March 6, 2010

BC HYDRO

A new BC Hydro building in Port Alberni B.C. is aiming to use a quarter of the energy of standard buildings.

FOCUS | Green building / LEED

Port Alberni BC Hydro building shooting for LEED Gold

JESSICA KRIPPENDORF

staff writer

BC Hydro is heading for higher ground with the construction of its new 23,000-square-foot facility in Port Alberni. The development is shooting for LEED Gold certification and is aiming to use just a quarter of the energy used in an equivalent building built to current market standards.

The $10 million project should improve service to 16,000 residential and business customers on the West Coast of Vancouver Island, including Port Alberni, Tofino, and Ucluelet.

The single level with mezzanine will include office and warehouse space and replace a 40-year-old, 14,600-square-foot facility located in a provincially-designated tsunami zone.

“The district office needs to be able to function as an emergency operations centre whenever required to do so – one of the primary reasons that the existing district office in Port Alberni was not renovated,” said Ted Olynyk, BC Hydro's Vancouver Island manager of community relations. 

A passive, high-performance building envelope and high thermal value glazing systems will assist in meeting the proposed energy target.

Two basic rainscreen wall systems make up the building’s exterior – the first is comprised of exterior wood cladding over strapping, installed on Z bars, which creates a vented air space. Spray-applied polyurethane foam insulation forms an air and vapour barrier, and is placed on glass faced gypsum sheathing with metal stud framing and finished gypsum board interior.

“The thermal performance of this wall assembly is R-24 for the heated spaces like the office areas and change rooms and R-18 for the semi-heated spaces like the truck bays and workshops,” said Olynyk.

The second wall system has split-face concrete block cladding, air space, and spray-applied polyurethane foam insulation on glass faced gypsum sheathing, with metal stud framing, and finished gypsum board interior. Thermal performance of this system is the same as the first.

“The building has a concrete slab on grade with a concrete grade beam perimeter and pad footings for the columns,” he said. “High compressive strength rigid insulation, under the concrete floor slabs with a vapour barrier between the insulation and the concrete slab, supplements a floor-slab radiant heating system.”

The outside face of the concrete grade beams and footings of the building have rigid insulation with concrete parging to complete the building envelope system.

Glazing is provided by a high-performance thermally broken curtain wall system with a built-in, engineered, rain screen drain design. The frames have a clear anodized finish and have operable units throughout.

“The sealed air-filled glazing unit will be a four element system with glass on the exterior and interior planes and two interlayers with a low-e coating to reduce solar gain,” explained Olynyk.

Hydronic radiant heating and cooling systems, along with a hybrid of natural and mechanical ventilation and a 100 per cent dedicated outdoor air system, with exhaust air heat recovery, also help conserve energy.

Solar water systems contribute more than five per cent of its energy requirements.

The first of three roofing systems is a green roof, which covers 40 per cent of the building and is situated over a typical SBS roofing membrane. A smaller area of flat roof over the office areas will be of standard low-slope roof construction using a LEED-compliant cool roof membrane.

The remaining roof area will receive a standing seam metal roof, which will also meet cool roof requirements.

The design is meant to embrace B.C.-inspired imagery.

“The arch of the building’s roof is symbolic of wanting to draw all employees together under a unifying form,” said Olynyk. “

It could also represent a breaching whale or leaping salmon. The volume generated by the curved form assists with a passive design approach, as it relates to daylighting and energy utilization.

The use of wood, both for the interior and in cedar shingles on the exterior, relates to B.C.’s forest industry and complies with the provincial government’s Wood First Act.

The project has been divided into 28 trade packages, about a third of which have been awarded. This includes site clearing, earthworks, flexible paving, concrete, structural steel, glu-lam timber, mechanical, electrical, and geothermal wells.

Vancouver’s Omicron is acting as design consultant and construction manager, and is providing interior design and engineering services.

The project is scheduled for completion in late 2010.

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