Energy Value Housing Award -- Chino Valley, Arizona

An academic pursuit providing real world results

This luxury home is representative of a growing number of programs that provide both training in environmentally responsible building practices as well as real sustainable housing. It is the product of the Residential Building Technology (RBT) Program at Yavapai College, in Prescott, Arizona. In 2007, this project was given an NAHB Energy Value Housing Gold Award while also complying with several other sets of standards including LEED, EEBA and ALA HealthHouse.

The Longview House was designed to conform to the RBT program's mission, which strives to produce healthy, durable, affordable and efficient housing. Nearly every process was addressed in making the home efficient to build as well as live in. The use of pre-manufactured roof trusses and foundation walls expedited construction, while carefully installed insulation, an extremely tight building envelope and a rainwater collection system will limit future energy and resource needs.

The RBT program is equally concerned with the environmental impact of their work. Careful planning helped minimize disturbance of the site and its existing vegetation. The addition of drought tolerant landscaping further inhibits storm-water runoff - an important concern in this arid and hilly location.
Although it may be atypical with its use of university student labor, this project is a great example of how smart design can facilitate increased sustainability within a typical budget. An NAHB Energy Value House judge’s comment - “if only every house built in the U.S. could have the oversight of this project - our houses would be energy efficient and durable”, is a testament to the commitment of the RBT faculty and students.

Team:
Builder: Yavapai College Residential Building Technology Program, Tony Grahhame Director
Architect/Designer: Yapavi College Architectural Design Students and Staff

Specs:
Location: Chino Valley, Arizona
Completed: 2005
Cost ($/sf): $90/sq.ft (not including cost of student labor)
Size: 3202 sq.ft.

Construction:
Foundation type and R-value: Combination - slab on grade xps foam at edge (R-5), crawlspace ICF (R-16), basement integral XPS and blown in cellulose ((R-26.5)
Wall construction and R-value: 2x6 @ 24” o.c., 2” XPS and 5 1/2” unfaced fiberglass batt (R-29)
Windows: Double pane, low-e, argon filled. SHGC = .30 - .59; U- factor = 0.30 -0.35
Roof construction and R-value: Engineered trusses, blown-in cellulose (R-38)
Garage: Thermally and pressure isolated from living space

Energy specs:
Conditioning equipment : 14 SEER AC system, 56,672/80,960 BTU dual stage direct venting gas furnace
Water heating equipment: Solar domestic hot water, 40.9sq.ft. flat plate collector, 80 gal. storage tank w/ electric backup
HERS Rating: 90.5 (5 star +)

Water efficiency measures used in this project
· Low flow toilets, faucets and shower heads
· Water conserving dishwasher
· 1250 gallon rainwater collection system
· Gray water distribution system
· All hot water taps within 30ft. of hot water storage tank

Energy efficiency measures used in this project
· Whole-house Energy Star interior and exterior lighting package with CFL bulbs.
· Extremely tight building envelope (blower door test 0.96 @50 Pascals)
· Roof overhangs optimized for summer window shading and winter solar gain.
· Energy Star appliances including dishwasher, ceiling fans and ventilation fans
· Sealed ductwork, leakage measured at 0cfm @ 25 Pascals
· All ductwork is located within the conditioned space

Green materials and/or resource efficiency used in this project
· Decking, ICFs, wall and ceiling insulation all include recycled content
· Recycled cardboard and metal construction materials

Indoor air quality measures used in this project
· Balanced whole house air exchange system with MERV-10 and HEPA filtration
· All construction materials contain low or no VOC
· Low formaldehyde content in particleboard cabinets

Alternate Energy Utilization
Photovoltaic power: 2 KW (12 Shell 165w Powermax Ultra panels)
Solar water heating: 40.9sq.ft. SunEarth flat plate collector, Solaraide 80 gallon hot water storage tank/electric backup heater; cost $_________

Lessons Learned
In much of the country we pretty much take our abundant supply of clean water for granted, but a growing number of homeowners have to think twice before they wash their car or water their lawn. Builders in the Southwest have been dealing with this for ever, but pollution, climate changes and development pressure could make this a big concern just about anywhere. “Water could be the next expensive commodity for homeowners”, says Tony Grahame. He believes a whole system approach is necessary to make a real difference. Large rainwater catchment systems and separate grey water plumbing can eliminate the burden that landscape irrigation puts on municipal water supplies in this region, but efficient plumbing layout and low flow fixtures are just as important. This is one place where a little planning can reap big rewards without much expense.