Exploring net-zero housing Nederland’s mayor and members of the Sustainability Advisory Board (SAB) met with the developer and residents of the net-zero housing development in Arvada on October 28, 2022. Above;The front of the neighborhood with south facing rooms and buildings off set to capture the sun. PHOTO BY JOHN SCARFFE[/caption]

Nederland’s mayor and Sustainability Advisory Board (SAB) met with the developer and residents of the net-zero housing development in Arvada on October 28, 2022. Manager and developer Norbert Klebl of the Geos neighborhood just west of Indiana Street on 69th Street in Arvada said all the units are self-powered through solar.

The Geos neighborhood combines traditional village living with the most advanced design and building practices. Community members enjoy a pedestrian-focused lifestyle with front porches, tree-lined sidewalks, and access to open space.

Advanced building technology and solar orientation reduce buildings’ energy requirements by 75 percent. Geos utilizes the sun to produce as much energy as each residence consumes, with total costs that are marginally higher than standard homes.

Larry Tasaday with the Nederland SAB arranged the meeting from Nederland and was joined by Eryka Thorley and Mayor Billy Giblin.

The appointed SAB advises the Nederland Board of Trustees to execute improvements to Town codes, operations, and facilities on matters regarding sustainable practices, resource conservation, renewable energy, waste reduction, public outreach, and education.

The group met with Klebl and two residents of the Geos neighborhood in the neighborhood office. Klebl was the master developer of Geos. He earned both a European engineering degree and an MBA from Columbia.

Currently he is master-planning and designing Geos, the net zero energy community in Colorado where all buildings will be so well insulated and airtight, that passive solar and geo-thermal energy will allow heating and cooling with an energy recovery ventilation (ERV) system. The concept will reduce energy needs by 75 percent compared to current building practices and make sustainable residential buildings affordable.

He said he was from Austria, where they have 20 percent net-zero housing. He ended up in Boulder 25 years ago. Through the Green Building Guild, he met craftsmen in Boulder and scientists in Golden, so he decided to bring them together. They met monthly.

Needing to find a workable system, he took six of his scientist friends to Austria to help find a solution. Net zero building needs to be created from the bottom up, he said.

Twenty years ago, in 2002, this kind of sustainable building cost 100 percent more. He realized that builders can get close to a passive house with only a 30 percent increase in cost. He had to form his own team to build it.

Klebl owned 25 acres of land. He developed the design on 20 acres not including the green space.

“I had put together the Geos home,” Klebl said. It is all facing south, and includes the insulated double pane windows made by ALPEN High Performance Windows in Louisville, Colorado.

In order to reach their goal, they needed to tighten the buildings. The magic number for air exchanges in a house is one complete change per hour, so they have mechanical ventilation systems and sensors that measure CO2 levels. These houses have air quality equivalent to that of a hospital. Quality air control is the backbone of the mechanical system, he said. It recirculates the inside air for energy savings.

The neighborhood has 28 homes like this. He offset the buildings so each would have enough exposure to the sun to provide adequate solar energy. The City of Arvada approved the buildings.

“The existing 28 homes have operated essentially for years at net zero energy. They are fully electric, not using any natural gas, and powering 16 electric vehicles,” he said.

“The neighborhood consists of a variety of home models: townhomes, duplexes, and single-family homes. They all come in with a Home Energy Rating System (HERS) rating around zero.”

This unique performance, he said, is achieved by

1. Orienting all homes with major walls and large windows to the South to allow maximum passive solar gains in the winter and good overhangs for the summer;

2. Improving insulation and reducing infiltration to under an ACH50 (Air Changes per Hour) of 1. Most standard new homes rate at 6 to 8. Improving fenestration to triple pane ALPEN windows with an R value of 6.5.

3. Installing an advanced new mechanical system based on energy recovery and heat pumps.

Twenty years have now gone by, and the industry hasn’t changed, Klebl said. Nationwide, he complains, builders are all the same from Texas to Maine. They build the same thing over and over.

The meeting ended with a tour of one of the resident’s homes.

For more information on the Geos Neighborhood, go to https://discovergeos.com/