Gladstone, in the heart of Halifax, is a mixed use development by Westwood Developments Limited, with two storey houses built close to the street and yards in the back. Just behind them, stand two luxury condos, St. Alban’s Mews and Wellington Court. After witnessing first-hand the benefits of architectural precast in earlier projects, Westwood decided precast was the material of choice for the exterior envelope on the two towers - and for a number of reasons such as speed, aesthetics, and reduced maintenance.
Speed - It seems that word is getting around about the speed with which precast panels can enclose the envelope of a building, and Canada’s short outdoor construction season makes that a major advantage. “Precast played a very important role for us in the delivery of the project,” says Daniel Chedrawe, Principal with The Westwood Group, "because we built the two 12-storey buildings — a total of 300 units — in 30 months from excavation to completion. Our weather in Halifax means that we have a building season of about seven months, and about six months of those are inclement weather."
When it comes to any building over six storeys, Chedrawe says, using precast helps immensely with scheduling, citing the fact that crews were able to erect the precast on the 12-storey building, that is over 200 feet long, in just 40 days. "Had we been doing a masonry building,” he emphasizes, “it would have taken a lot longer to close in the building and make it watertight, but precast enabled us to move on to finishing a lot faster to deliver the product to the market."
Precast manufacturer Strescon provided 475 pieces of architectural precast panels for the external cladding and curtainwall of each of the project’s two buildings, including three different types of panel; a seven and a half-inch thick architectural base panel, six-inch panels running up the building to the roof, and a cornice panel that finishes off the roof.
Aesthetics - The Gladstone buildings are visually striking, thanks to extensive use of precast. "We used a lot of reveals to create an articulated base that runs up for the first two floors," explains Dan Goodspeed, Partner with Kassner/Goodspeed Architects. "We incorporated a bunch of horizontal banding that became part of the visual of the building," he says, "with the three-storey base expressed, and then some strong banding and cantilevered details that run around the 12th floor to kind of put a top to the building mass, and then the top floor finish is beyond that, all of which were done in precast."
Although limited to one colour, Goodspeed says they used a variety of sandblast techniques to achieve different textures throughout the building. "It’s a pigmented finish using local materials in grey cement," says Strescon Plant Manager John Fraser. "There was a pigment added to the mix to give it a yellowish-golden colour," he adds, "and there are two different depths of sandblasting and a combination of reveals to give it some added character."
Less maintenance - Beyond its aesthetic merits, there was one other more pragmatic feature of precast that appealed to the Westwood people for this project: durability. “With brick,” says Chedrawe, "after 20 or 25 years you’re into re-pointing and those sorts of things, and if you do have issues with water penetration, it’s a lot more difficult to find them in a brick exterior — or any other exterior for that matter. With precast, it’s a much easier problem to solve partly because of the limited number of joints, and if properly detailed and constructed, most joints will last a lot longer than mortar between brick."
Not surprisingly, given the success of the Gladstone project — in addition to several other Westwood Group projects over the past few years that employed precast — Chedrawe has become a big fan. "Precast has come a long way aesthetically," he says, "and there are a lot of things that you can do these days with it, if you use a bit of imagination and if you have a good design team. Previously, precast panels were kind of dull and grey whereas these days we have a lot more architectural features like cornices and brick and stone patterns. In addtion, the sand-blasting you can do to expose the aggregate can give it a completely different look — there is a lot more variety in terms of what you can do."
And the Halifax skyline benefits from two new condo towers to prove it.
DEVELOPER: Westwood Developments Limited
ARCHITECT: Kassner/Goodspeed Architects
PRECAST CONTRACTOR: Strescon Limited