Front and back views of the Juniper Showhome

Aspen Homes
Juniper Showhome

Participants:
Rob and Jammie Sabin - Aspen Homes
www.aspenhomesco.com 

The Juniper Showhome was designed and built with all solar concepts in mind in an effort to achieve the concept of a Net-Zero home where the home produces as much energy as it consumes in one full year. 

In an attempt to bring net-zero living to the general public, Aspen Homes has strived to make this type of home affordable.  Aspen believes that if they can make the concept of a zero energy home economical, they will be able to change the market towards new energy efficient construction.

Building Details:

Building square footage: 1448 finished, 1448 unfinished
Construction cost per square foot: $114 per total sq. ft.; $229 per finished sq. ft.
Date of completion: July 2008
Number of bedrooms (residential): 3 bedrooms
Initial sales price and date of sale (residential): $332,616.00
Non-renewable heating source (gas, electric, propane, etc): Acadia 3-Ton All-Climate Heat Pump (200% - 450% efficient)

1. Use of Renewable Energy:

Solar thermal and photovoltaic panels on the rear roof of the Juniper Showhome

The home at 291 Saratoga Drive was designed and built with all solar concepts in mind in an effort to achieve the concept of a Net-Zero home where the home produces as much energy as it consumes in one full year. In an attempt to bring net-zero living to the general public, Aspen Homes has strived to make this type of home affordable. Aspen believes that if we can make the concept of a zero energy home economical, we will be able to change the market towards new energy efficient construction practices. Below is a list of the major components that put this home on the cutting edge of energy-efficiency and resource conservation:

• Designed to significantly reduce electrical loads on the home with energy efficient lighting, heating, and cooling which will ultimately lessen the impact of this home on the environment.

• All electric – Thru on site electric generation, the customer’s personal carbon footprint will be drastically reduced, thus decreasing or eliminating the demand for fossil fuels at this home.

• 4-kW grid-tied Photovoltaic Array (Sharp Panels and Fronius Inverter) providing on site electrical generation and allowing excess electricity to be sold back to the utility company for credits to be used later.

• Acadia Air Source Heat Pump provides 200-450% efficient space heating and cooling with a HSPF of 9.6. The variable speed air handler reduces noise while using 1/3 the electricity of a standard air handler.

• Exterior Foundation Insulation (R-10 Rigid Dow Insulation under slab and outside foundation walls) ensuring the home has a tightly insulated thermal envelope

• 2x6 Blown Optima walls with R-5 Rigid Dow Insulation encompassing the wall assembly (total R-28 walls) and R-50 Blown Cellulose Attic.

• Passive solar design w/ 2’ overhangs to the south and calculated window heights to allow for shading in the summer and passive solar heating in the winter.

• HRV (heat recovery ventilator) with ducted wet rooms gives optimal comfort, air quality, and efficiency by tempering fresh air prior to mixing with the return air in the HVAC system. This allows the house to properly remove the stale, humid air, while recapturing the heated/cooled air while maintaining optimal indoor air quality. All standard bath fans were removed from this homes’ design and were replaced by the HRV.

• Compact florescent lighting package that uses ¼ of the electricity of standard light. The pin-based fixtures will push future homeowners to continue using energy efficient light bulbs.

• Solar hot water panels and tank are connected to an electric tankless hot water heater. This optimizes the solar thermal panels while providing the customer with endless hot water.

2. Environmental Impact:

The home was designed so that it will create as much energy as it uses in one year. The key feature of this net-zero home is that it is 100% electric. All of the home’s power is generated on site through a net-metered solar photovoltaic system where it builds up credits in the spring and summer and uses the credits during the cooler months. By eliminating the need for natural gas this home will decrease the owner’s carbon footprint considerably. From July 2008-March 2009, this showhome has consumed only 3000 kWh (a standard home uses 800-1200 kWh per month with additional gas consumption). From the PV system alone we are reducing annual CO2 emissions by 11812 lbs (see attached report from Namaste Solar). Per our E-star rating, the house as a whole will reduce CO2 emissions 23,430.60 lbs/yr (see attached energy rating packet). This means less pollution and a healthier community.

All of the home’s heating and cooling is provided by the 3-Ton Air Source Heat Pump which delivers efficiency (200-450%) nearly equal to a geothermal heat pump but at a fraction of the cost without the need for a loop field. This allows the entire house to be solely electric so there are no hidden carbon sources that make true net-zero impossible, such as a natural gas furnace or fireplace. The attached
variable speed air handler and HRV (heat recovery ventilator) increase comfort by removing the humid, bad air and distributing fresh air at an even temperature throughout the home improving indoor air quality. Additionally, in combining a solar thermal hot water system with a flow-thru electric tankless hot water heater the home will have an endless supply of hot water even on cloudy days. Through this innovative technology Colorado's sunshine creates renewable energy, conserves natural resources, and will save homeowners money.

3. Aesthetics:

The Greenspire subdivision and specifically the lot for 291 Saratoga was selected because of the solar access and orientation. Created with a passive solar design, the home has 2’ overhangs to both the front and back of the house, calculated window heights, and covered patio around the sliding glass door. This integrated design maximizes efficiency and comfort while significantly reducing its environmental impact. To ensure that the home’s design would provide optimal shade coverage throughout the year we completed an overhang analysis (see attached). This home has 97% solar shading in the 3 summer months as well as passive heating during the winter meaning there are less energy costs spent throughout the year.

4. Public Awareness:

Open seven days a week, our Juniper model showhome at 291 Saratoga Drive is located in the Greenspire Subdivision in Windsor, Colorado. Inside the sale’s center, there is a well-stocked supply of literature on the energy efficient features Aspen Homes incorporates into each of their homes. Displays, posters, and informative tags are placed throughout the home providing visitors with details and explanations about the many benefits of building and owning a sustainable home.

Featured in the 2008 Parade of Homes for Northern Colorado, the Built Green University Tour, and the National Solar Tour (via NCRES) the home has served as a milestone in educating the public, including other builders and tradesman, about the net-zero concept. Aspen Homes will also be presenting the home to the future Energy Green Builders Club with CSU in early April 2009. The tour will focus on educating young adults who plan on entering a career in construction/engineering about energy efficient building and design.
In addition, the net-zero home was recently named Built Green Home of the Year Award for 2008 in the $250,001-$500,000 price category” and was recognized in a number of newspapers, including the Coloradoan, the Northern Colorado Business Report, and the Loveland Reporter-Herald.

5. Replicability:

Through the example of our model home, Aspen hopes to spread awareness about net-zero living throughout the housing market. The Juniper model is a standard model that we offer in all of our subdivision. All of our customers are given the opportunity to build with the net-zero option or to have only some of the net-zero features integrated into their new home. Ultimately, our goal is to show builders and homeowners alike that the net-zero concept is feasible, environmentally sustainable, and a financially smart option that will ensure a better future for generations to come.

Other Information:

1. E-Star certificate and ratings
2. Built Green Certificate & Checklist