Question

What materials should I use to build an eco friendly home?

Asked by Stephanie
Akron, OH

I have an Environmental Science project and we have $1 million budget to build an eco friendly home. We have to include exterior and interior materials.

Answer

Polly Osborne, FAIA, LEED AP

Answered by Polly Osborne, FAIA, LEED AP

Los Angeles, CA

Polly Osborne Architects

January 23, 2012

Dear Stephanie,

The first thing to consider in your eco friendly home is site.

  • Place it near a bus stop, so you don't have to drive.
  • Find a spot with amenities you can walk to.

Then, ask yourself these questions about your site, so you know how to shade the house with overhangs and trees and strategically place windows to be prepared when summer comes.

  • "How does the sun come across the sky?" When you know the answer, you'll know how to orient you house to stay warm in the winter.
  • "How do the shadows fall?" and
  • "Which way is the prevailing wind?"

These simple questions above, if asked for every house built, would save people thousands in energy costs. 

  • The sun, our best and cheapest form of heat, will warm up materials, such as stone or concrete, that will hold the heat they gain in the day and release it through the night.
  • If you insulate on the outside of such a material, called "Thermal mass," the released heat will radiate back into the house and keep it warm.

Materials

There are some rules of thumb when seeking eco-friendly materials.

  • Wood, if a fast growing species, will replenish itself quickly, therefore it would be a better choice than a tree that takes a long time to mature.
  • Steel is a good choice, because so much of it is recycled. It has a problem though, it isn't very energy efficient. So if you use steel, be sure you have plenty of insulation between it and the elements.
  • Concrete can also contain substantial amounts of recycled product if it is specified in the mix.

For surface materials, there are many glass, quartz and ceramic tile and countertop slab materials on the market with recycled content.

  • Floors can be made of wood grown sustainably or reclaimed from other sites, or linoleum, which is made of wood and oils.
  • Walls could be of natural clay or lime plaster.
  • Paint and other finish products should be low or zero VOC (volatile organic compounds) which will not off-gas toxins into the atmosphere causing "sick house syndrome."

Building envelope

Exterior siding could be paper compressed as rainscreen, such as "Paperstone," reclaimed wood siding, lime plaster or a composite insulation material that already has a weather resistant surface.

Your roof should be of reflective material so it doesn't get too hot in the summer.

You'll want to insulate very well, and fill all cracks between materials in the walls, roof and floor so the is no infiltration or gaps. If you do this well, it is also important to ventilate the house so there is plenty of fresh air, even in the winter when all the windows are closed.

Lighting

Lighting should be done with LEDs and fluorescent bulbs.

Natural lighting through windows, skylights and clerestories should be taken into account so that electricity doesn't have to be use during the day.

Water, waste, energy

Make a gray water system for the washing machine. Have a place for compost under the sink. Use energy efficient appliances and plumbing. 

Beauty

Make your house beautiful. Beauty attracts people to our cause of being green.

 

For more information:

Read Green Home Guide's articles. They are full of good information.

And here are some more websites you may enjoy visiting:

Do you have a question about greening your home? GreenHomeGuide invites you to Ask A Pro. Let our network of experienced green building professionals – architects, designers, contractors, electricians, energy experts, landscapers, tile & stone specialists, and more – help you find the right solution.