Denver Tour | Images from the 2010 Tour | Other Tours

September 25th, 2010

Homes open on the day of the tour only.

Additional technical information on each home was provided in the Tour Guidebook
received by those who registered for the tour

The National Renewable Energy Laboratory Visitor’s Center (NREL) - Golden (1)

The National Renewable Energy Laboratory Visitor’s Center has been our "home" since we began hosting the Tour in the Denver metro area. We feel that the Visitor’s Center is the perfect place to get an education on energy efficient design because it is a model for energy-efficient design and takes advantage of the sun for heating and lighting and showcases technologies that can save energy, improve the environment and lower the cost of energy bills.

The Visitors Center itself is an exhibit of renewable energy and energy efficiency technologies. Passive solar energy features, energy-efficient lighting, an energy management system and other strategies help cut energy costs and optimize building performance.

An innovative Trombe wall—the building's most striking architectural feature—lights and heats the exhibit hall. The huge, undulating Trombe wall has five sections, each angled in a "V" shape. Windows on the south side of the "V" provide natural daylighting and early morning heat. Horizontal beams in front of the windows prevent direct sunlight from entering during the summer. On the other side of the "V" is a thick concrete wall coated with black paint and faced with glass. A small airspace separates the wall from the glass. Direct solar radiation is absorbed by the wall, trapped by the glass and conducted inward to gradually heat the exhibit hall later in the day

The Moore Residence - Evergreen (2)

Mike and Ann Moore’s home in Evergreen is a sprawling, must-see combination of beauty, low-impact living and eco-friendly design. Inspired by the architecture of the Pueblo Indians, the 3,550 square foot residence was designed by Doerr Architecture to be a net-zero energy home, creating more energy than it uses. With a property at an elevation of almost 8,000 feet in the Rocky Mountains of Colorado, Ann and Mike wanted a home that reflected elements of adobe architecture, provided ample space to show off their art collection, and offered views of the continental divide, all while treading lightly on the earth.

A new home with standard energy performance—as defined by the U.S. ENERGY STAR program—has a HERS (Home Energy Rating System) score of 100. The better a home performs, the lower its HERS score. While the cold and windy conditions at 7,700 feet can often present real challenges to high-performance home construction, the Moore’s home earned an amazing HERS score of -3, and stands as one of the few houses in the United States to earn this rating.

With its delightful forms, wonderful daylighting, and green design, the Moore house is proof that you do not have to sacrifice beauty or comfort to live sustainably.

Note:
The narrow mountain driveway does not allow easy access to this home. Visitors will have to park on the main road below and walk about 150 yards uphill to the home.

The Wolff Residence - Golden (3)

The Wolff residence was built with the idea that the luxury home market can and should focus on constructing beautiful, energy-efficient dwellings. This 4,117 square foot, four bedroom home is one of several on the tour that is currently for sale. At an elevation of almost 8,000 ft, the two acre property has views of Pikes Peak. Passive solar space heating is achieved by absorbing the southern sunlight gleaming in through a wall of high performance windows with tile-covered, lightweight concrete floors.

Note: Parking at the home is restricted to tour goers with handicapped license plates. All others must park in the parking lot near the property and walk about 100 yards to home.

Larson Residence - Golden (4)

Ron and Gretchen Larson have lived on Lookout Mountain for many years. Ron is one of the founders of CRES, a Chair of the Board of the American Solar Energy Society, and a Congressional Fellow who drafted the legislation which created SERI (now NREL). Ron had always wanted a Solar home. In 2001, when the US Department of Energy announced a Solar Home Decathlon to be held on the Mall in Washington DC in 2002 with entries from Universities around the country (now around the world), Ron offered to help the University of Colorado find funding their team’s entry.

When CU won in 2002, Ron & Gretchen purchased the winning home (650 sq ft) at auction from CU and added a compatible extension in 2004-2005 to increase the square footage to 2800 sq ft. They placed the building on Lookout Mountain on a lot perfect for solar with a lovely South facing view about 200 yards from the previous Larson home on Lookout Mountain. It is quite an experience to visit the home that won the world’s first Solar Home Decathlon!

