of LEED more suited to the Canadian climate. The program has since undergone two revisions in the US and one in Canada. It is a constantly changing certification, as it should be, to both keep up with changes in technology and building techniques.
LEED is a more encompassing designation than either Energy Star or even R-2000 and it is available for every kind of building from large renovations of existing buildings to new buildings and homes, and now neighbourhoods. In fact, energy efficiency, while important, is only one category of a sustainably designed home. There are four levels of LEED, and each level can be reached by attaining a certain number of points in each of the eight categories.
The eight categories addressed by LEED are:
- Innovation and Design,
- Sustainable Sites,
- Location and Linkages,
- Water Efficiency,
- Energy and Atmosphere,
- Indoor Air Quality,
- Material Use, and
- Awareness and Education.
Innovation and Design awards points not covered in any of the other categories and promotes new ideas, technologies and local variables that come into play in any home construction.
Location and linkages, and Sustainable Sites take into account where a home is built, whether on previously unused greenspace or infill, or “brown land” (previously industrial, now unused land). The closer you are to services, amenities and public transportation the more points you earn.
Material use emphasizes responsible material use by awarding more points for material that is sourced from rapidly renewable sources (grasses, fast-growing wood, grains), sourcing locally-based materials and products earns more points, as does sourcing recycled and reused materials. Energy and Atmosphere focuses on building a tight building envelope with significant levels of insulation. Indoor Air Quality is also addressed, awarding points for using low VOC producing adhesives, glues, primers, paints and stains. Not only is it better for the homeowner it’s also better for the people applying the products who aren’t exposed to harmful chemicals. Water Efficiency ensures that the fixtures will be low-flow, possibly solar-heated and using an on-demand tank, and if budget permits, a grey water system. Education and Awareness is about teaching homeowners about their new home and how it best functions.
Depending on the number of points a home achieves in each area will designate it as Certified (45-59 points), Silver (60-74), Gold (75-89) or Platinum (90-136).
A LEED Rater, like an energy auditor, will visit a property twice, once during construction and once when it is complete, in order to assess and make sure construction is following its intended construction path.
Passive House: The passive house certification is another one that focuses strictly on energy efficiency. It was developed in Germany more than 20 years ago, and is used as a common standard for home building in Germany today. Homes must use a maximum of 15 kWh/m2 energy for heating, and 120 kWh/m2 per year for electrical plug load, including lighting. Fifteen kWh/m2 was chosen as the threshold because it is at this point that a traditional central heating system is no longer necessary. To achieve passive house standard, especially here in Canada, can be a particular challenge and involves a lot of insulation, superior windows and doors, and a conscientious effort to minimize plug load.
Energy modelling software is used during the design process to determine whether or not a building will achieve the passive house standard. It might be difficult to achieve in an urban environment depending on whether or not a house is situated so that it can take advantage of passive solar heat in the winter, and be shaded in the summer.
For more information visit Passive Buildings Canada.
Living Building Challenge: One of the newest certifications available, it’s also by far the toughest to achieve. At this point, I would say that it is a goal to which the entire building industry should aspire, but it will be done in baby steps. In comparison to the Living Building Challenge, achieving LEED Platinum is basically a cake walk. LBC is divided into 7 performance areas and goals are performance based, not prescriptive. The seven areas are:
- Equity and
The categories are further divided into a total of 20 requirements. The purpose of the LBC is to address such issues as inequity in international development (fair trade and encouraging better working conditions) and reducing the amount of energy used both to build a home as well as to run it. In fact, a home must be net-zero energy annually. An LBC home is only certified after one year of energy data has been collected to make sure it’s operating as intended. Materials chosen must be the lowest possible embodied energy and still provide superior insulation, although locally manufactured cement and steel qualify as noted in some of the case studies. A building must be built on previously used land, so no new building in a previous wilderness setting will qualify.
To find out more about the Living Building Challenge, visit the website. One really useful component of the website is the case study section where several buildings which are built to the standard are showcased along with what they achieved in each of the seven categories. In addition, the standard highlights “red” materials, as in, those materials which are to be avoided, such as PVC because of its detrimental effect on the environment. Alternatives are given for each of these materials in the case study section under the Materials category.
Net Zero Energy: The concept of a Net Zero Energy home is simple: produce as much energy as your house consumes over the course of one year. There will be times when you use more energy than your home can produce on its own, and there will be times when you will have excess energy. The concept also means that your home is grid-tied, as in, you draw power from the electrical grid, but you also feed into the grid when you generate excess power. While the concept is easy to understand, implementing it can be a challenge. Not only do you have to create a home that uses as little energy as possible to heat and cool it, a Net Zero Home, takes into account plug load; ie., how many appliances, stereos, computers, game consoles, etc., you have plugged in and drawing power. So, occupant behaviour in a Net Zero home is as important as how well-insulated a home is. It also means that renewable energy sources must be used, such as solar panels, wind turbines, etc., in order for a home to generate a certain amount of electricity — and, naturally, the more people you have living in the home, the more challenging designing a home it will be.
For more information on Net Zero Energy Homes, visit the Net Zero Energy Home Coalition website.
