February 10, 2010

TRILLIUM PROJECT MANAGEMENT LTD.

The steel construction on the conversion of Strathcona’s Saint Francis Xavier School into a multi-family town home had to be done by hand because of space constraints.

Redevelopment

Steel provides solution in conversion of Vancouver heritage school

PETER KENTER

correspondent

When Vancouver property developer Take Root Properties took on the conversion of Strathcona’s Saint Francis Xavier School into a multi-family town home dwelling, it was presented with a unique incentive by the municipality.

If the heritage property was preserved, the developer could take advantage of its entire 5,000-square-foot historic footprint.

If demolished, zoning requirements would see the building’s footprint reduced by half.

A new skeleton of structural steel — most of it installed by human power alone — provided the solution to the project challenge.

“The building was constructed in the 1940s,” said David Hamilton, owner of Trillium Project Management Ltd. in Vancouver, the company hired to oversee the redevelopment.

TRILLIUM PROJECT MANAGEMENT LTD.

The existing building had to be lifted on jacks to allow the construction of the steel structure and a new foundation.

“It was originally a church, and then a school up until two years ago. We had to maintain the integrity of the building, including the building’s original roof line, to meet the requirements of a heritage property redevelopment.

“Although the original building was well-constructed, we now had to conform to the current building code, including the seismic requirements of new construction.”

The solution was devised during an extensive five-month pre-planning phase in consultation with developer Mark Sheih and Bruce Haden of HBBH Architects.

The contractor would place the entire building on jacks, raise it almost four metres and create a whole new support structure for the building, including steel girders and a brand new foundation.

“Raising it by that distance allowed us to move in mini-excavators and Bobcats to dig out a new concrete foundation that would support new steel beams and columns,” said Hamilton.

“After we completed the new foundation, the building was dropped down in exactly the same location.”

Working in a developed neighbourhood, the contractor had little room to manoeuvre the steel posts and beams.

The working area was too tight to make effective use of a crane, and the requirement to preserve the building’s roof made top-access impossible.

“We tried to get four or five steel contractor tenders on the job,” said Hamilton.

“When we explained that they would have to perform the steel construction by hand, none of them could put a price on it because it wasn’t something the guys in the estimating shop had ever encountered before. Because of the unusual nature of the job, we determined that this was just too much of an inconvenience for a structural steel company to take on.”

Instead, Hamilton chose framing contractor Bosma Construction of Vancouver for most of the installation.

“We ordered about $75,000 worth of structural steel from DDS Steel, rented the space in front of the street and used a crane with an 80-foot reach to lift it over the sidewalks,” said Hamilton.

“We then placed the beams on rollers and positioned and installed the steel by human power alone. It was very labour-intensive. Sometimes we had 10 to 12 people installing the heavy steel members.”

Beginning with welding the steel posts in the new foundation, the crew gradually built the new steel skeleton, a job that took about four to five months — although not all at once.

“It was a bottom-up renovation,” said Hamilton.

“We needed to deal with the property one floor at a time, so the steel framing work was spaced over the entire 14-month construction schedule. We had 16-foot ceilings on the first floor, but needed to achieve 10-foot ceilings on the upper floors. Since we couldn’t change the roof line, we had to drop the entire second floor by three feet, bolting in the new steel beams as we progressed.”

The addition of a structural steel catwalk on the exterior of the building will allow future tenants, including one unit zoned commercial, to access a rooftop deck.

Since load-bearing requirements are carried by the structural steel, each unit is designed to allow for flexible use.

“With its new structural steel framing, this conversion is now actually one of the safer buildings in town,” said Hamilton.

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