The Larson home incorporates many features: passive solar, photovoltaics, solar hot water for radiant floor space heating as well as domestic hot water, super insulated walls, recycled use of materials, protection from EMF radiation from nearby radio / TV towers, extensive thermal mass and even a "Green Roof" approach to gardening.

The Doyle Residence - Golden (5)

Kathy Doyle is extremely passionate and well-informed about energy efficiency. After “becoming increasingly concerned that our energy use is putting an unacceptable burden on the planet and exposing us to serious political and security risks,” she personally researched and implemented a plethora of retrofits to this 2,998 square foot home that was built in 1992 and insists that “there has been nothing about the installation that [she] regrets.” Kathy also works towards a low impact lifestyle by recycling, shopping at the farmers’ market, and minimizing unnecessary travel.

The Stevens Residence - Golden (6)

This home, measuring 1,650 square feet, is a 1979 frame ranch home with a 1,600 square foot walkout has been continually transformed by the owner to become, a net-zero home. Sitting at an elevation of 6,000 feet in Northern Colorado, this home, once highly inefficient, now serves as a prime example of how homeowners can work with older houses instead of demolishing and building a new house with newer energy saving and efficient features.

Since 2001, Steve has added the use of a swamp cooler, a plug-in vehicle, and radon remediation, and still has managed to reduce his carbon footprint by well beyond 130 percent. In 2001, the home’s energy use was the equivalent of emitting 14.8 tons of CO2 to the atmosphere. As of 2009, the home net energy use equated to removing 6.6 tons of C02 from the atmosphere.

As the 2009 CRES Volunteer of the Year award, Steve believes in climate change, peak oil, and resource limitation and feels that it is necessary to have examples for people to see that a zero carbon lifestyle is both feasible and cost effective. By following Gandhi’s advice, and aiming to “be the change you wish to see in the world,” Steve’s ultimate goal is for his grandchildren and their children’s children to inherit a livable, strife-free world. He believes that solving the energy issues facing the world today needs to be the top priority for Americans.

The Redmond Residence - Golden (7)

This home is the first solar urban farm ever featured on the tour. The house sits on nearly two acres of land, most of which is used to grow commercial produce. This house, constructed in 1971 “with all of the worst building materials and techniques,” is still a work in progress. However, as the owners recognized that it was “perfectly suited for solar PV.” As such, the PV array that powers the house is now mounted on the large roof in addition to the 48 zones of drip irrigation. This watering system uses a weather network to apply exactly the amount of water needed for the type of produce in each zone. In the future, the owners plan to add a sunspace, insulation, a wind system, Low-E windows and a plug-in vehicle, along with other improvements.

It’s no surprise that owners with backgrounds, in urban planning, landscape architecture, biology and geology (as well as other things) have come up with the first completely solar farm in the state!

The Grossman-Dadisman Residence - Golden (8)

This two-family house, built out of bales of straw, is a large one. Straw bale houses have both extremely thick walls with a high insulation value, resulting in a warm house with wonderfully deep window sills. Because roofs cannot be made of straw, the owners used a SIPS (structurally insulated panel system) product to achieve the R-38 roof. It is a somewhat complex house in that it has both curved and straight roofs and a two story sun space in the center of the house. You will notice a huge boulder in the sun space which adds some interest and some thermal mass to the room. The passive solar heating is achieved with glass and mass, in the form of exposed and stained concrete floors. The amount of mass helps keep the temperature much more even and helps to eliminate the large temperature swings. The owners were able to put up the straw bale walls with the help of 20 friends, and all they had to do was feed them with beer and brats. The owners have also done some of the construction themselves, both because they wanted to and because they have had a hard time finding qualified sub contractors. One of the owners, Pat, is the membership director of the Colorado Renewable Energy Society (CRES), and has taken much of the information she has learned over the years and put it all into their new house.

The Bassi-Rubenstein Residence - Golden (9)

The Bassi-Rubensteins have made some upgrades to their 1979 house. They cite the added insulation in the roof as “a very good addition.” The solar thermal system from the late 1970s has been tied to the new, ultra modern and flame-free furnaces. Water is heated by the sun, and a boiler that holds two gallons of water increases the temperature of the water when necessary. A pump sends the hot water to heat exchangers at the furnaces. The heat exchangers transfer the heat from the hot water to get the air flowing from the furnaces, where it is distributed throughout the house. While the house was considered modern when it was built, and the owners wanted to update it to keep it modern in an energy sense. Air conditioners are not run in the summer since the house has so many windows. In winter, the house keeps the warmth from the sunlight, so thermostats are set to 52 degrees at night.

