SIPs architect

The drive to energy efficient architecture and sustainable house design has created fervour for Structural Insulated Panels or SIPS construction.  SIPS is one of the best ways for a SIPs Architect to design a high performing energy efficient house design.  A secondary benefit is that SIPs are structurally sound and can carry the live and dead loads of the structure.  SIPs enables significantly longer spans in walling, flooring and roofing without secondary bearer/beam support.

The benefits and challenges of SIPs for a SIPs Architect are readily apparent.

SIPs Higher Energy Efficiency.

The R value of SIP’s of between R-15 to R-55 and far superior to traditional structural timber framing.  SIPs are factory fabricated with a foam core sandwiched between two layers of timber or metal sheaving.  The internal controlled environment for manufacturing of SIPs ensures consistent precise panel joints which results in air-tight joints.  An airtight building with better insulation requires a smaller HVAC system to maintain a comfortable ambient air temperature. Structural Insulated Panels joints ensure an airtight envelope, increases energy efficiency and therefore reduces utility costs during the building’s lifecycle.

SIPS Reduce Condensate.

The panels are manufactured in controlled factories by laminating a insulated foam core between two layers of oriented strand board (OSB).  SIPs architect Threadgold Architecture + Construction preferred SIPs manufacturer incorporates two layers of plywood rather than OSB.  Structural Insulated Panel joint detailing reduces uncontrolled air intrusion and thermal bridging that creates condensation, mildew and mold.  Panels are fabricated in an offsite factory controlled environment and therefore also less exposed to weather during the construction phase.

Shorter Construction Program.

The prefabricated manufacturing process ensures SIPs meet the exact site dimensions which guarantees rapid on-site assembly.  More efficient erection on-site reduces construction program which contributes to lower labor rates and builder interest payments.  SIPs are fabricated to size and then shipped ready to assemble, reducing onsite labor costs by 55%.  The reduced construction program on-site assists the SIPs architect with fewer weather related delays and contractual Extensions of Time.

Ambient Air Temperature.

An airtight building ensures fewer opportunities for outside air to ingress the building envelope and affect indoor air temperatures.  The air-tight external building envelope reduces air infiltration and the resultant allergens carried by that air.  The resultant consistent interior ambient air temperature, enhanced occupant comfort levels and healthier environment.  The smaller seasonal temperature fluctuations reduces probability of condensate forming and therefore mold and mildew.

Environmentally Sustainable Design.

The engineered timber in the SIPs plywood or OSB comes from renewable sources. Additionally, the factory fabrication and shop drawings ensure less onsite waste in the manufacturing waste.  SIPs can generate up to 70% less construction waste than traditional steel or timber framing.  Recycled or low-VOC materials utilized by some manufacturers also contributes to greater sustainability.  These attributes, combined with greater energy efficiency, reduced utility consumption reduces a building’s carbon footprint.  Traditional timber framing is assembled onsite and creates considerable construction waste from imprecise cuts and mistakes.   The precise measurements and shop drawings of SIPs customized each project results in reduced construction waste hauled to local landfill.  These SIPs features ultimately reduce the embodied energy of the architectural design of the building project.

Building Services.

The SIPs architect is presented with some pragmatic design challenges in SIPs construction.  To maintain the structural integrity of SIPs panels, the conduits for electrical wiring requires pre-drilling during fabrication.  Further, a roof constituted by SIPs panels can’t accommodate recessed light fittings as it compromises the panel span.

Water reticulation piping should be avoided on exterior walls if possible. Alternatively, it is common practice to fix furring channels to interior SIPs panel to accommodate hot and cold water reticulation.

Mechanical air-conditioning/HVAC can also compromise the structural performance of SIPs panels.  Mechanical flexible and rigid ductwork and plant is typically installed in ceiling cavities to underside of the roof.  A SIPs architect has to find new ways to accommodate mechanical air-conditioning to distribute cool airflow.  A SIPs architect will commonly incorporate drop plasterboard ceilings to accommodate air conditioning ductwork.