Join us for an open house at Canada’s Greenest Home on Sunday, May 26 from 1-4pm!
Explore all the features of the home, talk to the builders and ask “Why?” and “How?”
Explore all the features of the home, talk to the builders and ask “Why?” and “How?”
Canada’s Greenest Home is about to go on the market, and as we switch out of construction mode and into the process of selling the home on its merits we figured this is a good time to reflect on whether or not we’ve met our goals.
Not a Competition
We were initially quite hesitant to brand this project as “Canada’s Greenest.” The claim was not made to be boastful or to dismiss the work of other designers and builders who have made remarkably green homes. The sustainable building community is very “open source” and cooperative, and definitely not competitive. But we were very interested in pushing as many boundaries as possible with this project, to challenge ourselves as designers and builders to make the very best house possible, going beyond what has been done previously.
We had a very well defined set of goals going into this project, and the sum of these goals, we felt, would result in the greenest home in the country. Here is our self-graded report card:
Extremely high energy efficiency
Extremely high indoor air quality
All materials manufactured and sourced as locally as possible
Very low embodied energy materials
Very low water use, with the potential to be water self-sufficient
No sewage output
Zero fossil fuel usage
Very low construction waste
Make a Reproducible Home
Make a Home with “Street Appeal”
High educational value
Prove that the market will support green building
Guidelines and Criteria
We used two green building rating programs to help guide us. LEED for Homes offers mainstream builders an excellent tool for measuring their environmental performance and reaching for higher targets. We aimed to exceed the requirements to meet the LEED Platinum standard, and are well on our way to being certified with a points score well in excess of the Platinum requirements.
The Living Building Challenge is the most stringent construction standard we were able to find, and within its guidelines we found plenty of inspiration. In following the Living Building Challenge we definitely stretched our abilities and understanding and elevated our practice. Certification under the LBC can only happen after one year of occupation, so it will be up to the homeowners to continue to meet the challenge.
No Prescribed Solutions
Despite following two great standards, there is no one-size-fits-all solution to building green. We deviated from some recommendations and requirements of both programs in order to pursue solutions we felt were more appropriate for this project.
We Think We Did It!
There is no reward or prize at the end of a process like this beyond the satisfaction of achieving a professional pinnacle and meeting one’s own very high standards. We anxiously await the buyer who will recognize this achievement and work with us to commission the home in a way that ensures it meets its substantial promise.
As designers and builders, we have learned a tremendous amount from this project, and look forward to applying those lessons to future builds. We also look forward to the day when a home like this is the norm, rather than far exceeding the norms. This type of home building on a large scale would have significant and measurable positive impacts on our environment.
In the province of Ontario in 2002, “1.2 million tones of solid waste were generated from the construction and demolition sector” (Development of Construction and Demolition Waste Recycling in Ontario). A typical home construction project will generate about 8,000 pounds of solid waste per 2,000 square foot home according to the National Association of Home Builders.
The Canada’s Greenest Home project is attempting to seriously limit the amount of material sent to landfill from our construction site. Reuse, recycling and diversion are taken very seriously on this project. To date, we’ve only sent 852 pounds of waste to landfill, and have diverted 3537 pounds to reuse, recycling or other end uses. That is about 10% of the provincial average!
We’ve managed to reduce overall waste to the point where our largest quantity of material going to landfill is floor sweepings! Each time we sweep up inside the building, we pull out any fasteners or recyclable materials before bagging up what’s left. But that dust and debris can weigh a lot, especially after sanding the drywall taping. Our most recent trip to the landfill included 146 pounds of waste, most of which was accumulated floor sweepings. Sawdust, dirt and dust can really add up! We could conceivably bury this material on site, as it’s quite inert. But we wanted to keep an accurate measure of what we “produced” that couldn’t otherwise be reused or recycled.
With landfill tipping costs still artificially low (that is, taxpayers subsidize landfill costs for builders), there is little incentive to reduce job site waste. If municipal governments were to charge appropriately for access to landfill, builders would save money by diverting waste to other streams. In the meantime, it’s not difficult to achieve the significant reductions we’ve managed on this project. Placing appropriate bins on site and labelling them well is the biggest step, followed by designating someone on site to manage waste. Buy-in from subcontractors is important too.
Even minimal improvements on conventional building sites could seriously reduce landfill use. We hope this project sets a high bar for what is possible when it comes to construction waste management.
Natural clay finish plasters add an unparalleled beauty to any home, and it was exciting to apply these plasters to Canada’s Greenest Home this weekend.
These skim coat plasters can be applied over any wall surface. In this project, we used them over clay base coat plasters and over drywall.
The plasters are mixed on site using widely available and affordable materials. Clay, sand, calcium carbonate, pigment, flour paste and water are mixed together and applied to the wall by trowel in a single, thin coat (~1/8 inch).
