Architecture Firm:
Mary Louise Vidas, designer
Completion Date:
Anticipated completion date July, 2008
Project Format (not yet built / built):
Under construction
Project Size (sf / site acreage):
2243 sf/ 6134 sf
Project Location:
Bend, Oregon
Budget ($/sq Ft, optional):
$200/sf
Interior Designer:
ML Vidas
General Contractor:
SolAire Homebuilders
Landscape Designer:
Heart Spring Designs
Lighting Consultant:
Globe Lighting
Structural Engineer:
Sandy Charon, Charon Engineering
Mechanical Engineer:
Mountain View Heating
Owner:
ML Vidas & Allan Staley
Sustainable Sites:
The Staley-Vidas Residence is located in the mixed-use neighborhood of Northwest Crossing, formerly the site of a tree farm. Existing native vegetation has been protected where feasible, including the preservation of a mature ponderosa pine tree. Volcanic boulders uncovered during excavation have been stockpiled for incorporation into the landscaping. The exterior color palette of rust-red and warm rose derives from the colors of ponderosas and local basalt.
Vidas used the traditional Prairie style to demonstrate how a familiar form can become extraordinarily energy and resource efficient. Wide 4’ eaves allow protection from overheating in summer, while the eaves at south-facing windows are shortened to 24” to bring winter sunlight deep into the house. From the interior, views are framed to strengthen connections to site features. The ponderosa is visible from the master bedroom and from both windows in the upstairs bathroom. Local landmarks, Mount Bachelor and Broken Top, are each framed by select west-facing windows.
The harsh high desert climate demands special attention to outdoor spaces. The layout of the house forms three distinct outdoor areas: the fully sheltered front porch, the semi-private patio and the fully private master bedroom garden. The partially shaded patio receives ample morning light and is protected from late afternoon heat.
The landscape design works to restore and re-establish native habitat for birds and small woodland creatures. Plant material has been selected for its fruit bearing capacity. Although the lot is small, areas along the west property line and in the northeast corner have been set aside for un-manicured growth. As the neighborhood gets built-out, these pockets of habitat will become even more important to fauna.
Toward Zero Energy:
The most pronounced energy measures will be obscured from view when the house is complete, but their effectiveness will endure for the life of the building.
SolAire, the contractor, installed AtticWrap, an innovative Tyvek product, as part of the roof system. AtticWrap is a vapor-permeable air and water barrier that allows attic moisture to escape through diffusion while stopping airflow. SolAire requested a blower-door test to field measure the benefits of AtticWrap. The house out-performed a standard Earth Advantage house even before insulation and drywall had been installed.
SolAire has been diligent about maintaining good construction practices. Wall penetrations have been sealed and caulked. Staggered stud wall framing (8” plate) with blown-in-blanket insulation will yield R-38 walls. The slab-on-grade is fully insulated with 3” rigid insulation for R-15. The hip roof functions like raised-heel trusses for R-50 attic insulation.
The house is sited for winter solar heat gain, especially into the Sun Room. French doors and an operable window control heat from the Sun Room into the house.
A high-efficiency gas boiler fuels the hydronic in-floor heating system. The whole house ventilation system includes an energy recovery ventilator to extract heat from stale air before exhausting it to the outside. A 4’x10’ solar collector is expected to provide over 50% of the annual hot water needs. A 2.1 Kw photovoltaic array will 2,709 Kwh annually, qualifying the home for an Energy Trust of Oregon $4200 incentive. The project achieved an HERS rating of 46.
Strategic placement of operable windows provides for varying degrees of cross ventilation and night cooling. No air conditioning will be installed.
Local and Sustainable Materials:
A house built in the Pacific Northwest should utilize the indigenous building material: wood. This house uses FSC-certified framing from Warm Springs Forestry Products, less than 50 miles from the building site. Countertops by Paperstone are another local product. Durable materials include fiber-cement siding, tile and wood flooring and concrete pavers.
A salvaged double-hung window between the Sun Room and the Living Room extends daylight into the house.
