FREMONT town-homes

Architecture Firm: 
CAST architecture
Completion Date: 
February 2009
Project Size (sf / site acreage): 
5 units 6824 sqft total, 5500 sqft lot
Project Location: 
Fremont Seattle
General Contractor: 
Don Ewing, Albion Group
Landscape Designer: 
Diana Hammer, Susan Black & Associates
Structural Engineer: 
Greg Coons, Swenson Say & Faget
Other: 
Tom Balderston Conservation Services Group - Environmental consulting
Owner: 
Marilyn Baylor, Holt Devlopment
SW aerial perspective
Sustainable Sites: 
We are working to create a vibrant development, with a deep green commitment. This five star Built Green project has recently been awarded a $10,000 grant from the King County/Seattle Built Green Grant for multifamily projects. This is an infill town house project in the Fremont neighborhood of Seattle. The site is split zone (L2 & C1-40) and is utilizing recent land use changes to increase the allowed density of the project from 4 to 5 units. The development is split into two structures, which helps modulate the massing from the street, and aid in the transition between the more urban pedestrian environment to the south, and the residential neighborhood to the north. While Seattle has seen a proliferation of pseudo-craftsman town homes, this project offers an alternative typology. A sophisticated approach to massing and honest use of materials, as well as a deep commitment to green initiatives, offers up a warm, modern set of dwellings. Open plans, floor to ceiling windows, combined with smart detailing, and a commitment to the environment, contribute to this projects integrated approach to thoughtful design and environmental sensitivity.
Toward Zero Energy: 
Each unit utilizes a radiant floor which will be heated with a 92% efficiency NY Thermal Trinity gas fired boiler system. These boilers will produce both the heat for the units as well as the domestic hot water, eliminating inefficiencies in standby heating, as well as the inherent redundancy and embodied energy of multiple systems. Solar hot water collectors will pre-warm this system, bringing the average efficiency to over 150%. Heat recovery ventilators are employed as whole house fans - providing fresh air while utilizing a high efficiency heat exchanger to extract embodied energy in the stale air to pre-warm incoming fresh air, greatly reducing the energy cost of providing air changes necessary to ensure high quality indoor air. The wall insulation for the town homes will be a hybrid of 2” spray in insulation, and 3 ½” formaldehyde free batt insulation. This produces a R-26 wall, and an extremely effective air seal. The ceilings will be an R-50 batt insulation, and the trusses we are using have an insulation heel allowing us to insulate the ceiling plane fully to the exterior walls.
Local and Sustainable Materials: 
The foundation and flatwork utilizes a 35% fly ash mix for the concrete. We will be using the first floor concrete slab as the finished floor, eliminating the need for an additional floor finish. The cladding is a mix of Hardipanel fiber cement siding and cedar tight knot rain screen. Hardipanel is produced locally, and made from non toxic raw materials, and is extremely durable. The cedar siding is regionally produced, and while renewable it’s use is measured within the project, to give scale, warmth and diversity. We have employed advanced framing concepts to minimize lumber waste. All but three shear walls incorporate twenty four inch on center studs. Structural headers have been integrated into the rim, which increases the insulation value, and reduces the overall quantity of lumber. Interior and exterior trim has been minimized by the use of a batten rain screen on the exterior, and a drywall reveal detail on the interior. These simple details equate to a huge reduction in the amount of interior & exterior trim being used in the project. Bamboo is being utilized for flooring and case work.
Sustainable Water: 
Storm water quality control starts during construction, by making sure that the best management practices that govern stockpiling of soil, silt fences, tire wash areas, are both implemented and maintained throughout the duration of the construction process. We have intentionally selected a builder to join our team who is invested in the environmental goals of the project. We are working on a hybrid storm water system which will allow for a substantial amount of ground percolation by running perforated pipe through a large gravel bed before entering the city storm water system. During a storm, water will spread out through the gravel bed and percolate into the soil below the drive. This will allow most rain events to be reabsorbed back into the ground. If an event overwhelms the under drive drywell, the overflow will follow its normal course to city storm water system. We have worked with the landscape architecture firm Susan Black and Associates, to reduce the watering requirements of the plantings by incorporating drought tolerant native plantings, with zero lawn area and spaced pavers patios to maintain permeability and reduce runoff.