Our typical formula is 10 parts clay, 4 parts sifted sand, 1 part calcium carbonate, 1 part flour paste (a natural glue/hardener) and ~3.5 parts water. Natural pigments are added to this mix by weight, based on trial samples made in advance. As with baking, the dry ingredients are mixed together and then added into the water, flour paster and pigment that have been blended.
The clay in this case is Tile 6 Kaolin, from a pottery supply store. We’ve used other kaolins and ball clays with similar results. Calcium carbonate is finely ground limestone, from Omya in Perth, Ontario. Flour paste is cooked by boiling 4 parts water and adding a mixture of 2 parts cold water and 1 part flour and boiling until thick. Our natural pigments come from Kama Pigments.
There is nothing like the depth, richness of colour, sound attenuation and warmth of a natural clay finish plaster!
One of the great difficulties of building a sustainable home is figuring out what products are really “green” and which are just greenwashed versions of less-than-sustainable products.
The hardwood flooring we’ve installed at Canada’s Greenest Home comes from The Nadurra Wood Corporation in Toronto, and Nadurra is one of those companies that we know we can trust to sell only products that meet the highest standards. The company was formed by people with long involvement with sustainable forestry initiatives, and they take an active interest in ensuring that all their products come from well-managed forests.
Their line of hardwood flooring is certified by the Forest Stewardship Council (FSC), the most widely respected third party certification in the world. Their hardwood collection is also harvested regionally, with forests in the northeastern US, Ontario and Quebec.
The finish on the floor is a factory-applied, UV-cured urethane that is VOC-free.
We chose a “rustic grade” of maple in natural colour (no stain). This grade makes use of wood that would not normally be chosen for flooring due to variation in colour and the presence of some knots. This ensures that more of the available wood from the tree is used, and brings a natural variation and beauty to the floor.
The installation of the flooring is the first step in the final finishing of the home’s interior.
The Clivus Multrum composting toilet is one of the most important systems in Canada’s Greenest Home, and company representative Don Mills came up to Peterborough recently to help us with the fine points of the installation.
As mentioned in a previous post, treating human “waste” as a valuable and important resource instead of allowing it to become a sewage problem is an important step in the move toward more sustainable housing.
Now that our composting toilets are ready to be commissioned, it’s a good time to look at how this particular system works, and why we chose this type of toilet system over others.
There are three basic categories of indoor composting toilets. The first – and by far most simple and affordable – is the bucket toilet. We at Endeavour love the bucket toilet, and recommend it highly for its low cost and effectiveness, but it was not a choice for a spec home! A step up from the bucket toilet (in price and acceptability, if not performance) is the self-contained composter. These toilets feature toilet and compost tray together in one unit. These can be effective in situations where usage is light, but do not have the capacity to handle the daily use of a whole household. In order to try to “speed up” the composting process in these systems, heat is often used to evaporate urine and accelerate the decomposition of the solids. But by getting rid of the urine and making the solids dry and warm, a great deal of the valuable nutrients are wasted.
The final type of composter is the remote chamber style. These toilets have a large storage bin able to accept input from multiple toilets. The Clivus Multrum system is designed to make sure that composting takes place in the best possible environment, resulting in the recycling of the maximum amount of nutrient value.
The main tank for the Clivus Multrum system features a sloped base, with fresh deposits entering at the rear end of the tank and pushing older material forward. Once the system is established, there is a large bed of material in the tank. It is a mixture of solids, toilet paper and wood shavings. In this way, the Clivus system is like many others.
Two aspects really set the Clivus Multrum apart. First, the system captures all of the liquid and makes it accessible as a fertilizer. The urine that is collected has percolated through the composting bed, providing benefits to the solid compost as it passes through and changing in chemistry (to nitrites and nitrates) to become an excellent fertilizer with none of the potentially damaging effects of straight urine. This liquid is collected at the front of the tank and pumped into a separate holding tank. From here, it can be applied directly to gardens and lawns.
The vast majority of valuable nutrients that can be retrieved from human waste are found here, according to Don Mills. Simply diverting and/or evaporating urine is to waste a valuable resource.
The second unique feature of the Clivus toilet is the moistening system. The tank includes a sprayer and controls that mist the compost pile regularly with a small amount of water. This provides the ideal conditions for effective composting: not wet, not dry, but consistently moist. Having provided sufficient nutrients, aeration and moisture, the rich colonies of bacteria, protozoa, rotifers, actinomycetes, fungi, mold, yeast and earthworms can best go to work converting solid waste to useful compost. Dry compost material needs to be removed from the tank about once a year.
When fully functional, the toilet will require monthly attention, to mix in wood shavings. The liquid fertilizer can be pumped directly to gardens or transferred to containers to take it elsewhere.
In an upcoming post, we’ll look at the unique foam flush toilets that are the other unique feature of this system.
