April 20, 2014
Filed Under Lake Tahoe Eco-Tips
Truckee and Tahoe are breeding grounds for green building. It’s part of our lifestyle. Healthy living, conservation and low maintenance so we can play more!
Green building sounds complicated, until you read the following article by Geoff Clarke, a South Lake Tahoe green building contractor, and co-owner of Natural Energy Designs.
There are many different ways to design and build a green home.
There are different materials and techniques to choose from, none of which is perfect for every location or structure. No matter who is building your home, what is needed is an awareness of the options available. As homeowners you may want to consider methods and materials that are more energy efficient, stronger, require less maintenance, are more resistant to fire and mold, and are in general, healthier for its occupants than a conventional “stick frame” house.
Home design should be determined by the site. Unlike conventional homes, maximum energy efficiency is connected to room and window placement and room function. The first step is to analyze the property for maximum passive solar gain. Simply by orientating the house on the property to take advantage of any passive solar energy you can drastically reduce the energy consumed for heating and cooling for the life of the home. All modern home designs should take advantage of the sun’s passive heating and combine it with an interior “heat sink”, materials that absorb and store solar energy during the day then radiate the heat back into the house later. Combined with proper insulation, this passive heating will regulate comfortable interior temperatures within a small range no matter the outside temperatures. If your site has good solar access, you might also consider photovoltaic panels to supplement your electrical use.
Once the house site is arranged the next step is to choose the materials for the envelope of the home. There are many choices that provide a much greater R-value (thermal resistance value) than conventional wood framing, R-13. Insulated Concrete Forms-ICF’s are forms made of an insulating material usually foam or recycled wood then filled with concrete providing a thermal resistance value of R30-R50. ICF’s can save up to 50% in heating and cooling costs, they are mold resistant, more fire resistant and stronger than wood framing. With the right finish these homes can achieve a 4 hour fire rating, which is the highest rating possible. Other options available are Structural Insulated Panels-SIP’s, rammed earth, straw bale, concrete block and steel framing. Roofing finishes the envelope. There is several choices in roofing available composed of reclaimed/recycled materials which are long wearing and fire resistant.
The windows are important for light, insulation and fire protection. Double panes are standard, with triple pane offering the best insulation. Vinyl windows may melt in a fire, so make sure they have metal sashes to maintain structural integrity. Low “e” windows help retain heat and keep UV rays out of the house. The siding on the house should be low maintenance, resist fire and be aesthetic, for example; fiber-concrete siding, earth-plaster or stucco. Any attached decks should be made from recyclable materials that are no or low maintenance and also fire resistant.
Inside the house, insulation is the key to the transition from the outdoor elements and should have a minimum rating of R-30 insulation in the walls and R-50 in the ceiling. This way any heat or cooling you create can be kept in the house. Many sustainable insulation choices such as cellulose and soy foam are currently available. By maximizing the insulating potential in the structure the initial and long term costs for heating (and cooling) can be keep very low. The insulation can be covered by conventional drywall or alternatives made of sustainable materials that are also fire resistant. Interior materials from walls and carpets to glues and paints should be no or low VOC (volatile organic compounds) which can off-gas materials that deteriorate indoor air quality.
A great compliment to a well insulated home is hydronic heating. Hydronic floor heat is warm, comfortable and efficient. The efficiency of this system can be further increased by hot water solar panels. Another alternative for heating are heat pumps which draw warm air from underground to aid the heating system. There is also high efficiency, low emission stoves of all types. If your envelope is well insulated, heating will not be one of your biggest costs. To continue this idea, use energy efficient and water saving appliances and fixtures through-out your home.
All of these ideas are easy to implement if they are considered in the early stages of design. Together these alternatives create a home that is aesthetic, structurally sound and equivalent in cost to conventional homes, but healthier inside and requires far less energy to build and maintain.
Geoff Clarke is a licensed contractor and green builder. Geoff and his partner, Carla Zezula, run Natural Energy Designs, Inc. a consulting firm specializing in green, sustainable building. 530-307-0225.