Off the Grid Sustainable Housing Options

Straw Bale Homes:

You can compress the straw bales using a piece of plywood and car jacks and a piece of plastic to help slide the bale. Having the bales compressed adds strength to the wall and keeps bales from slipping against each other. Straw bales can also be modified using a chain saw to notch around framing members, electrical boxes, etc. Bales can have one string re-tied short so the bales can be curved around windows. Niches and other sculptural features can be added with a chain saw after the wall is in place. Light-clay-straw for filling voids – Straw bale walls will inevitably have voids that need filling, especially at the corners of bales. Stuff deep holes with dry straw at first and then start adding clay-slip to your straw so that the final stuff has a serious amount of clay. Work this clay straw into the cracks between bales to secure it into the wall. It will dry to a hard firm surface that can take plaster beautifully. Big Overhangs – It can’t be said enough that big overhangs will help protect your straw bale wall. If you want to do exterior plaster with earth this is essential. A two foot overhang at 8 feet high is a minimum and consider porches, trellises, and other landscaping to block rain and break up wind. Large window sill to run water away from the bales Big window sills – Water running off of windows can damage plaster below the windows. By having a window sill that sheds water away from the building plaster can be preserved and leaks prevented.

Passive Solar Design – When trying to incorporate passive solar heating it can be difficult with a load-bearing straw bale home to get enough window space on the south side of the building without losing structural stability. One can have posts and a beam for the south side alone but you must then plan for bale compression on the other sides.

Earth Contact – Insulation is great but direct contact with the earth is what helps keep a straw bale home cool in the summer and easier to heat in the winter. 

Prevent Infiltration at the Edges – The effectiveness of insulation is greatly diminished if air can infiltrate the house. This often happens at the edges of doors, windows, ceilings, foundations, and wall sections. Careful plastering at these points can help but shrinkage occurs with drying and temperature changes and cracks can develop. Caulk can help but the ideal thing is to overlap plaster onto the rough framing and right up to the exposed trim.

Finish: Most Straw Bale Homes use Lath and Plaster over the straw for interior walls and either Lime Plaster or Stucco over the exterior. Straw bale home are fire resistant and measures a 2 Hour rating and provide an P-35 or R 50 insulation rating.