One of the most important features of Canada’s Greenest Home will be the use of nothing but non-toxic finishes for every surface in the home. Many of these will be home-made from natural ingredients. These non-toxic finishes will go a long way in ensuring that the home has a high level of indoor air quality, rather than the polluted air of most conventional new homes.
Natural finishes are an exciting part of this project because they are the most easily reproducible sustainable building element that a homeowner can apply to any new housing or renovation project. We hope the ideas and recipes we’ll post here will encourage more people to use natural finishes.
The whitewash we have used on the pine ceilings on the main floor of this home are a great example of a natural finish that is simple to make, non-toxic, durable and beautiful. Whitewashes have been used for centuries on wood and masonry surfaces, and bring a clean brightness to a room without affecting the moisture storage capability of the material or introducing any VOCs or petrochemicals to the building.
The whitewash recipe we used to achieve a semi-opaque whitewash on bare pine wood is:
1 part Casein powder
12 parts water
16 parts powdered hydrated lime
The water and casein were mixed 2-12 hours in advance and allowed to sit. The lime powder is then slowly added while stirring in a bucket with a drill mixer. The mixture will have some tendency to settle, and should be stirred frequently during application to ensure an even opacity. 1 gallon covers approximately 500-750 square feet per coat. We apply two coats to ensure an even coloration.
The amount of water can be varied to make a thinner or thicker paint, and pigment can be added to give tints. Without pigment, the colour is a bright white.
If powdered casein can’t be obtained easily, a similar recipe that will give good results can be made by mixing:
1 cup skim milk
90-120 grams of powdered hydrated lime
A good quality whitewash brush or thick paint brush with natural bristles will do the best job for applying this paint. On flat surfaces a roller could be used, but our V-groove ceiling required a brush to get into all the grooves.
This paint works so well because the casein molecule contains a powerful glue that is released when it reacts with the base nature of the lime, cracking open the casein molecule and allowing the glue to become a binder that securely bonds to the wood and the lime.
More natural finishes will follow!…
The Sierra Legal Defense Fund’s Sewage Report Card for Canada says “Over one trillion liters of primary or untreated sewage is collectively dumped into our waters every year by cities evaluated in this report (of 21 Canadian cities). This volume would cover the entire 7800 kilometer length of the TransCanada Highway to a depth of nearly 20 meters – six stories high.”
With this in mind (and remembering that this statistic is only counting large cities, not smaller cities, towns and individual homes), it is not possible to think about building a so-called “green” home if that home is contributing to this huge environmental problem.
However, unlike many other environmental issues that are complicated and difficult to address, this one can be handled quite simply: We need to compost our own human excrement. The process is not difficult, and there are solutions that range from the simple and inexpensive (see The Humanure Handbook for the $20 solution) to the more expensive – but still remarkably simple and affordable – chamber-style composting toilet as installed in our Canada’s Greenest Home project.
We started the installation of our Clivus Multrum M10 composting toilet unit today, and we’ll cover that installation in more detail as it progresses. But this is not just a “flashy” green addition to the home… we consider this one of the most important features of the home. Not only does it remove this home’s black waste from the atrocious statistic above, but proper composting of human waste creates useful and nutrient-rich soil amendment. At a time when we can ill afford to pollute more fresh water and when soil depletion is a real and growing problem, the composting of human waste provides a win-win solution.
When asked at workshops and public presentations what the one biggest “green” improvement somebody can make to their home, my response is always to move to composting toilets. It’s not a popular answer. We don’t like to think about our own excrement, let alone contemplate dealing with it.
But it’s not as yucky as most people would think. Dealing with a dog’s waste with your hand in a plastic bag is much more visceral and disturbing than dealing with a well-managed composting toilet system, and millions of people have been “trained” to pick up after their dogs. With that in mind, it’s not hard to imagine a future in which turning our own waste into useful compost is socially acceptable and expected.
Those of you following this blog will know that a lot of time and energy has gone into making Canada’s Greenest Home as air tight and energy efficient as possible. And you probably saw our self-congratulatory post about our great blower door results last week.
So imagine our shock and horror when we got to the house this week after the drywall crew had been there to hang board, and saw that they had cut through our air barrier in countless places! And this was after having a talk with the owner of the company stressing the importance of air tightness in the project and receiving his assurance that his crew were aware of this and would be careful!
It doesn’t really matter how well designed a building might be, how much attention each person on the crew puts into their work… if one trade on site is not committed to the idea and the execution, the building will not meet its goals.
In this case, we found these tears and will peel off the board and repair them. That should bring us back to the air tightness we’d achieved prior to the drywall (especially with the Siga tapes).
But if we had stayed off site until the drywall was done, all of this would have been covered up and we would have been surprised to find our final blower test showing much worse results than our initial test.
Is it any wonder the building industry squashed the proposed regulations that would have required a blower door test by code? There just isn’t enough training about high performance building for the trades and not enough buy-in from the guys on the ground to ensure that buildings will perform as well as they can and should.