How Much Does It Cost to Build an Eco-Friendly Home?

Americans spend an average of $7,068 per year on utilities. That’s $70,680 over the course of a decade—double, or perhaps even triple, what most Americans earn in a single year.

Numbers like these make an off-the-grid living and “green” homeownership look mighty attractive.

Solar-powered electrical systems, rainwater catchment tanks, and other innovative design features and building materials would surely help reclaim income lost to utility expenses. But what’s the overhead here? Just how much does it cost to build an eco-friendly house and “go green” entirely? The determining factors vary drastically from project to project, but we've got some rough estimates below.

Green Building Materials

Let’s take a look at the types of green building materials on the market and the general price points associated with each.

  • Cob – A mixture of straw, sand, and clay, cob is a resilient, long-lasting building material that can cost as little as $3,000 to make (this does not include labor-related expenses, only material fees—cob is not suitable for cold-weather climates!)
  • Hempcrete – Hempcrete, or hemp concrete, is a much more ecologically friendly building material than conventional concrete; five cubic feet worth of hempcrete can cost as little as $30
  • Straw bales and lime cement plastering – Though straw can cost anywhere between $2 and $15 per bale, additional construction materials and plaster-related necessities jettison up the overall price tag to around $15,000 (again, this figure does not reflect labor expenses, only materials)

Prefab Alternatives for Creative Homebuilders

For those uninterested in building from scratch, there are all kinds of possibilities to fashion homes from preexisting structures.

  • Boxcars – Used boxcars can generally be found through online retailers like eBay in the $5,000 - $20,000 range.
  • Grain silos – A more cost-effective alternative to boxcars, smaller used grain silos tend to run in the $3,000 - $5,000 range; new or large silos are pricier, at $20,000 and above.
  • Shipping containers – Perhaps the cheapest and most popular choice for creative homebuilders, shipping containers can be secured very cheaply, at anywhere from $1,500 - $8,000. You can even buy a prefab tiny home in a shipping container from Amazon

Eco-Friendly Energy & Water Sourcing

Unfortunately, sourcing your power and water through solar panels and rainwater catchment systems can be overwhelmingly expensive.

  • According to, a 5-kW solar panel system could cost anywhere between $25,000 and $35,000; there is hope, however, for the financially strapped among you—certain utility companies will pay for as much as 50% of costs associated with solar panel systems, or otherwise offer other incentives for their purchase
  • The price of a rainwater catchment system depends largely upon how much water you hope to store in it—a larger size generally means it’s more expensive; Texas resident John Knight, who has harvested his own rainwater since 2001, told those at Texas Co-Op Power that “A complete rainwater harvesting system for a typical single-family home will generally cost between $8,000 and $10,000”

Since specifications and preferences for each green building project vary so wildly, it’s a fool’s errand to try and determine turnkey costs.

Still, these price ranges offer greater insight for those in the initial stages of the green homebuilding process in determining which options are the most cost-effective for them, given their long-term potential savings benefits.

For some, modest green adjustments to an existing property, like a fixer-upper, may be a more financially feasible strategy than building something from scratch. Others may have the capital necessary to embark on a green homebuilding odyssey.

In spite of the cost-prohibitive nature of green homebuilding, the long-term benefits could not be more clear: a reduced carbon footprint, as well as greatly diminished utility bills, make it a more than worthwhile investment.