Article No: 284

2010-12-09 09:21:17
Sweet Harmony
By: Christopher Brooks

One of the most unique homes using concrete is currently being built in Burnaby, BC, in Canada, with a Net-Zero approach to energy and cost savings.

A Net-Zero energy home is capable of producing, at minimum, an annual output of renewable energy that is equal to the total amount of its annual consumed/purchased energy from energy utilities, said Arthur Lo, president of Insightful Healthy Homes Inc. of Vancouver, which is builder of the home. In addition to its environmental advantages, Net-Zero housing also focuses on occupant health, resource conservation, and overall environmental effect, including ecosystem protection and environmental conservation.

The single-family Harmony House project is one of a dozen Net-Zero energy houses to be constructed across Canada under the Canada Mortgage and Housing Corp. Equilibrium Initiative. Lo said Net-Zero can be achieved using many different techniques including:

Minimizing energy consumption: maximizing building envelope performance, using passive solar energy and daylight, high efficiency lighting fixtures and appliances

Using integrated onsite renewable energy systems: photovoltaic and solar thermal energy, ground/air source heat pumps and mini-wind turbines

Harmony House will demonstrate that it is possible to build a highly energy-efficient building envelope. The home will reflect the housing and work requirements of its owners. It will also contain an in-law apartment in the basement; also an office for a medical practice on the main floor. Locating the office within the home will reduce transportation energy consumption of the household. It is anticipated that an electric car will be used, its power will be provided by the photovoltaic (solar electric) system to be installed on the homes roof.

The second floor contains two smaller bedrooms, a small bathroom and a master bedroom with a master bathroom and walk-in closet. The master bedroom opens onto a south facing deck with a view to water, islands and mountains. High efficiency skylights are used to illuminate both bathrooms and the walk-in closet.

The entire project, from ground breaking to gutter installation, is being documented for a television series on Sustainability Television, said Richard Fearn, president of Fab-Form Industries Ltd. based in Surrey, BC, and manufacturers of the Fastfoot Monopour System used in the project.

It is the first Monopour foundation in the world that had 16-foot elevation changes, which is designed to save the homeowner thousands of dollars, he said.

The reason our system was used is that it greatly reduces the cost of forming the highly insulated foundation. The process requires no stakes, no forming lumber and no stripping of the forms once poured, Fearn said. The end result is greatly minimized lumber and labor costs.

Fearn pointed out there was no labor to interface the ICF block with footing. There is no shimming or pumping up the ICF block to make it level. Supports are adjusted with electric drill to correct height.

One pour was needed for both the footings and the walls, requiring only one pump truck and crew costs, no trowelling of the concrete and no concrete leakage through the forms. Because of these cost savings, there is more money made available for energy producing systems.

The homeowner receives many benefits including improved air quality. The FastFoot acts as a damp-proof membrane around the footing. This prevents moisture wicking up into the concrete footing and eventually into the structure. Fearn added, Finally, structurally speaking, you have a better foundation, as there is no cold joint between the footing and the wall. Concrete is poured in one day, ensuring no void between footing and wall.

This system uses the ICF block itself to form the footing. Supports suspend the ICF blocks above the ground at the required footing height.

Fearn described the six steps to the Monopour system:
Pre-glue six ICF blocks into 12-foot long, two layer high foundation components and attach pairs of side supports.
Layout FastFoot around the perimeter of the foundation.
Install foundation components.
Complete the balance of the foundation wall and brace.
Button-up Fastfoot.
Pour concrete.

Project Designer Chris Mattock, MRAIC, with Principal Habitat Design + Consulting Ltd. in Vancouver said this system, through its multiple efficiencies, saves the homeowner significant money. These savings reduce the substantial capital costs of achieving Net-Zero, for example the photovoltaic cells, he said.

Mattock said in order to reduce annual heating requirements, a highly insulated building envelope is used.

This envelope incorporates R45 insulated concrete forms for the basement and crawlspace walls as well as R20 extruded polystyrene foam insulation beneath the floor slabs, he said. Innovative 2x6 above grade walls will be insulated to R41 and the ceilings will be insulated to R 60. The project will also incorporate a range of other green features that will lower its environmental impact and create a healthy indoor environment for the occupants.

Built with ICFs manufactured by Quad-Lock Building Systems Ltd. in Surrey, the homes basement is partially above ground and has an 8-foot-tall ceiling and generously sized rooms, as well as large windows to provide a spacious feeling. The first course of the basement has been set using Quad-Lock R-45 and the Monopour system. This project needed an ICF with a total wall thickness of 18-1/4-inch to produce an R-value of 45. This insulation level was required to achieve the Net-Zero rating.

Builder Lo said his company Insightful is committed to using the above techniques wherever possible. I believe Harmony House is one of the first Net-Zero homes in British Columbia. Through design and planning that Net-Zero can be a feasible choice for market housing anywhere in the world. We require this R-45 insulation level to achieve our Net-Zero rating.

Based in Bucks County, Penna, contributing writer Christopher Brooks writes about the home " inside and out " for consumer and trade magazines.