Canada’s Greenest Home at 136 1/2 James Street, Peterborough

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.

Our Goals

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

• The annual heating bill for the home, as determined by energy auditor Ross Elliott of Homesol Building Solutions, will be around $325 annually.
• The home will have net zero energy use if the occupants have “average” power usage habits, and the photovoltaic panels will provide an income for the homeowners.
• We achieved a very high degree of air tightness, with the final test showing 0.63 ACH/50 (air changes per hour at a 50 Pascal pressure differential).
• An Energy Recovery Ventilator (ERV) supplies fresh, filtered air with minimal losses of heat and moisture from the building.
• A complete energy monitoring system with central touch-screen display will assist the owners in meeting their own energy consumption targets. A smart phone can monitor the system from anywhere in the world.

Extremely high indoor air quality

• Every finish and surface in the home meets the highest standards for being chemical free and non-toxic. Achieving this level of non-toxicity was a great challenge, and one we’re proud to have met.
• The air handling system has the best filtration system available, and the owner can control fresh air exchange with simple controls.
• Occupants with chemical sensitivities should find the home to be a very welcoming environment.
  

  Living room with south-facing windows and clay plaster walls

All materials manufactured and sourced as locally as possible

• There are many green building products available in other markets (Europe, in particular, leads Canada in this way), but we wanted to avoid importing solutions and meet our targets using only materials from within a 250km radius. For all the major components of the building, we were able to achieve this goal. This keeps transportation energy costs and impacts minimal.
• The market makes achieving this goal very difficult. Outsourcing to less expensive labour markets means that some categories of products are no longer manufactured in Canada, or even in North America.

Very low embodied energy materials

• We chose materials with the lowest possible harvesting and manufacturing impacts. By choosing materials like straw bale walls from NatureBuilt Walls and recycled cellulose instead of petrochemical foam insulation, we are able to greatly reduce environmental impacts to a fraction of a conventionally-built home’s footprint.

Very low water use, with the potential to be water self-sufficient

• The rainwater collection and filtration system is designed to allow the homeowner to be water-independent. Connection to the municipal water service gives the homeowner the choice to use rainwater for all or just selected uses.
• All plumbing fixtures in the home have the lowest possible water usage rates.
• Composting toilets use 0.1 liters per flush, rather than the industry best 4.0 liters per flush.

No sewage output

• A complete composting toilet system is one of the most distinguishing features of this home. By eliminating sewage output, the home dramatically lowers its environmental impacts, and by creating useful compost the toilet actually becomes a generative rather than a destructive feature.
• The foam flush toilets provide the homeowner with a very low maintenance and “normal” toilet experience.
• The home sends its grey water to the municipal waste water system rather than dealing with it on site. This was our one major area of “compromise,” with regulations, cost and practicality leading us to decide that the small amount of relatively clean water output would go to sewer.

Zero fossil fuel usage

• An air source heat pump (ASHP) provides heating and cooling with no fossil fuel use.
• Solar panels provide all of the home’s electricity needs. When the solar power is not available, a contract with Bullfrog Power ensures renewable energy is still meeting the home’s needs.

Very low construction waste

• By choosing low-waste building materials and carefully re-using, re-purposing, sorting and weighing our leftovers, we were able to send only 852 lbs to landfill, versus 10,000 lbs for an average home of the same size!

Make a Reproducible Home

• We did not want this home to be a “one-off” specialty home. Any contractor or homeowner can reproduce the results of this home with materials and products that are off-the-shelf.
• We intentionally did not choose materials or systems that would require skills, sourcing or maintenance that are outside the scope of any builder or homeowner.

Make a Home with “Street Appeal”

• While aesthetics are a highly personal matter, we wanted to create a home that fit into an existing neighbourhood. The exterior is intended to be attractive without being “showy.”
• The interior finishes are intended to bring a natural building slant to contemporary design, mixing clean lines and open spaces with natural materials and surfaces. Retraining and retooling is not required to build a home like this.
  

  Clay paint on a prefabricated straw bale wall

High educational value

• Endeavour Centre students, who will hopefully take what they learned into the marketplace and assist with building more homes like this one, built the home.
• Our construction blog has attempted to document the process of building the home, sharing our experiences, sources and lessons learned.
• Open houses and post-construction documentation will make this home as open source as possible.

Prove that the market will support green building

• The home was funded by a private investor as a “spec home,” with no government grants or other incentives.
• Placing the house on the open market will hopefully show other builders that there is an appetite for homes of this type. We believe that the market is changing and that owners are willing to invest in a home that has very low operating costs and a high degree of resilience, and which makes their health and well being a priority.

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.

Red wall almost finished

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.

Helping us with the mixing and application was our good friend Mike Henry, a plasterer with Camel’s Back Construction. His attention to detail helps bring out the best in the clay plaster.

