Worrell

Worrell

This 1,340 square-foot single-story, south-facing rural home was built for a professional couple in western Washington in 2018. It features an additional 576-square-foot attached garage to the north. The unheated garage, which sits outside the SIPs shell, is stick framed to reduce building and energy costs.

The home’s two offices are permitted as legal bedrooms, so it’s really a three-bedroom, two-bath net-zero rambler with a huge south-facing roof that has space for enough solar panels to power two electric cars and run the house.

Specifications

  • Department of Energy Net-Zero certified
  • Fujistu 9RL minisplit heat pump
  • 100% on-site storm water infiltration via 40-foot dispersion trench
  • 70 trees and 160 shrubs were planted that will grow a forest on site
  • 10.8 kW of solar panels installed
  • 6.5” R-29 SIPs walls
  • 10.25” R-49 SIPs roof
  • 4” R-20 foam under 4” concrete slab-on-grade for thermal mass
  • 5.5” foam (total) R-23.8 insulated concrete form perimeter stem walls
  • Vinylek Boreal series triple-pane windows (U values of 0.14 to 0.16)
  • 1:1.6 aspect ratio floor plan, with the long side facing south
  • Minimal east and west glazing

 

Trax

Trax

This 2,540 square-foot clerestory (one-and-a-half story) family house has an integrated, differently heat-zoned 1,040-square-foot garage and woodshop sitting within the SIPs shell. It was built in 2020 in western Washington.

A rigorous passive-solar window design uses the majority south-facing glazing for wintertime heating, shaded in summer by a shallow south porch and accurate south clerestory overhang. Multi-direction daylight penetrates and reflects deep into the connected main living space and second-floor balcony via the high second-floor clerestory glazing. 

Multiple cutting-edge HVAC and home-automation systems integrate to deliver low-cost air-to-water heat pump-based central heating, cooling, and fresh-air delivery, triggered via automatic carbon-dioxide and humidity sensors. Alexa-driven automated lighting and blinds are installed, a home-automation system that will expand in its capabilities as more options become available.

The clients’ requirement for a spacious first-floor master suite led us to design a smaller second floor in relation to the first. The clerestory design accommodates this layout by producing a daylight-rich one-and-a-half-story house.

Specifications

  • U.S. Department of Energy Net-Zero certified
  • Chilltrix CX34 air-to-water heat pump
  • Zehnder 550Q heat recovery ventilator (HRV), with in-line fan coil from Chilltrix
  • Development dedicated 1 acre of pastureland to a perpetual conservation easement, ensuring growth of native species
  • 12.4 kW of solar panels installed
  • 6.5” R-29 SIPs walls
  • 12.25” R-59 SIPs roof
  • 4” R-20 foam under 4” concrete slab-on-grade for excellent thermal mass
  • 5.5” foam (total) R-23.8 insulated concrete forms (ICF) perimeter stem-walls
  • Vinylek Boreal series triple-pane windows (U values between 0.14 and 0.16)
  • 1:1.6 aspect ratio floor plan, with long side facing south
  • Minimal east and west glazing

 

Columbia City

Columbia City

These two 2,250-square-foot, three-story family houses were built adjacent to each other, without garages, on a single lot in Columbia City, Seattle. The design preserved enough space for two spacious gardens.

This perfect urban lot has great southern exposure for passive and active solar gain. The small 25′ by 30′ footprints raised a surprising amount of internal space, but achieving net-zero performance, even with super-insulated SIPs panels, necessitated an enlarged south roof to house the required solar panels. We designed huge, cranked south roofs. This was a first for TC Legend, but they are now standard, architecturally a truly modem aesthetic response to the climate crisis.

The five-bedroom houses are planned to maximize common spaces and contain one un-programmed loft/rec-room space on each floor: space for a drum kit, a wine bar, a sewing room, or another TV room. Additionally the first floor has a big mud room to house bikes and camping gear and function as the storage space that a suburban house would normally have in the garage, which we eliminated in favor of gardens and uncovered off-street parking.

