Multi-Family | Sonora, CA | SIPs Multifamily

Project Overview

Cooper's Hawk Terrace

S/F: 32’ x 72’ – each unit 2304 per duplex/1152 per unit

Panel Size: 6” GPS Walls/6” GPS Roof, over R-15 batts in the top chord of trusses

Why SIPs:  Premier SIPS provide superior insulation and air-sealing while eliminating the need to vent the attic, which is a big deal when it comes to the Wildlands-Urban Interface Code. Construction time was also a factor, as site labor is increasingly in short supply.

Innovative Design Elements: The SIPS over-truss construction allows longer spans while keeping some attic space for ductwork and fire suppression systems. The use of R-15 batts in the top chord of the truss beneath the R-28 SIPS panel gives us a well-air-sealed R-43 assembly, with no thermal bridging. Gable end walls go all the way to the bottom of the SIPS panel, which provides all the overhangs, without requiring additional framing.

Other:

• The total envelope heat loss for the duplex was 13,581 Btuh on the design degree day. This would represent an energy intensity of 5.895 Btu/sf.
• Each unit uses a Mitsubishi Ductless heat pump for heating and cooling and features a tier-3 heat pump water heater for domestic hot water.
• Vinyltek triple-pane windows were used, with low SHGC and a U-value of .16
• All appliances had the lowest energy use in their respective categories.
• 100% of lighting is LED.
• The homes were designed to receive maximum benefit from their passive design.
• Water heating, mentioned above, is at a Co-efficient Performance of 3.35

With solar panels on the garages only, these units will completely power themselves and the owner’s cars (two cars per unit at 10,00 miles per car per year). With the entire south-facing roofs fitted with solar panels, these 18 residential units would power themselves, AND an additional 54 average existing homes in the neighborhood.

Exteriors are all Hardi-plank, Hardi-panel, and Hardi-trim, for fire-proof exteriors. The roofs are all steel standing-seam roofing, for the same reason.   The finished floors are all dyed concrete.

The 6" GPS roof panels were set on standard trusses. There is no overhang on the trusses and no bird-blocking...only solid blocking between trusses in accordance to the Wildlands - Urban Interface Code. The bottom chord f the trusses provides a fully enclosed attic completely inside the SIPS building envelope, with only the ends of the trusses needing to be spray foamed.

The required sprinkler system is free to run along the bottom chord of the trusses. The combination of Hardi-Siding and Hardi-Soffit along with all the tempered glass in the windows and the steel roofing provides a fireproof exterior shell. This is something to be touted widely.

Ted Clifton Quote “PG&E, get out of our way!!!”

Coopers Hawk MultiFamily Project in Sonora, California chooses SIPs and wins multiple National awards.

• Project: Coopers Hawk Terrace, Multifamily Duplex, Sonora, CA
• Size: 2304 SF per Duplex or 1152 SF per Unit
• Builder: Delillo Contracting
• Designer: Zero-Energy Plans LLC

Awards & Accolades:

• NAHB’s Building Systems Council 2021 MultiFamily Winner
• SIPA Building Excellence Multi-Family Award
• Designed to US DOE Zero-Energy-Ready standard, as well as the EPA’s Indoor Air Plus program (thresholds for high indoor air and environmental quality)

Due to the speed of construction, high performance requirements, zero-energy (Title 24) mandate for new construction in the region and wild lands-urban interface code, Premier SIPS were the panels of choice for the building envelope of this multi-family project. This 18 unit complex was designed with ZEH (Zero Energy Home) principles at work. It also showcases the ideal blend of renewable energy and high performance construction.

Coopers Hawk Terrace incorporates a multitude of impressive design and energy efficiency features. Perhaps the most impressive is that each of the 18 residential units generates their own energy. With solar panels on the garages only, these units completely power themselves and the owners’ cars (two cars per unit at 10,00 miles per car per year). With the entire south-facing roofs clad with solar panels, these 18 residential units would power themselves, AND an additional 54 (average size) existing homes in the neighborhood.  This renewable energy source is a remarkable feat and true testament to the impacts of pairing renewable energy with sustainable construction.

With 6” graphite core(GPS) Premier SIPs, the project achieved superior insulation and air-sealing while eliminating the need to vent the attic.  For the Wildlands-Urban Interface Code, this was a big deal.  The thermal characteristics of SIPs also enabled the project to easily meet the Net-Zero energy requirements.

In addition to exceptional energy efficiency goals, construction time was also a factor as site labor was increasingly in short supply. Premier SIPS are pre-fabricated and engineered in a factory per the plans. This offsite construction allowed for delivery of panels ready to set and frame these structures in a matter of days rather than weeks.

Advantages of panelized construction include longer spans and created usable attic space for ductwork and fire suppression systems.  In the roof the use of 6″ R-28 SIPs with R-15 batts on top chord of the truss area created an exceptionally well air-sealed R-43 assembly – with no thermal bridging. The SIP roof eliminated  the need to vent the attic, which is a key in achieving the Wildlands-Urban Interface Code. Pre-cut gable end SIPs walls are pre-cut to fit at the bottom of the SIPs roof which provided necessary roof overhangs without requiring additional framing.

Tighter, well sealed, building envelopes mean better efficiency of heating and cooling resources. This also reduced the demand for HVAC (heating cooling and ventilation) systems, and allows these mechanical needs to be reduced. Each unit at Cooper’s Hawk Terraces used a Chiltrix CX34 air-to-water heat pump to supply both the heat, cooling, and domestic hot water, and an energy efficiency C.O.P. of 3.92 for heating, and 5.92 for domestic hot water. Which is exceptional for  performance.

Other energy-saving building materials included Vinyltek triple-pane windows, with low SHGU and a U-value of .16.  A ductless Mitsubishi heat pump was installed for heating / cooling and featured a tier-3 heat pump/water heater for domestic hot water.  Energy appliances representing the lowest-energy use in their respective categories, 100% LED lighting.

To further adhere with regional fire requirements, to best fire-proof the exterior, Hardie-plank was chosen for exterior siding panels and trim, along with steel standing-seam roofing and dyed concrete for finished floors.

The homes were designed to receive maximum benefit from their passive design strategies. Passive design takes advantage of the orientation of the sun, shade with overhangs, daylighting opportunities, window locations and site orientation to achieve maximum energy efficiency for a finished structure.

SIPs Recognition As A Superior Building System:

The recognition by NAHB & SIPA comes in addition to being named Green Builder Media’s Structural Brand of the year. Premier Building Systems strives to manufacture building systems and components that truly make a difference in our communities and is honored to contribute to highly acclaimed projects in the Construction Industry.