SIPs Construction | TC Legend Homes

Massey

by Senna | Apr 16, 2020

This 1,200 square-foot two-bedroom clerestory riverside home was built in 2020 in Ferry County, WA. TC Legend designed and permitted the home, and it was built by a Ferry County contractor.

The greater temperature swings associated with the continental climate led us to do a cost-efficiency study to choose the best SIPs panel thicknesses. Walls were bumped to 8 inches, yet the roof remained 10.25 inches. The exposed concrete stem wall footing stands high above the finished grade to keep the snow away from the panel toe, assisted by generous eaves and covered walks & porches, which also provide necessary shade during the hot summers.

An entry mudroom/utility room airlocks the house to minimize the entry of smoke during the fire season. Fresh, filtered air is delivered throughout the house via heat recovery ventilator (HRV), scavenging the heat from the waste air and imparting that heat into the incoming fresh air.

The circular windows are very easy to cut into SIPs panels; the trim-out is a bit more tricky.

Specifications

Fujitsu 9RL heat pump
Zehnder 220 HRV
Ground-mounted solar array for easy snow removal
8.25” R-38 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
Vinylek Boreal series triple-pane windows (U values between 0.14 and 0.16)

Whatcom County Net Positive Home

by Senna | Apr 16, 2020

This Built Green Five Star home in Whatcom County was selected as a Department of Energy 2019 Housing Innovation Award Winner!

The house is weighted south, toward the sun. With both asymmetrical roofs; longer to the south for solar build-out and a preponderance of south glazing for wintertime passive harvesting, the windows are appropriately shaded, with regionally appropriate eaves and porches, against summertime overheating.

The gross footprint of the house is rectangular, stretched with the long-axis running east-west to maximize space available for solar harvest on roofs and south wall, with much smaller east and west walls which overheat as they take the full force of the sun in summer. The slab-on-grade floor is finished to be left exposed and imparts a visceral, cooling, underfoot mass.

The slab also houses in-floor hydronic heating and radiates warm comfort during the long winter season, which, like all the seasons, can be felt and seen keenly in this house though the diversity of landscape views.

The home also features an open floor plan, with no wasted hallway space. The living area loft provides a sense of grandeur, but the modest-sized bedrooms and bathrooms require less energy and provide balanced efficiency.

SPECS/FEATURES

2707 Square feet (conditioned)
4 Bedrooms
2.5 Baths
SIPs construction
10.066-kW Solar
Triple-pane windows
Air-to-water heat pump
In-floor hydronic heating
Heat Recovery Ventilator
Electric car-charging
Low- or no-VOC products sourced throughout.
Wood posts, beams, counters, interior and exterior trim details milled on site from local timber

Photos by Scott Miller, Elevate Pro Photo

Victory Heights Net-Zero Home

by Senna | Apr 12, 2020

This Built Green 5-Star zero-energy home defines the Seattle eco-lifestyle. It features an open floor plan, heated hardwood floors, 9-foot ceilings, and exposed beams. On the roof, a 9.5kW net-metered solar array provides all the home’s power needs, and an electric car charging station is built into the garage. Triple-pane windows and SIPs construction offer plenty of insulation, and a whole-house filtration system keeps the air pure. Designer touches include Hinkley lighting, custom cabinetry, Carrara marble countertops, stainless steel appliances, an induction cooktop, and a 9-foot kitchen island.

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Whatcom County DADU

by Senna | Jul 18, 2019

All photos courtesy of Jared VanderGriend

This family needed some room for the big kids to spread out. TC Legend Homes designed and built this accessory dwelling unit to meet their needs. The family gained a large garage, with 576 square feet of living space perched above, accessible to the main house via 2nd-story bridge.

Key Features:

A simple design to minimize exposed surface area
Orientation and window placement to optimize passive solar
Insulated concrete forms
2nd floor Structural Insulated Panel construction (vice traditional framing) to reduce possibility of thermal bridging
Double-pane windows
High-efficiency mini-split heat pump for heating & cooling
Energy Star, EPA Indoor airPLUS, and 4-Star Built Green Certified
Home Energy Rating System (HERS) Index is 46. (A typical new home has a rating of + 62).

Toomes’ Bellingham Affordable Net-Positive Home

by Senna | Nov 6, 2018

Built by the TC Legend Homes/Powerhouse Designs team. We design and build. With a standard palette of materials & details that have been chosen, tested & refined over many houses, there is no confusion for the crew. The draftsman, engineer, and crew are consistent through all our projects, so everyone has done this system before.

Key Features:

Positive Energy – produces enough electricity to also power an electric car.
Energy Star, EPA Indoor airPLUS, and 5-Star Built Green Certified.
Honorable Mention in the Affordable Category of the 2018 US Department of Energy Housing Innovation Awards.
The home is oriented for both passive & active solar performance by facing south, as a rectangle with the long side (26’) running from east to west. The home is outfitted with an 8.1kw photovoltaic system.
Energy envelope includes structural insulated panels (SIPs). The 6.5″ Neopor R29 SIPs panel walls are locally made in Washington. Designed & engineered to reduce cold bridging by minimizing structural lumber & maximizing use of foam splines to connect panels. Shell is air sealed with triple beads of mastic at all joints and panels additionally taped at all joints. RIM joist insulated with R30 spray-foam at floor systems. Perfect rectangle box adds simplicity to construction & reduces corners & thus cost & air leakage.
4″ Extruded Polystyrene (EPS), a low VOC foam (R20), is used under-slab. The concrete slab-on-grade is exposed and is effectively a free finished-floor and a functioning thermal mass.
The heat recovery ventilator (HRV) is a Zehnder Comfo-air 200 which can scavenge 95% of the heat from the outgoing dirty air. Running through a class 4 filter (merv7/8) at between 29 and 118 cubic feet/ minute (cfm), the unit ventilates the whole house, extracting moist air from bathrooms/utility spaces, bringing fresh air into living spaces.
Energy Star appliances including a Geospring 50-gallon heat pump-powered hot water heater.
Stormwater from the roofs is infiltrated on-site using splash blocks below the gutter downspouts.
Home Energy Rating System (HERS) Index is negative 25! (A typical new home has a rating of + 62.)