Specifications

  • Department of Energy Net-Zero certified
  • Chilltrix CX30 air-to-water heat pump
  • 100% storm-water infiltrated on site via two infiltration pits
  • 12.4 kW solar panels installed
  • 6.5” R-29 SIPs walls
  • 10.25” R-59 SIPs roof
  • 4” R-20 foam under 4” concrete slab-on-grade for thermal mass
  • 5.5” foam (total) R-23.8 insulated concrete forms (ICF) perimeter stem walls
  • Plygem triple-pane windows (U values between 0.21 and 0.24)

 

Larson

Larson

This 2,020 square-foot two-story, five-bedroom family house was built in rural King County. It has an additional 280 square-foot integrated single-car garage within the SIPs shell. The garage can be re-purposed into a flex space, such as a kids’ TV room, playroom, workshop, etc. The home was built in 2018 in western Washington.

The major challenge with this undeveloped site was to dig the potable water line 1,000 feet through a boulder field. The client miraculously located the well stub within the forest, and the TC Legend team dodged and weaved the waterline through.

Additionally, we carved the driveway 500’ through the second-growth forest, located the house for optimum solar exposure, and laid the power line in the middle of the driveway, with septic adjacent under what will likely become a forest lawn. A truly stunning site with stag deer, bear, cougars, and more.

The wrap-around porch with concrete walkway mediates between the inside and outside, with a front mudroom to contain kids’ messes and offer an airlock to prevent large temperature drops when the front door is opened in winter.

The house was prevented from becoming overly large and expensive by sizing the kids’ bedrooms at kids’ scale: on the small side of things. However, the vaulted SIPs ceiling at the second floor, which is a standard feature of SIPs construction, presents a very spacious overhead feel. Additionally, multiple windows in many bedrooms ensures that the kids rooms don’t feel boxy.

Specifications

  • U.S. Department of Energy Net-Zero certified
  • Fujistu 18RLXFG heat pump with multiple fan coil heads
  • 12.4 kW of solar panels installed
  • 6.5” R-29 SIPs walls
  • 10.25” R49 SIPs roof
  • 4” R-20 foam under 4” concrete slab-on-grade for thermal mass
  • 5.5” foam (total) R-23.8 insulated concrete forms perimeter stem walls
  • Euroline triple-pane windows (U values from 0.14 to 0.18)
  • 1:1.6 aspect ratio floor plan, with long side facing south
  • Minimal east and west glazing

 

Chappell

Chappell

This 1,950 square-foot, two-story, 3-bedroom family house was completed in Seattle in 2018. It has a two-wall carport adjacent to the back door.

The project presented a challenging permit process for the TC Legend office and a complex dig: The undeveloped lot was located atop a known landslide area, requiring deep pin piles and extensive geotech involvement. A heavily protected 6-foot-diameter seqouia tree stands beside the only site entrance and was successfully cared for during the extensive dig, with drain lines threaded through the roots, dug by hand.

With the main hilltop vista facing west, the challenge was to have the house embrace the view without overheating in the afternoon sun. Retaining the deciduous western tree cover was essential, as was ordering the western windows with low solar-gain coatings.

The storm-water system was not allowed to point-discharge onto the steep slope. The extensive use of permeable pavement ensured the trees and shrubs remain watered, stabilizing the slide-prone slopes.

Specifications

  • U.S. Department of Energy Net-Zero certified
  • Chilltrix CX34 air-to-water heat pump
  • Zehnder 350 HRV
  • 10.8 kW of solar panels installed
  • 6.5” R-29 SIPs walls
  • 10.25” R-49 SIPs roof
  • 4” R-20 foam under 4” concrete slab-on-grade for thermal mass
  • 5.5” foam (total) R-23.8 insulated concrete forms perimeter stem-walls
  • Euroclime triple-pane windows (U values between 0.14 and 0.18)
  • 100% rainwater-permeable driveways and walks