The Challenges of Constructing Eco-Friendly Communities

Why aren’t more builders making simple changes, like a house’s orientation, that can cut energy demand by 30%?

Walk through Arvada’s Geos community and you’ll see townhouses and single-family homes lining the streets. Neighbors walk by with dogs or bags of groceries and stop for a minute to exchange pleasantries before carrying on to their respective destinations. Small lots in between each home are full of tall grasses, flowers, and the occasional bird bath.

At first glance, Geos looks like a standard housing development, but there’s a lot more going on below the surface — and right in front of your eyes — than you may think.

Michael Tavel and David Kahn of SUN Studio designed Geos between 2005–2008 and the first home was built in 2016. SUN Studio is an architecture and landscape architecture firm specializing in sustainable urban neighborhood design.

Conceived in 2004 by Michael Tavel, architect and creator of design guidelines for Geos, the first Geos home was built in 2016. Tavel is also one of the founders and principles of SUN Studio, an architecture firm specializing in sustainable urban design.

Geos is advertised as a net-zero energy community, which is probably a phrase you’ve heard bantered about quite a bit. According to the U.S. General Services Administration, net-zero energy means producing as much energy as one consumes. But perhaps Rainer Gerbatsch, a Geos resident, puts it best when he describes net-zero as “striving for a certain level of energy efficiency.”

What is net-zero?

“There are a lot of definitions for net-zero energy,” said Tavel. “It makes it confusing but there are so many ways to define it. In my opinion, the most important measurement of energy efficiency when it comes to homes is how they perform once they are built and lived in.” Tafel stated that many builders use projected energy efficiency models when applying for permits but aren’t actually looking at how the home performs once it’s built.

The homes at GEOS achieve energy efficiency several ways. The first is something seemingly simple that would be easy to overlook — the orientation of the houses. Where the sun is in the Colorado sky varies depending on the season. In the winter it’s in the more southern part of the sky whereas it rises in the east during the summer.

“The Geos homes are stretched out so that the long side is facing north and south and the short sides are facing east and west,” said Tavel. “That means most of the surface area is facing north and south, allowing you to capture more heat in the winter. The east and west sides have less surface area, so in the summer you’ll capture less sunlight.”

According to Tavel, orienting homes this way can reduce energy demand by as much as 30%. In the homes you’ll also find geothermal heating units or mini splits for heating and cooling. Builders utilize materials like three-pane windows — the standard is two — and structural insulated panels so the houses keep warm or cold air, depending on the season, inside, rather than losing it through a drafty window. Naturally this means the houses have very little airflow. To combat this, each home utilizes an Energy Recovery Ventilator, which filters in fresh air and exhausts stale air.

Arvada GEOS Community tour. Photo by Eryka Thorley.

Walkability means energy efficiency

You might look around the community and think to yourself, ‘this feels densely populated.’ There’s a reason for that too.

“The places where carbon dioxide emissions are the lowest per person are the densest cities, like Manhattan or Tokyo,” said Tavel. “The denser that we build, the less energy is consumed, both in heating and cooling buildings and transportation.”

With an increase in demand for housing, and more and more residents asking for green, walkable cities, why aren’t more developers building like this? At the very least, taking passive solar energy into account when laying out homes and neighborhoods could help reduce energy consumption.

“In the last 10 years, fracking has made natural gas very cheap in Colorado,” said Tavel. “And because natural gas is so cheap it’s removed the incentive to build truly energy efficient homes. There’s no incentive for things like passive solar.”

Tavel also notes that there seems to be an issue of government staffing when it comes to those in charge of approving building permits.

“There were a lot of interested, educated staff around 2005 who were supportive,” said Tavel. “And now, everyone’s stretched beyond their capacity. It’s been one of the greatest obstacles and it’s a national problem. Pulling building permits is just a gridlock.”

Perhaps it’s time to start looking beyond incentives, and looking toward what’s going to be better for the long haul.