The house’s pool is heated with solar, minimizing costs to run it each season. While the owners have considered thin film for solar PV, it was deemed out of their preferred price range. The owners cite their only “energy waster” as a 12 section sprinkler system installed by the second owners that’s run a couple days each week. The Bassi-Rubensteins currently have no plans to make additional changes to the house.

The Nelson Residence - Lakewood (10)

This moderately sized house was built in 1956, is considered by its owners to be a “pretty successful remodel job” that boasts a number of solar additions. The owners both work at NREL, so if anyone would know what technologies are available, it is these two.

The home shows multiple solar technologies (daylighting, passive solar, active solar, and two kinds of PV). Climbing up a wall-mounted ladder on balcony allows one to see the a-Si and solar hot water.

What would they do differently?
First, the owners would mount the solar thermal to roof pitch, but instead tip it up to be more vertical than horizontal. In fact, the owners might change the arrangement to have one panel at roof angle and one vertical on a wall.

Secondly, they’d choose to focus PV on appearance, with an all a-Si on metal roof OR focus on more powerful and efficient c-Si and push the 10 kW Xcel limit. The existing envelope is brick on block, and it is difficult to improve the wall insulation without either significantly changing the exterior look or loosing interior room area.

Next they’d place the Solatube over the kitchen sink instead of right in the middle of the kitchen.

Lastly, some accommodations would be made to keep snow from coming off the a-Si PV and falling on the deck steps.

The Geiseler Residence - Denver (11)

This is the oldest house on the Tour, built in 1888, and is in a neighborhood that features other lovely homes with mature gardens. What makes this an interesting retrofit is all of the ideas that have been used on this house. It demonstrates that there is something that can be done for every house regardless of age. One of the techniques on this house is the semi-Trombe-Michel wall. While it is definitely glass with a mass wall (two feet thick, no less) behind, the masonry wall is still exposed to the exterior cold temperatures beyond the edges of the glass enclosure. However, even with the migration of heat from the enclosed area to the exposed area, it still helps heat the house. The wall is vented into the house so as the air is heated up during the day it is spilled into the house and triggers a thermostat-controlled fan. The hot air is also directed through a rock storage bin.

Due to the upgrades the owners enjoy the savings and the efficient kitchen and bath, the opportunity to improve the performance of the three heating systems, and the replaced plumbing, electrical and heating systems. Up until last year, the house was outfitted with wiring that was 120 years old, which posed a real and significant fire risk.

The Sullivan-McMacken Residence - Denver (12)

This is one of the older homes on the tour, juxtaposing a historic home with modern features. It was built in 1924 and is on a very pleasant street in the Sunnyside neighborhood of Denver. This home has been very tastefully updated to make it both attractive and energy efficient. It produces 100 percent of its electricity and is a great example of the many things city dwellers can do to make homes and neighborhoods as sustainable as possible.

The owners have managed to incorporate a comprehensive garden, solar technology, and energy efficient appliances to make efficient use of a small space. The solar array is very sleek and modern and shows that solar PV can in fact be attractive. The gauge that monitors the home’s electricity usage against its solar production is an excellent learning tool and visual aid to show how solar PV works on a real time basis.

The owners want their house to serve as an example to the neighborhood, and have already convinced two more homes on our block to “go solar.”

The Kahn-Stevens Residence - Denver (13)

This 1901 house, located 11 blocks north of City Park Golf Course, is a complete remodel that’s been gutted from top to bottom. The homeowner, a professional energy rater, has added foam board and insulated walls to the gutted house. The home now has between five and seven inches of insulation inside the brick shell. The home was also plumbed with in-floor radiant heating and solar hot water panels on the roof. In the future, the homeowners plan to add a veranda on the south side of the house with PV on the roof of the veranda to generate electricity for the home. The house is pre-plumbed for the addition of two more solar thermal panels in the future.