Sunday, August 18, 2013

Pin Foundations: A Very Green Foundation System

Here is a very  inexpensive and non-invasive foundation system that is slowly gaining popularity.  What is holding it back is typically conservative builders and structural engineers.

If your jurisdiction requires a soil report, then you may be able to find a geotechnical engineer who can work with the engineers at Pin Foundations and get the structural plans stamped.

The floor insulation and moisture vapor control details are important:

In most cases, this system means:
1.  No excavation contractor
2.  No poured footings
3.  No concrete forming or stemwalls
4.  No concrete delivery trucks using diesel and disposing of waste concrete

Since the system eliminates conventional concrete work, many would consider it very green.  Concrete work is still tolerated by most green builders due to its durability and longevity, but the concrete industry is apparently one of the top contributors to global warming.


  1. But you end up with a questionable crawlspace - one with only plastic is vulnerable to mice and other critters. But if you pour a slab in the crawlspace, then you have to ask why bother.

    The Swedish frost protected slab on grade system is better. Same benefits of no excavation, no stem walls, no formwork.

  2. Greg,

    We are using an American frost protected mono-slab on grade for our first projects. The concrete can be the finished floor, which is a big savings:

    But a two inch rat slab for a pin foundation is inexpensive compared to an engineered mono-slab or a Swedish raft slab. Even cheaper is an extremely tough 20 mil reinforced plastic ground vapor barrier:

    In a year, I'll have real cost comparisons.