A LEED Platinum home project overview

As building rating systems drive building codes to greater levels of performance, the rating systems themselves need a periodic upgrade to stay ahead of the curve; enter LEED version 4 (V4.) This latest version of the LEED rating system involved a comprehensive overhaul and to ensure relevancy and adoption LEED v4 was reviewed and broken down into positives and negatives by technical advisory groups.

When the Canada Green Building Council (CaGBC) anounced that the LEED for Homes rating system would raise the bar with the LEED V4 program, we at Ecohome were already mulling over the idea of building a showcase green performance home as a teaching tool, and  decided to give the new LEED V4 a test drive. 

We were already planning on building an ecologically responsible, super-efficient, passively-heated house, so we reckoned that much of the LEED program requirements would be happening anyway in this build.  But it was interesting how the new LEED V4 approach involved more integrative processes.

This required all team members to be actively involved during the project, allowing them to work together to discover unique ways to reduce costs, material usage and to minimize the environmental impact of the home itself, and that of the occupants in living in the home in their habits, needs and lifestyle.

For example, one new aspect was to include a credit category for Location & Transportation, placing more emphasis and attention on reducing main contributors to global warming: transportation. The Location & Transportation category includes strategies to reduce costs, pollution and resource depletion related to daily commutes.  So the Ecohome team decided early on to reduce the energy consumption of the home to a minimum while providing electric vehicle charging as an integral part of the energy use calculations.

We were pleased to get the confirmation that the Edelweiss House in Wakefield, QC received final certification of Platinum under the LEED V4 for Homes program, the first project and home in Canada to do so. Not only that, the Edelweiss House was only the second LEED V4 Platinum home certified worldwide - a result we are proud of and which prompted Thomas Mueller, President and CEO of the CaGBC to comment:

“The Edelweiss House is a phenomenal achievement - the first Canadian project to meet the stringent requirements of the latest version of LEED at its highest level, I commend Ecohome for being a leader in the Canadian home building community and for demonstrating to the industry that high sustainability standards can be achieved right here in Canada, right now.” 

What is the cost of a LEED Platinum home?

The final Edelweiss 1552 sq.ft. house was built for only $300,000 Canadian in 2015, about $221,000 USD at current exchange rates), or $193 per sq. ft. (about $143 USD per sq.ft.) which is exceptional for such a high specification home. However this did include some unbilled time from the owner, who paid particular attention to such aspects as air sealing details which take time.

This build included a long list of environmentally friendly materials, specifically chosen to ensure a healthy internal air quality for the home, and includes mechanical systems with not one but three interwoven and efficient options for heating

Some of the Eco-friendly features in the Edelweiss LEED V4 Platinum home (included in the build cost) :

First performance benchmark for Edelweiss: Passive Solar Index 15

Registration date: August 25, 2015
Region: Outaouais, Quebec
Type of construction: Single-family New home
PSI rating: 15 kWh / m²
Method of calculation: measured post-occupancy

One of Edelweiss's most impressive attributes is its extremely low energy demands and operating costs. Energy-modeling software predicts that the house will use an average of 24.6kwh of electricity per day, or an average over the year of $1.39 (Canadian) per day based on current electricity rates from Quebec Hydro. For a full year, heating, cooling, and interior plug loads should add up to about $507 ($385 USD)

Even if the owners drove the 33 km to Ottawa every day for work in an electric vehicle, using the incorporated charging station at the house, that would bring total energy consumption to about $2.30 per day ($1.75 USD).

The Edelweiss House was designed and built by two founders of Ecohome, Emmanuel Cosgrove and Mike Reynolds, and as Reynolds puts it: "with some thought put towards costs savings in design, you don’t have to blow the bank to build a high-performance house. That’s what this project was really about, to show that super efficient homes can be built on a reasonable budget”.

First and foremost, Reynolds said, is the passive design of the house. “The primary heat source is the sun,” he said. “The majority of the heating requirement is met by the windows. So really, our primary heat source would be passive solar heat gain.

The team also took advantage of deciduous trees on the south facing side of the building lot to effectively shield the windows from any possibility of overheating in summer, while allowing the lower winter sun to stream into the main living area and heat the thermal mass of the concrete floor. To ensure happy feet, there is also a hydronic radiant-floor heating system paired with an electric boiler with carefully controlled backup heating control system too.

