Cambridge’s historic City Hall is getting a makeover. Judging by the exterior condition of the 152-year-old building, one might think the project would be a straightforward one. The structure looks solid and the stone façade appears to be in good shape, however the project has posed some challenging surprises for contractors.
Custom fabrication just one of project’s challenges
Cambridge’s historic City Hall is getting a makeover. Judging by the exterior condition of the 152-year-old building, one might think the project would be a straightforward one. The structure looks solid and the stone façade appears to be in good shape.
But renos and restorative work to the 16,500-square-foot heritage hall are not without their challenges, says project manager Jim Hughes of Kitchener-based PM Contracting Limited, the general contractor.
The project — the last of a three-phase Master Plan redevelopment — includes: revised entrances on the ground and second floor, including new stairs at the exterior of the five-storey tower that fronts the three-storey main building; relocation of elevator and new associated lobbies; new archive offices; a fully renovated third floor council chamber including an updated audio-visual network and restoration of all exterior windows. Throughout the building, original plaster walls will be restored where feasible
It is “very challenging” to co-ordinate schedules for the subtrades and consultants to keep the project moving on time, explains Hughes.
During interior demolition this spring, construction crews found materials and construction that weren’t in drawings available to PM Contracting at the time of bidding. “There is a lot of custom fabrication on site to make sure things line up and fit.”
The old city hall has undergone many renovations over the years, the biggest being in 1965 when an elevator was installed in the tower which features the oldest operating clock in Ontario. The elevator will be relocated to the main building so the design/building team can re-establish the original main entry to the hall through the tower.
Fortunately, demolishing the old elevator core has been straightforward because it wasn’t tied to the existing structure. However, cutting through walls and floors to make way for the shaft’s new location has revealed a few construction surprises that weren’t in any drawings, says Hughes.
The old framing, for one, is not to standard size so carpentry work on site is required to fit the shaft into its new location. A temporary support structure consists of jackposts and aluminum shoring beams. The replacement structure will contain laminated veneer lumber (LVL) beams.
The original design had staircases flanking either side of the tower from grade to the second floor. To conform to modern building code standards, the replacements — metal stairs with glass balustrades — won’t look like the old ones but they will match the design of a second-floor glass pedway linking the heritage hall to the new administration building. The pedway and administration building are previous phases of the city’s Master Plan.
Door and window openings on the old hall which were changed over the years will be returned to their original locations. Previous renovators had the foresight to save old stone they removed and store it on site, making the work easier for PM Contracting, says Hughes.
The old wood windows will be removed, repaired and restored off site by Twins Painting & Decorating Co. Ltd. Some of the original doors will also be restored while reproductions of the original front entry will be made by PG Heldmann Woodworking Ltd.
Rather than gut the entire interior spaces, the lead architect on the project, E.R.A. Architects Inc., decided to save some elements of the 1960s renovation, including a circular staircase leading from the main vestibule to the second and third floors, says Robyn Huether, project architect.
“We feel the renovations over time create a narrative for the building, so often our practice is to maintain certain aspects of various past renovations.”
The second floor makeover will feature a public gallery and offices while the third floor will offer city council fanciful chambers that include updated audio-visual equipment. Ceilings will be opened up to make way for the installation of “miles of conduit,” says Hughes. “It’s been quite a challenge for our electrician to find the space to run the entire conduit.”
A customized HVAC system is required on the third floor to meet the heating and cooling demands of a space with 20-foot ceilings. To circulate air in the space requires large equipment that will be installed at the corners of the third floor behind partitioned walls. “The architects (Diamond + Schmitt Architects Inc.) have worked out details to make it look pretty,” says Hughes.
Due to the nature of the work, the contract comes with a sizable contingency fund —“a little over 10 percent,” says Hughes. Bidding on this type of work should strictly be done based on the drawings and specs provided. “You can try and guess things and budget for problems but you could outbid yourself and not get the job.”
Construction started in April and is slated for completion next January at a cost of just over $2.6 million.