SolAire has minimized construction waste and is documenting the jobsite recycling.
Sustainable Water:
Water quality is protected with full on-site storm water management. The landscape plan incorporates swales and dry creek runs at the roof drip edge to direct rainwater to landscaped areas. No irrigation will be installed.
Potable water use is reduced with high efficiency fixtures throughout the house.
IEQ and Comfort:
The livability of a small house is greatly enhanced by the room layout. Vidas used architectural features to define public, semi-private and private spaces with varying degrees of transparency. For example, the dining area has a coved ceiling with recessed LED rope lighting. The open floor plan promotes views across this space while the ceiling delineates the dining area.
Additional definition of spaces allows ‘refuge’ and ‘prospect’. Refuge is the sense of protection and shelter; prospect is the ability to watch and see. A sense of security comes from having both. The window seat in the dining area provides comfortable seating in the between space at the edge of the living room-kitchen-great room. The window seat at the stair landing is further situated between the upstairs and the downstairs, and between inside and outside. The Sun Room is proportioned for comfortable seating for one or two people and is adjacent to the larger living room. The Office extends the living room area or pocket doors can be closed for greater separation.
High bedroom windows bring in daylight without compromising privacy.
Electric lighting includes LED recessed cans in high use areas and dedicated fluorescent fixtures in utility areas. Compact fluorescent bulbs are used throughout the house.
Residential acoustic problems usually stem from three sources: outside noise, internally generated mechanical noise, and adjacent rooms. The added insulation improves the overall quietness of the house. The Mechanical Room is physically separated from all sleeping areas and all sleeping areas are separated from each other. The upstairs bedrooms are adjacent but separated by closets. Interior insulation was added at the Laundry Room to decrease noise transfer into the living spaces.
Indoor air quality is achieved by an integrated system of hydronic in-floor heat and whole house ventilation with an ERV. Thermostats in each of eight zones regulate heat. Zero VOC paints, finishes and sealants have been used on the interior. For additional air quality, the house has no carpet, a central vacuum system and a motion-sensor garage exhaust fan.
Collective Wisdom and Feedback:
The success of this project lies in the integrated design approach used throughout the design and construction process. The designer/owner/contractor team has been able to investigate issues and develop solutions. During schematic design eco-charrettes were held focusing on different issues: site and solar access; solar integration of the hydronic system; landscaping, stormwater and native plants; and local low VOC materials. Monthly construction team meetings have effectively resolved problems early.
This project is registered with the USGBC LEED for Homes Program and Earth Advantage; a Platinum rating is anticipated. The LEED process encourages 3rd-party testing, providing reliable feedback on design values. The homeowners will install a weather station with computer interface to monitor the building’s energy performance. The PV array has an integrated data recording system. One manufacturer, Eco-Timber, is using this house to test a new product, woven bamboo flooring, to see how it performs over radiant heat in the high-desert climate. At 3700’, the Central Oregon climate experiences wide daily and seasonal temperature extremes with frequent low humidity. Performance data in this climate zone will be a valuable resource to local and regional builders and designers.
Regional/Community Design:
People outside the green building community often assume there are only two lifestyle choices in sustainable residential design: the tree-hugger earthy type or the techno-savvy ultra modern urbanist type. The Staley-Vidas Residence is a clear example of another option. Starting with a traditional style and integrating the building systems can produce a highly energy efficient, yet pleasantly comfortable, house.
This project was begun as an experiment to explore cost effective measures for residential sustainable design. The publicity around the LEED-H and Earth Advantage rating on this project will initiate public awareness. Additionally the house will be open for viewing for two weekends as part of the Central Oregon Builders Association Tour of Homes. The project will be submitted for the Central Oregon Green + Solar Homes Tour in October, 2008. Vidas held an Open Wall Open House, inviting members of the design and construction community to view the house before the walls were enclosed; nearly 50 people attended. As actual performance data is collected on the house, information will be shared in local and regional workshops and publications.