Exterior wall assemblies for this beautiful LEED platinum home include:


8 in. of semi-rigid mineral-wool insulation on the outside of the sheathing, and another 5-1/2 in. of mineral-wool batts in stud cavities packaged in a high-performance building envelope. Exterior walls of the slab-on-grade house have a total of 13-1/2 in. of mineral wool (5-1/2-in. batts followed by 8 in. of semi-rigid insulation) for a total R-value of 58. See here for full details of this LEED home's super-insulated wall design.

There is R-32 worth of mineral wool under the slab, and R-95 of mineral wool in the ceiling under the green roof. 

Air sealing:

Edelweiss incorporated very careful attention to detail in air sealing the building envelope, and were able to achieve the very high Passive House airtightness standards

Canada's first LEED platinum V4 certified home - The Edelweiss House © Ecohome

Which renewable energy system was chosen?

Photovoltaic solar panel systems are often used to offset building energy requirements on high-performance or Net Zero Energy homes, especially as the cost of solar panels continues to fall. But for the LEED certified Edelweiss project, Ecohome didn’t think they would contribute sufficiently to offset their initial investment or the additional carbon footprint.

You can get so much more if you invest first in efficiency,” says Reynolds. “There are a lot of houses that are going Net Zero Energy simply by popping on solar panels on top. But we wanted to bring it down to the basics and just show how little energy a house needs to use in the first place. Yes, we could have installed solar panels on top of it, but power in this region is all renewable hydro, not coal or another fossil fuels. so really the greenest power we could get was right from the hydro pole".

Why choose LEED Certification instead of Passive House? 

Ecohome also decided for LEED certification instead of Passive House certification because even though the Edelweiss House’s energy consumption for heat and its level of airtightness are at or near the required levels. “We met the Passive House heat requirement and had virtually the same on air changes. Passive House is a great initiative, but the targets don’t reflect a Canadian climate on the whole, and LEED is a far more encompassing system that also includes the idea of a healthy home in it's choice of building materials".

Which is Canada's greenest home? Is it the Eidelweiss project? 

With a heating requirement equal to that of Passive House, top points for energy efficiency of LEED V4 platinum, a slew of recycled materials, we'd like to think the Edelweiss House would be a main contender. But we acknowledge it's really hard to say; there are so many variables and criteria to consider.

Eidelweiss is a simply designed yet elegant Scandanavian feel, passively heated slab-on-grade rancher capable of housing a family of 4 comfortably in a sustainably sized home. And best of all, it was done well within a conventional building budget. 

The premise of the Edelweiss House was to focus primarily on extreme performance, durability, healthy air quality and above all - affordability. Performance homes don't have to blow the budget and affordable houses don't have to be energy hogs. The energy savings in the Edelweiss house are so extreme that it would be considerably cheaper to buy and live in this house rather than a house built simply to meet the base requirements of building code - just about anywhere in North America. 

The Edelweiss House is in Quebec, so it does benefit from lower than average power rates but then the climate is also potentially more extreme, so homeowners in other parts of North America should not immediately write-off the idea of heating a house like this with electricity based on high daytime rates.

As a  house such as this requires very little heat to begin with, its passive heating by design and ability to retain heat by a combination of thermal mass and high performance insulation and building envelope design would make it very easy to limit any heating to off-peak hours if preferred. 

“The biggest message we’re after is not to look at the building-code base requirement as a target to achieve and then just resign yourself to spending tons of money every month to pump heat into your house,” Reynolds said. “Instead, invest that in insulation and the payback is immediate. People tend to think the payback is going to be 20 years away, and it’s not. The payback starts when your neighbor turns on the heat and you don’t.”

For more information on this outstanding LEED Platinum V4 home and its construction, see the Ecohome Building Guide, or these pages:

Find more about green home construction and reap the benefits of a free Ecohome Network Membership here.

If you would like to try a LEED Platinum V4 home before deciding to build one, and you'd like to visit this beautiful region of Quebec, then you can rent the Edelweiss LEED certified home here

LEED Platinum Edelweiss House
This LEED Platinum home is warm & inviting with cork floor, reclaimed wood ceiling & zero-VOC Kitchen © Ecohome
LEED Platinum Edelweiss House
The reclaimed wood doors give the Edelweiss LEED platinum home extra points and some added charm © Ecohome
LEED Platinum Edelweiss House
Rooms are flooded with light with carefully placed windows © Ecohome
LEED Platinum Edelweiss House
Local slate was used for the bathroom floor & walls, as were low flow eco-friendly taps & toilet © Ecohome