The term “green home” means different things to different people. Some only consider a home green if it lives up to the highest LEED standard, whereas others are less interested in the formalities of certification. In general, however, a green home uses less energy and is built with sustainable building materials that have lower embodied energy than a conventional home. Here are some of their common characteristics:
Construction and demolition waste constitutes more than one-quarter of the United States’ total non-industrial waste (Source: EPA). Big, bulky building materials place a heavy burden on the environment because of their high-embodied energy and massive carbon footprint.
Green builders see the folly of their conventional counterparts and seek to change the way homes are built. They try to reduce materials wherever possible, and for the materials they do use, they tend towards products that have the following attributes:
- locally sourced
- made using renewable energy
- composed of rapidly renewable resources
- contain as little embodied energy as possible
So, to the green builder, a wooden window frame made from local wood is preferable over aluminum frames that were built in a fossil-fuel powered factory and shipped a great distance. And using locally available earth to build a home makes more sense than using bricks and wood. Similarly, using rapidly renewable bamboo would be favoured over tiles.
According to the 2011 Human Activity and the Environment report, Canadian households accounted for 45 percent of Canada’s total greenhouse gas emissions. (Source: Statistics Canada).
Since homes place such a high demand on municipal electricity and water utilities, green homeowners try to alleviate this massive use of energy by installing energy-efficient renewable energy systems, such as solar panels and ENERGY STAR appliances.
But energy efficiency alone does not make a home sustainable. Someone could build a massive net-zero energy home using concrete, steel and bricks on environmentally sensitive land, making it inherently unsustainable.
Size and design
As mentioned in the previous example, for a home to be sustainable thought has to go into what it’s made from and how it’s made, not just how it operates. Similarly, the larger the home the less sustainable it is because it inherently has a larger physical footprint and higher embodied energy. It would be really hard for 5000 sq. ft. home, even with all the latest renewable energy systems, to be more sustainable than a 1500 sq. ft. home, for example.
Passive solar / passive houses are sustainable building designs that don’t require any special systems to be energy efficient since they already are energy efficient by design. Smart design is akin to solving a problem at its root. Building intelligently up from the roots makes for a sound structure.
Green homes are often built on already developed land to reduce their environmental impact. Sprawl is inherently unsustainable because it chews up green space. There’s nothing “green” about that. Green homes are also commonly built in close proximity to community resources to minimize homeowners’ transportation demands.
Since Americans spend an average of 90 percent of their time indoors (Source: EPA), indoor air quality (which is often worse than outdoor air quality) is a major concern, particularly to those with environmental sensitivities. Green homes give occupants greater control over their indoor environment and promote better ventilation, lighting and comfort. Designers use furniture, paints and other household products that emit little or no volatile organic compounds (VOC)—chemicals that are harmful when inhaled.
The concept of “cradle to grave” life cycle assessments have gained popularity in recent years because people are demanding to know the full picture, the true story of a product so they can wring the greenwash out of it. Green homes are no different. Since homes all have a lifespan, it’s important to think about what will happen to the materials when they’re done. Just as green homes use reused or recycled materials, how reusable or recyclable will the materials be for future generations.
image: Photo Dean