There is nothing like the depth, richness of colour, sound attenuation and warmth of a natural clay finish plaster!

Join us on Saturday, March 9, 10am – 4pm!

Canada’s Greenest Home nears completion

 

January 16, 2013

Workshop Instructor(s): Don Mills
Clivus Multrum

Workshop Description

If you have ever been curious about how a composting toilet works and whether it might work for you, this is the workshop for you!

Clivus Multrum has been manufacturing composting toilet systems for over 30 years, and the company is widely regarded as a world leader in the field. Instructor Brian Barry works for Clivus Multrum and has many years of experience in the field.

This workshop will give an overview of how a composting toilet system works and how to size a system. The main focus of the workshop will be the installation and commissioning of a large M10 Clivus system in a residential setting at Canada’s Greenest Home in Peterborough. Participants will see how the tank is located and installed, how the system is vented and plumbed, and how the liquid pumping and spraying systems are set up. This system uses unique foam-flush toilets, and participants will see how they function and work within the system. Maintenance and upkeep will also be covered.

This workshop will get you familiar with the concept of composting toilets and give you an excellent insight into how a composting toilet can be integrated into a home

Entry Requirements

Open to all

Fee

$55

Maximum class size: 12

More Trent University students may be able to eat locally-grown produce year-round at The Seasoned Spoon cafe, now that their subterranean earthbag root cellar is nearly complete.

This project is very unique, using local low-impact materials to create a food storage structure that will be able to house a range of vegetables at proper temperature and humidity levels year round, without energy intensive cooling or heating equipment.

Here is a complete set of progress photos, showing the building from start to finish:

Endeavour would like to thank the Seasoned Spoon for the chance to be involved with such a great project. Thanks also to Trent University for accommodating the build.

Tim Krahn of Building Alternatives was the adventurous and participatory structural engineer on the project, and Ben Parkes was the lead builder, with lots of help from Justin McKeiver and lots of volunteers.

We’ll post a final look at the root cellar when it’s all complete.

Among the many challenges involved in meeting the Living Building Challenge standard for Canada’s Greenest Home, one of the biggest was how to heat the home given that the LBC does not accept combustion devices of any kind for any purpose.

The Mitsubishi Zuba heat pump is installed on the exterior of the house.

The heat exchanger and plenum for the interior side of the Zuba.

Our first choice for heating this home was going to be a pellet boiler. Impressed with the efficiency and cost of these systems, we were also aware that a number of local pellet making facilities (including one less than 1km away from the home) meant that our fuel supply could be reliable and entirely based on existing waste biomass in the region.

Once we understood that this combustion option was not feasible (and I’m not sure I agree with the LBC’s reasoning on this point), our focus turned to heat pumps, both ground source and air source. Heat pump technology is a great option, as it is the only heating (and cooling) technology that is more than 100% efficient. With combustion devices, for every unit of fuel input there is slightly less than one unit of heat output (hence the ratings that might state efficiencies in the 90% range). With heat pumps, each unit of energy input (electrical energy, used to drive the pump) there is between 1.5 and 5 units of heat created, meaning that efficiencies can be stated in the 150-500% range.

A heat pump works by circulating a refrigerant with a boiling point that is designed to be in the temperature range expected on the outside of the building. By compressing this gas and forcing it into a gaseous state and then allowing it to return to a liquid state, the refrigerant goes through two phase changes. The heat that is transferred during these phase changes is significant, even though the temperature of the refrigerant is not.

The heat pump cycle explained. The important part to know is that the phase change of the refrigerant releases usable heat, even if the actual temperature of the refrigerant is not “hot”. Image from CMHC

This isn’t magic, and it isn’t even a new technology. Your refrigerator is a heat pump, as is your air conditioner. The premise has been around for decades, but has only recently been applied to heating homes on a large scale in the past decade. The use of heat pumps in cold climates has not been feasible until quite recently, when Mitsubishi introduced their Zuba range of cold climate heat pumps. These units are able to make usable heat at temperatures as low as -30C, making them feasible as the sole heat source for a northern climate home as long as the home is made to be energy efficient.

The heat loss calculation for Canada’s Greenest Home was 22,524 Btuh (British Thermal Units per hour). The Zuba is capable of producing 34,130 Btuh, so it is well within the unit’s capacity to fully heat this home.

As with all heat pumps, the Zuba can run in reverse and be an efficient air conditioning unit in the summertime.

The Zuba has two components. On the exterior of the house there is the heat pump unit. On the interior of the house there is the heat exchanger and the air plenum plus the fan and switchwork for the system. It is connected to conventional ductwork to supply heated air to the whole house.

The Mitsubishi Zuba units are supplied in Ontario by Mitsair. Our system was installed by Crown Heating in Peterborough. Our thanks to both companies for their professional assistance.