IEQ and Comfort: 
We are utilizing radiant heat throughout the homes, which improves the air quality over forced air systems, while using less energy. Since we have no air handler associated with the HVAC system to use as a whole house fan, we are using heat recovery ventilators, which serve as both a whole house fan, as well as bath and laundry fans. This system ensures that there will be very little heat loss associated with providing fresh air necessary to maintain indoor air quality. All of the fiberglass insulation being used in the project, is formaldehyde free. Low VOC adhesives paints, and clear finishes have been specified from the framing through the finish work, including construction sealants, interior paints, and clear finishes for wood and metal surfaces. The Garages in all units are sealed from living space, and equipped with motion activated ventilation system to reduce the possibility of exhaust entering the house. No carpeting is being used in the units and cast in walk off mats are being provided at the entrance of every unit in an effort to further improve indoor air quality.
Collective Wisdom and Feedback: 
As part of our 5 star Built Green accreditation, we have been utilizing the services of Tom Balderston from Conservation Services Group (CSG) to do the verification of our application for Built Green rating as well as consulting on energy modeling, material specifications & systems for the town homes. We have had a series of on site meetings with CSG, CAST, the contractor, and relevant sub trades, to review design, detailing, and green goals. In addition to the onsite Q&A meetings we will be doing blower door tests to check for air barrier leaks, and a post occupancy evaluation, to learn from the owners how the details and systems are working. In terms of resources Built Green’s check list and associated handbook, have proved to be a very useful reference, helping ensure the environment is considered holistically within the project. This system requires benchmarks from categories of: site & water, energy efficiency, health / interior air quality, and materials efficiency. Additional online resources we have used on this project include buildinggreen.com’s greenspec suite of tools, and Suzanne Zuniga AIA’s information on alternative specifications at zuniga-arch.com.
Social Equity: 
The unusual nature of the site, with a sliver of commercially zoned area at its south side, inspired a much smaller unit size - which in turn corresponds to a more affordable structure. At only 10’ wide with a dynamic split level plan, this unit serves as a reminder that extraordinarily compact designs can also be extremely desirable, substantially more affordable and sustainable than the typical three bedroom three bath plan. With vaulted ceilings and twelve foot high windows, this 950 sq.ft. two bedroom two bath flat is a testament to quality over quantity. In the end, however, doing the right thing for the environment is very directly an issue of social equity on a global scale, people with the least, will be the first to feel the affects of global warming. Our client has pledged a 5% margin to the project, meaning that any item in the Built Green checklist which did not increase the cost more than 5% over the existing best practices was incorporated into the project. This has allowed us to include a surprising number of exciting ideas, details and materials which will give back to the community by using less materials up front, and energy over time.
Regional/Community Design: 
At the community level, this project is an infill project, located in the pedestrian neighborhood of Fremont in Seattle. Given the ability to shop work and socialize all within easy walking distance, there is an inherent environmental benefit to choosing to develop in a pedestrian neighborhood. While the zoning requires parking for each unit, the accessibility of the neighborhood encouraged us to design the garages in a flexible manner so they can easily be converted to a studio or office space if residents eschew the car for alternative forms of transportation. We are also including charging stations in each parking area to allow for the inevitable increased use of electric vehicles. We have worked hard to create a vibrant and modern development, with a deep green commitment. we hope it will serve as an example of how thoughtful design and sustainability can go hand in hand, and serve as an alternative typology to inspire other developers to move beyond the resource intensive, nostalgic neo craftsman typology has become the de facto standard style for Seattle town homes.