In October, 2010, I had the very fortunate opportunity to visit with Sylvia Cook, owner of Aerecura Rammed Earth Builders and owner of Ontario’s first rammed earth home, just after the beautiful walls had been finished. The roof, windows and main floor had yet to be installed, so it was a bit difficult to visualize the finished product. Just over a year later, Sylvia and her husband held a housewarming party so all of us interested parties could come and take a look at the finished product.
To recap: Sylvia, a retired physics teacher, and her husband, a retired English teacher, were determined to build one of the lowest possible embodied energy homes they could. When researching materials and styles of homes, she wanted to find a material that was local, abundantly available, durable, and contained a low-embodied energy. A rammed earth fit home all of her criteria. You can read my full interview with Sylvia here, and read about the goals of the rammed earth home here.
The house itself is on two and a half levels (an open office area above the kitchen looks down onto the living room). It has a beautiful view of the hollow the house sits beside. Terrell Wong, the architect designed it to take advantage of as many passive heating and cooling features it could, so it is oriented to face southwest with large windows on the south side and smaller ones on the north side. The upper clerestory windows can be opened in summer to let the heat escape while lower floor windows will open to draw in cooler evening air.
Now that the house is completel, I asked Sylvia a few follow-up questions:
1. If you were to build again, is there anything you would do differently? ie., lessons learned.
I’m disappointed with the amount of wood used just on the relatively small section of the house between the top of the rammed earth and the roof. In order to maintain the continuous insulation layer we used a double stud wall construction. Next time I would use SIPS for this part of the house, as well as for the roof.
I would overestimate the heating needed and use a radiant infloor hydronic system for the lower floor. I made the decision not to because it was hard to justify the installation expense for the small amount of heat needed, but am now having to get creative with other methods of supplying that heat. Another time I might even consider putting hydronics inside a rammed earth wall. I think it’s important to remember that any initial expense will be amortised over a very long period of time, even though I won’t personally be around for more than a tiny fraction of that.
2. What in the house is salvaged (I believe the stairs and cross beams are), and where did you source your salvaged material?
The stairs originally came from the Belleville CN roundhouse, circa 1840. The wonderfully quirky welder who made the railings onsite happened to have them stored in his barn. A fantastic piece of serendipity as they fit perfectly!
Some of the beams were re-purposed from our formwork, including the open-ventilation roof support on top of the feature wall.
All of the interior doors are salvaged, collected from yard sales, flea markets, roadsides and Habitat for Humanity Restores. I have my eye on one from Legacy Vintage Building Materials in Cobourg to be used between the great room and master suite.
The supports for the deck (and the sink in the powder room) are logs from the trees removed to make the driveway.
To see more photos of the house visit BEC Green’s Facebook page.
For more information about Aerecura Rammed Earth Homes, contact Sylvia Cook at: email@example.com or 289-251-6684.
Visit Aerecura’s website for more information.
I read a lot; It’s the only way to stay somewhat current on what’s happening in the world of green building, and the environment. Below is a list of my favourite articles from this past week.
http://www.buildinggreen.com/live/index.cfm/2011/3/30/Are-Wind-Protestors-Full-of-Hot-Air: Paula Melton talks about the darker side of building large wind farms. In Vermont there is a proposal for 21 wind turbines to be installed along the pristine Long Trail, a hiking trail that eventually feeds into the Appalacian Trail. The Green Mountain Club is a group of volunteers that helps maintain the trail and make sure trail signs are clear. Now they’re working with the Wind Turbine company to ensure they do as little environmental damage as possible — which, it turns out can be fairly significant when you’re installing 21 wind turbines.
http://inhabitat.com/mit-scientists-create-artificial-solar-leaf-that-can-power-homes/: Over at Inhabitat, Lori Zimmer talks about the development of a new type of solar energy system that Dr. David Nocera of MIT has just developed. The size of a playing card, it can produce enough energy to power a single house for a continuous 45 hours. This little gem is apparently now ready for mass commercial production and could be a huge boon for homes in third world countries with no access to power.
Over at Building Green again, Brent Erlich highlights some of the latest green building products for your new kitchen including cork flooring, super-efficient appliances from Bosch, and the latest “hot” gadget in the world of water efficiency, the foot pedal for your kitchen faucet. Great tip, faucet aerators in the kitchen aren’t so great if you have to wait five minutes for a stock pot to fill. (Update: article no longer available on the web. August 23, 2012).
http://inhabitat.com/5-tips-to-green-your-living-space-from-zem-joaquin/: Ecofabulous founder, Zem Joaquin, has an interview with Inhabitat columnist, Jill Fehrenbacher about the little things you can do around your home to make it greener. Not only are her tips practical, she also suggests specific products that you can use the next time you do a renovation.
The New Normal: An Agenda for Responsible Living, by Dave Wann. His book calls for a paradigm shift about how we view “success” in life, and look at it in ways other than consumption, because at the rate we’re going, we’re outconsuming our future.
At Practically Green, Sam Roach interviews Allison Goodwin who works for Chelsea Green, a publishing company which, for the past 27 years, has been publishing books on “the politics and practice of sustainable living.”
http://www.jetsongreen.com/2011/03/first-passive-house-north-carolina.html: Preston over at Jetson Green has written about, (and included pictures!) of the first passive house in North Carolina. There are some great specifics in the article about the HVAC system, the type of windows used, and some energy saving appliances installed.