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Green Home Vocabulary

Many folks  have been working for many years to improve the quality of the homes we build. You will find many names for similar programs as you start to collect information on what many now call Green Homes. Here is a list of some common vocabulary used to describe these homes.

  • Affordable Housing - should be affordable to buy and maintain (low utilities).
  • Air Tight Homes - Well sealed homes, tested with a blower door. Typical existing homes have more than 5 air changes per hour (ACH) under test conditions. Energy Star homes have to be below 5. Many builders achieve 2 to 3  ACH. Passive Homes have to be less that 0.6. Airtight homes should be mechanically ventilated.
  • Energy Efficient Home - a vague term, used freely by sellers of homes.
  • EnergyStar Home - have to be at least 20 to 30% more efficient than code. To be Energy Star, the home has to be "rated" by a third party - including testing for air tightness. A step in the right direction.
  • Green Building - The practice of 1) improving the efficiency with which buildings and their sites use energy, water and materials, and 2) reducing building impacts on human health and the environment through better siting, design, construction, operation, maintenance and removal – the complete building lifecycle. — The Office of the Federal Environmental Executive
  • Green Homes - the latest general term to describe a home designed to be environmentally friendly, including energy and water efficiency, healthy and more.
  • Model Energy Code -  minimum building requirements, the worst home you can legally build. If your builder claims that they build "energy efficient homes", as they build to the new building code, look for another builder!
  • Passive Homes combine super insulation and air sealing techniques so that the home does not require a conventional heater. This usually means a 90% reduction is heat loss from the home. There are very specific performance requirements for Passive Homes. I consider Passive Homes to be the Holy Grail of low energy homes!
  • Passive Solar Homes designed to take advantage of the position of the sun through the seasons to keep the home comfortable. Orienting most of the windows and the long side of the house toward the winter sun is a classic feature of passive solar homes. They should also include very well insulated walls, overhangs designed to allow winter sun to enter while blocking out summer sun, and thermal mass to moderate temperatures. There are no standards for passive solar homes.
  • Solar Homes a generic term meaning that energy from the sun is being used for something in the home. This could be solar hot water, solar hot air, solar electric or passive solar.
  • Superinsulated (SI) Homes again a generic term that means using much more insulation that required by code. To be considered Superinsulated today, I would say you need to have at least R-40 walls and R-60 ceilings. Building this way can save 50% or more of the annual energy costs for heating and cooling compared to a standard home, and is also more comfortable and healthy for the occupants.
  • Sustainable Development -“meets the needs of the present without compromising the ability of future generations to meet their own needs.”— The UN World Commission on Environment and Development
  • Whole Building Design - an early term for using a systems approach to home design.
  • Zero Energy Homes produce as much energy as they consume in a typical year. The lowest cost approach to ZEHs is to first build close to the Passive Homes standard, then add renewables (usually solar electric and solar hot water).