SUSTAINABLE design is the foundation of green architecture and is a broad-scope subject that will become more and more prevalent in residential architecture in years to come.
Municipalities are beginning to recognize that sustainable design practices can make a real difference on a city's greenhouse gas emissions and are starting to create building policies to reflect this.
In 2009 the City of Vancouver initiated its Greenest City 2020 Action Plan to become the greenest city in the world by the year 2020. An essential part of this action plan was the setting of mandatory targets in its building policies for new homes. In Vancouver family homes occupy three-quarters of the city's residential land and produce one-fifth of its greenhouse gas emissions.
To counter the trend the City developed its Green Homes Program laying out realistic and achievable goals that would help homeowners save both energy and water while allowing them to move towards a smaller carbon footprint.
Understanding the requirements of the City of Vancouver's Green Homes Program can help us all in our own green building choices. Here is a list of the current requirements for new one and two family homes as outlined in the program: 1. All new homes must be made adaptable to future energy generation technologies as they become available. Simply stated this means that a new home will be required to have two 50-millimetre pipes running from the mechanical room - or the location of the hot water tank - to the attic in order to allow for the future installation of roof mounted solar energy generating systems.
2. The City of Vancouver requires all new homes to run a cable raceway from the home's electric panel to the garage in order to facilitate the installation of a future electric-vehicle charging system.
3. Exterior above-grade walls need to meet a higher insulation standard than before. This can be achieved by using 2x6 wood construction, in-filled with high-density batt insulation.
4. Energy efficient lighting utilizing compact fluorescents or light-emitting diodes must be used in locations such as hallways, porches and garages. The use of these energy efficient light bulbs is a simple way to reduce energy consumption.
5. High-efficiency single flush toilets or approved dual-flush toilets must be used in all new homes. It's simple logic. There's no point in flushing perfectly good water down the toilet.
6. All windows need to meet more stringent energy performance requirements. Windows with the EnergyStarTM label meet these new energy efficiency requirements.
7. Full height basement walls must meet the same insulation requirements as above-grade exterior walls. The idea here is to make these spaces more livable and less of an overall energy drain.
8. Concrete slabs, be it in the basement or at grade, need to have a minimum of R12 insulation underneath them to ensure a minimal heat loss through the floor.
9. Gas fireplaces are typically inefficient heaters and can actually lose heat when not being used. The Green Homes Program has focused on increasing the efficiency of gas fireplaces by requiring them to have electronic-ignition and to be direct-vented.
10. New homes are becoming more and more air-tight - a good thing as this prevents heat loss but, as a result, requires a constant supply of fresh air. Heat Recovery Ventilators draw fresh air from the outside while exhausting out stale inside air. The HRV allows the heat from the inside air to be transferred to the cooler incoming outside air with little heat loss, creating a simple and efficient system that reduces heating requirements. Heat Recovery Ventilators are mandated as part of the new program.
11. Since hot water tanks can be terrible energy wasters, all new electric hot water tanks and their pipes need to be wrapped in insulation to reduce heat loss.
12. As part of the Green Homes Program all new homes need to install an indoor electricity usage display meter. This clever device tracks your energy usage and lets you know exactly how much power you use for various actions. If you forget to turn off a number of lights you'll see exactly how much energy you lost. I can't imagine a simpler way to encourage some energy-saving habit changes.
Kevin Vallely is a residential designer in North Vancouver. Follow along Kevin's "small house" design at cliffhangerhouse.com.