By Sarah Lozanova, Clean Energy Writer
Pliny the Elder was the first to write that home is where the heart is, but many older homes are drafty and have cold floors and uneven temperatures that can chill an environmentally aware heart. Do you remember the nursery rhyme about a cold, old house where even the mouse is cold? The good news for the mouse and anyone else concerned is that there are many weatherization products on the market to make homes more comfortable and energy efficient. Insulation is one of them.
You might think that any insulation product that lasts decades and saves a decent amount of energy would be green. Unfortunately, many of the home insulation products on the market contain potent greenhouse gases or release chemicals, degrading indoor air quality.
Whenever possible, choose insulation products that:
Why Is Home Insulation Important?
Home heating and cooling are responsible for nearly half of all home energy use. Insulation is important because heat flows from warmer to cooler spaces until there isn’t a temperature difference. In the winter, heat flows from heated spaces in homes to unheated attics, basements, garages and the outdoors. In the cooling season, heat flows from outside the home to the interior. Insulation stops the flow of heat.
Image Credit: Ryo Chijiiwa
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 renewable energy writer