Previously on RRR, we talked about a little issue with rebuilding the work studio out back: Namely, the foundation isn’t sufficient, and we’re going to have to jerry-rig a new one.

Before we move along, though, does everyone know what a foundation is and does? Basically, it attaches your house to the earth, so the forces of wind on your walls and the weight of snow on your roof don’t crush your little casa, and so the weight of your walls and roof has something to stand on.

Now that that’s out of the way, let’s talk about something called frost heave. This is not what happens the morning after snowmen have a little too much eggnog. (You know what happens when I have too much eggnog? Really bad puns.) When it’s cold, moisture in the soil – particularly soils like the clay we’ve got in Colorado – can freeze, which makes that soil expand. The soil’s freezing and thawing and expanding and contracting can play hell with a foundation, making it crack, making your walls warp, and making your repairman rich.

To avoid all this – and stop me if you know all about frosts and foundations, cos it’s all new to me – your foundation should sit on soil that doesn’t freeze, soil that sits below the frost line. We’ve talked about the frost line before, way back on our geothermal heating jag this winter; it’s the depth in the ground below which the earth doesn’t change temperature, where the soil ceases to freeze. Here in Colorado, you’d have to dig down around three feet to hit the frost line. Dig down three feet and pour a wall of cement, and you’d have the basic setup of probably 90 percent of the home foundations in America.

A little aside. I was digging a post-hole the other day, and once I got to about 18 inches I discovered why this town’s called Boulder: rock after rock after rock. It took me about seven hours to dig that hole. So digging a three-foot-deep trench around the perimeter of my studio isn’t really a fun idea. But there’s another (and yes, greener) option: With a frost-protected shallow foundation, or FPSF, you dig down only half as deep, 16 inches, but you insulate the foundation walls from the surrounding ground. Protected from the temperature change this way, the ground under the studio will pull a steady temperature from the geothermal power of the earth, meaning frost has no purchase. Voila:

You also pour a shorter foundation, meaning you use less cement. Cement’s one of those gray area materials. It’s got a super high embodied energy, meaning the energy it takes to produce and ship it – U.S. cement consumption produces more carbon dioxide emissions than 20 million cars, according to David Johnston – but it’s also one of the most durable building materials. Shortening your foundation wall by using an FSPF can reduce your cement dependency considerably – around 40 percent. Plus, you know, less digging.

Anyway, the plan for now is to go with an FPSF – which I’m pronouncing “fipsif,” by the way. If we ever get out of the planning stages, that is.