By Michael Tausch
As the owner of a “green” home now under construction, I am often asked about the costs of such a project. For many people the basis for that question has to do with the home’s more glamorous features, what I call the “bling”, meaning features such as solar panels and other alternative energy generating systems or the home’s energy-storage capacity. Rarely do they ask about the cost of the structure itself, presumably because they assume that a conventionally built structure. That may or may not be the case. For me, the answer definitely fell within the “may not” category.
The home I’m building in Vancouver, WA, is a concrete structure, more specifically, a “SCIP” home. (“SCIP” is an acronym standing for “Structural Concrete Insulated Panels”). SCIPs consist of panels comprised of foam over a wire mesh which, after being assembled, are covered on both sides with a layer of concrete (more specifically, shotcrete). The finished SCIPs thus form both the interior and exterior walls of the home.
Challenges of Building A SCIP Home
What is it about SCIPs that make them a “green” building choice? There are many reasons but one of the primary reasons is that their insulation value is considerably higher than that of a wood-framed home. This is because the foam, though a solid, is comprised primarily of air and air is a good insulator whereas wood is not.
So far, so good. Whether or not SCIPs are an appropriate and affordable building methodology depends on a number of factors. Currently, building a SCIP home almost by definition means constructing a custom-built home since “production home” builders (“production homes” are homes found in neighborhoods constructed by one developer or are built on a lot according to the “model” chosen) have, except in a few areas of the country, avoided pretty much any building methodology outside the tried and true. The advantage of production homes to the homebuyer is that their builders can employ economies of scale and thus price their homes lower. Unless one lives in an area where SCIP developments have already found a niche, finding a firm to do the job probably means importing a work crew from elsewhere which, of course, means paying for lodging and transportation of multiple persons and can prolong the home assembly process.
The second issue facing the homeowner contemplating SCIP construction is determining the number of panels the home will require. The answer to that question depends on the configuration and square footage of the home. SCIPs come in different sizes and are fabricated by different manufacturers, so giving a specific figure for the cost of panels applicable to all homes is not possible. As an example, however, I can tell the reader that the cost of the panels for my home of approximately 1600 square feet in size ran around $50,000, inclusive of transport.
The Cost is in the Concrete!
Determining the number and cost of panels is only the beginning. In order to become true “SCIPs”, the “SC” (Structural Concrete) has to be added to the “IP” (Insulated Panels) and this is where the costs can really mount up! The depth of the concrete sheathing depends on the climate area in which the home is located. Since I live in an area with a temperate climate, 1 ½ inches of concrete on each side was deemed adequate; for those who live in areas susceptible to more temperature extremes such as the heat of summers in Arizona or the frigid temperatures found in the far reaches of Canada, the thickness of the concrete will probably be more. The differences between depths can be dramatic. In my case, calculations undertaken to prove compliance with the local energy code showed that if the outside temperature dropped by 50 degrees, the use of the 8 inch thick (5 inches of panel width and 3 inches total of concrete) SCIP walls and roof in conjunction with triple-glazed (paned) windows would result in the interior temperature of the home falling by all of one degree!
That’s impressive – but so is the cost. The cost of the concrete depends on the home’s square footage, but here I refer not to “square footage” in terms of floor space but to the square footage of the panels. Warning: This is where one might feel the need to faint.
My 1600 square foot home has a panel surface area of 14,700 square feet. That means that 14,700 square feet have to be covered with 1 1/2 inches of concrete. That is a lot of concrete and, at prices ranging from $8 per square foot, a lot of money. Taking all of these issues into account, it is the cost of the humble, homely (no pun intended) concrete – not the insulated panels themselves, not the energy generating equipment, not any of the other features one typically associates with a green home – that make building with SCIPs a financial challenge for the average homeowner. To put it bluntly, one could build a conventional home with “green” features such as Energy Star appliances for less than just the cost of the concrete involved in building a SCIP or other type of concrete home.
SCIP Benefits Beyond Energy Savings
As with all things having to do with green construction, however, the higher initial cost of building the home may (and should!) be offset in the long run by lower energy consumption and, hence, lower energy costs. But there are other considerations. Concrete homes, for example, are remarkably durable, with a lifespan measurable in centuries rather than decades. (Well, okay, I don’t know too many 300-year old homeowners, but for those of us concerned about the efficient use of resources, indeed, the very availability of resources in the future, this is a point that can’t be overlooked.) Concrete homes also require less maintenance than wood framed homes, are resistant to fire, termites, and other such hazards. They are distinctly quieter than the conventional “stick-built” home which could impact their value in area where traffic or other noise pollution is a factor.
Thus, the decision to “go green” with SCIPs is one with multiple pros and multiple cons. As for the cons, I think that as the technology proves itself and as it becomes more familiar, costs will come down. From my own perspective (so far) I stand by my decision to use SCIPS. Yes, there have been many headaches along the way, but I think most of the anxieties I’ve felt are ones shared by anyone building a home, regardless of the construction methodology. My intention from the outset was to procure a nice new home for myself, but also make a statement to the community: It’s time we re-evaluate the way we build our homes. Given the feedback I’ve received, I think I’ve been successful in that objective. I also take pride in the fact that this is the first SCIP home in Southwest Washington, which makes those headaches a lot more bearable.
My last bit of advice for the other homeowners considering SCIP construction? Do your homework. And have a bottle of smelling salts handy.
Michael Tausch is a retired attorney living in Vancouver, WA. When not spending money building his home, he devotes his time to numerous environmental causes and writing projects. You can read more about the construction of Michael’s home at http://sylvanecohouse.com.