The decision to go with an air source heat pump was made largely based on the cost of installation. While a ground source unit offers better efficiencies (especially at colder outdoor temperatures), the cost of installation is quite a bit higher, and the payback on the additional investment is well over a decade. Given our investment in other technologies for this home, we decided in this case that the lower cost of installation and the very good efficiencies for the unit made it the right decision for Canada’s Greenest Home.

Please note:
Bruce King is giving two talks in Toronto. For the public presentation, Architecture After Oil, read more here.

For information on the professional seminar, Engineering Outside the Box, continue reading this page…

Engineering Outside the Box, Friday July 27th

Endeavour is pleased and excited to present a seminar with two of the most influential engineers in the realm of natural and sustainable building… Bruce King and John Straube.

The three-part seminar covers everything a building design professional would want to know about working with traditional and emerging natural building materials. The seminar is eligible for OAA credits.

Don’t miss this opportunity to learn from two of the leading figures in natural building!

You can register here.

You can download the seminar outlines here.

ARIDO & OSBBC members receive 40$ off.
Please contact your organization for more info about discounts.

For student rates please contact Endeavour at 705-868-5328 or email us.

Upward progress on Canada’s Greenest Home was marked by the arrival this week of our prefabricated straw bale wall panels from NatureBuilt Walls. The class had previously traveled to the NatureBuilt facility to assist in the construction of the panels, and it was great to see them arrive!

The 24 panels for the two stories of the home arrive on one truck

We hired a crane to lift the panels from the delivery truck and onto the foundation. The site of the home this year offered some challenges… between low power lines at the front edge of the property and a long, skinny lot and home design, the usual boom truck used to move the panels was unable to do the lift. So it was Peterborough Crane to the rescue!

The crane sets up and awaits the arrival of the prefab wall panels

The placement of the walls went very quickly and smoothly, and showed why this form of straw bale building is so attractive. Within a couple of hours, we had a full compliment of pre-plastered straw bale walls standing on our foundation. There is no other form of sustainable building that brings such a combination of ease and speed of installation with such a simple, naturally- and locally-based form of construction. We will also be building our north wall in the “conventional” site-built manner, which will offer the class a great comparison of the two methods.

A prefab bale wall panel is lifted into place on the foundation

Soon, the second floor will be ready to receive the next round of prefab walls…

This week the Endeavour class spent a day at the facilities of NatureBuilt Wall Systems, where we assisted with the construction of some of the Bio-SIP walls that will be used in Canada’s Greenest Home.

The Bio-SIPs are largely identical to the load-bearing straw bale walls that have been used since the first straw bale buildings were constructed in the late 1800s. But rather than building them by stacking bales vertically and plastering in several coats, they are built in a shop space and plastered while lying horizontally. This greatly reduces the amount of labour time involved and ensures walls of consistent strength and size.

We have chosen to use the Bio-SIPs because they meet so many of the criteria we have for Canada’s Greenest Home:

• Locally harvested materials
• Renewable materials
• Reproducible technology
• High energy efficiency
• Low embodied energy
• No off gassing or toxins
• Affordable

Many straw bale buildings use an extensive wooden framework to create a structure to support a roof so the straw bale and plastering work can be done under protection from weather. The Bio-SIPs use the simplicity and low lumber count of load-bearing walls without the need for excessive wooden framing, capturing the benefits of the load-bearing capacity of straw bale walls.

NatureBuilt takes environmental responsibility seriously, right down to the use of used fryer oil as a release agent in their forms. It was great to be in a workplace where our ethics at Endeavour are so closely matched.

The class got to experience the entire construction process for the panels, including assembling and leveling the wooden frames, selecting and sizing bales, mixing and placing plaster and assembling the bales in the frames. In one short working day, we were able to help build nine of the 24 panels for our project.

The walls will be delivered to our construction site when the first floor framing is ready to receive them.

Our thanks to Ian Weir of NatureBuilt Wall Systems for giving us the opportunity to be part of the production of the Bio-SIPs!

The Endeavour class has completed the foundation for Canada’s Greenest Home. The crawlspace foundation is made with Durisol blocks. Durisol is an insulated concrete form (ICF) that uses waste wood chips in a cement slurry to form large blocks (in this case, 14 inches wide by 12 inches high by 24 inches long) with an integral Roxul insulation insert. These blocks create a wall with an R-28 insulation value.

The blocks are dry stacked in running bond, and are easily cut with a regular circular saw and blade where required. A grid of rebar is placed in the blocks both horizontally and vertically, and the open channels inside the blocks are poured with concrete (in our case, with the highest slag content possible).

The Durisol system uses waste wood chips, slag content in the cement binder and the Roxul insulation is made with recycled steel slag to create the mineral wool insulation. It’s a higher impact foundation than we would typically use, but because we’re providing a conditioned crawlspace for this building, it was the best solution for this application.