What is green construction? There are so many variables as to what makes a building green or not it is hard to know whether a given building style, construction method or material is “green” or not. To me green building must take into account the embodied energy of the components, the future energy required to operate the house, the toxicity of the building materials themselves and their manufacturing process, the quantity of resources required to build the home, the life-cycle and replacement date of the building and finally the impact of abatement or disposal of the building at the end of it’s lifespan. Now it’s nearly impossible to quantify all of these aspects and what may be true in one part of the world definitely isn’t in others. However there are some generally accepted truths in green building we can rely on to tell us some things we want in our buildings.
- higher insulation levels
- compact building footprints and efficient space planning
- low embodied energy materials
- few PVC or petroleum derived products
- passive solar heating and lighting
- energy efficient systems and fixtures
- recycled and recyclable materials
When planning a new building the very first thing you should consider is what are your needs and wants and are they realistic and necessary? A lot of people think they need a formal dining and sitting room but if you look at the amount of money it costs to build a home per square foot, how much it costs to heat a home per cubic foot and how often these rooms are utilized it quickly becomes apparent whether they are real needs or frivolous wants. build what you need in a home and no more.
The second thing to look at is where the building is going to be built and how you can take advantage of the site natural benefits. Is there a way to use southern exposures for passive solar heating and lighting? Are there buffers against wind via trees or berms?
Thirdly look at your buildings envelope and insulation methods, and design your home with as much insulation as you can. Any building in any climate benefits from high levels of insulation, it keeps heat in in cold climates and heat out in warm ones. It also lasts the life of your building and can make the heating or cooling requirements so small as to only require minimal supplementary help. Have a read of the post Heat Loss Myths for more info the different ways heat is lost (or gained).
Lastly look at your building heating and cooling systems, domestic hot water systems and appliances. If you have designed the first three steps optimally then this step becomes less critical and the systems you will need for your house may be of reduced capacity saving you money up front and being more efficient.