By Sarah Lozanova
Greater energy independence, freedom from fluctuating energy prices, and environmentally friendly living are alluring concepts that motivated my family to examine our housing and our lifestyle. We recently purchased a high-performance home and installed a solar system, making our home net-zero. We now produce as much power as we use over the course of a year.
Realizing the Dream of a Net-Zero HomeTo realize the dream of a net-zero home, we bought a superefficient home atBelfast Cohousing & Ecovillage, a 36-unit multigenerational community in Midcoast Maine with triple-pane windows and doors, virtually airtight construction, a solar orientation and lots of insulation. The sun, appliances and occupants provide a majority of the heat needed to keep our home cozy.
On sunny winter days, our heaters remain off, as the sun gradually warms the house. Electric baseboard heaters kick on as needed, primarily at night or on cold, cloudy days. The home is all electric—with an electric range, hot water heaters and space heaters. Because we don’t use propane, natural gas or heating oil, a solar system can produce all the energy that our home consumes.
This 36-unit community may be the nation's first planned development built around Passive House green building standards.
By Sarah Lozanova
Even from the layout of the homes, visitors can tell something is unique about Belfast Cohousing & Ecovillage. “Where are the driveways?” one guest asks. “How strange, these houses don’t have any driveways!”
Belfast Cohousing & Ecovillage (BCE) is a 36-unit intentional community on 42 acres in Midcoast Maine. Members designed the community from 2008 to 2011, before breaking ground in 2011; GO Logic, a Belfast-based design-build firm that specializes in sustainable building, designed the units and site plan and served as general contractor.
The homes are clustered, and a pedestrian path, not a road, runs through the six-and-a-half-acre built area. Despite being a rural property, all the homes are located in two- to four-unit buildings and range from 500 to 1,800 square feet with one to three bedrooms. The community layout encourages social interaction, offers safety for children, and provides open space for food production, wildlife and recreation. With PV solar systems, these highly efficient homes are near net zero.
PASSIVE HOUSE DESIGNS
When one enters the homes, it becomes obvious that the lack of driveways is only one of many differences between these houses and the average code-built home. Despite being located in Midcoast Maine, the houses have no furnaces.
By Sarah Lozanova
Inspired by the concept of making a sustainable lifestyle easier, GreenPod creates low-maintenance modular homes with healthy interiors.
Factory-built kits can be transported to a building site and easily assembled. Using state-of-the-art technology and materials, these homes have a small footprint and conserve both water and energy. The homes, including tree houses and floating homes, are customized to the site, have passive solar features and minimize site disturbance.
The walls, floor and roof of the homes use SIPs (Structurally Insulated Panels), with a rain shield on the exterior. “The homes are precut when they come out of the factory, so they can go up in a day or two on the site,” says Ann Raab, GreenPod’s founder. “SIPs are the best bang for your buck. Although they are slightly more expensive than a stick built home, SIPS have a short 2.7-year payback. They are stronger and straighter than wood, with no job waste [because the SIPs are precut]. Everything about SIPs delivers what we are trying to create.”
Raab has a vision to simplify green building, while making sustainable living affordable for the mainstream. GreenPod homes are customized to fit a variety of budgets, with optional features including: locally-crated furniture containing organic textiles, reclaimed building materials, solar panels and a biofilter refrigerator.
By Sarah Lozanova
Our homes can be comfortable and energy-efficient: Especially if we borrow from the high-performing, effective ideas used around the world in “passive houses.” Developed by the German Passivhaus Institut in 1996, a Passivhaus is defined by core efficiency standards. What does this mean in practice? Homes built to the Passive House standard are extremely comfortable to live in—with natural daylighting, even temperatures throughout and virtually no drafts.
Passive homes require 90 percent less energy to heat because energy losses are minimized with generous amounts of insulation and air sealing. The homes are heated largely by solar heat gains and internal gains from people and electrical equipment. Although fully retrofitting a home to the passive house standard is usually very costly, we can use many of the elements of passive home design to make our homes more efficient. Apply the following concepts to your home to boost comfort and reduce energy bills.
Boost Winter Solar GainSouth-facing windows and, to a lesser extent, east- and west-facing windows help gradually warm our homes with solar energy. Maximizing this free energy source reduces dependence on heating systems, in turn lowering utility bills in cold climates and promoting indoor air quality. Forced air heating, for example, can carry dust with the heat as it passes through duct work, while wood-burning stoves and heating systems that use natural gas or propane can emit carbon monoxide. Wood-burning stoves also can produce breathable pollutants such as smoke and ash.
Clean southern windows and remove screens. When the heating season begins, remove screens on south- and east-facing windows and wash the windows to increase your solar gains by up to 40 percent. Keep screens in the west- and north-facing windows to provide protection from the winter wind.
Avoid shading southern windows in the winter. Evergreen vegetation, carports and porches can shade southern windows, hindering solar gains. In colder climates, plant only deciduous trees and shrubs (which lose their leaves in winter) outside south-facing windows, or space vegetation and structures far enough away from the house to avoid shading southern windows.
Expand with a solar addition. If you are planning an addition on your home, consider adding a sunroom, which can help heat your home. Effective sunrooms face south, include lots of thermal mass, are thoroughly insulated, and include ventilation options with windows, doors and skylights.
Freelance energy efficiency and renewable energy copywriter