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The benefits of steel for residential construction
by Story: Julia Preston & Photo: Brendan Burden
Steel is the go-to material for industrial and commercial construction. But when it comes to residential projects, steel is underrepresented. Jay Lim, principal at 25:8 Architecture + Urban Design in Ottawa, is working to change that.
“We have been huge proponents of steel for our cladding…
on our residential projects,” he explains. “We have found
that it is an efficient, economical and environmentally
Over the past several years, Lim and his team have used steel
to clad residential homes and also for structural elements within
The BAM house (an acronym formed from the clients’ names)
is what Lim calls a “typical 1950s post-war design”. It has two
small bedrooms and one bathroom. The young couple who own
the house were keen to make it bigger and family friendly. Enter
Lim and his team at 25:8. “They wanted to make the house a
bit more contemporary. They were very progressive,” says Lim.
“We chose all white for the exterior because of the
The white ribbed metal cladding covers the roof and walls of
the entire house and has a high albedo, which means it reflects
substantial amount of sun and heat. High reflection results in
lower summertime cooling costs.
The renovation involved adding dormers and a signature 25:8
element, the cape, an extension of the roofline over the front
door. This provides protection and privacy at the front of the
house. The firm used warm wood tones and trim inside the cape
and dormers to provide a natural element to balance the strong
industrial lines of the steel.
For Lim, the benefits of using steel are four-fold: economy,
efficiency, environment and aesthetics.
“Our clientele that come to 25:8 tend to have the same kind of
mission objective. They all like design. They don’t tend to have
huge budgets. So they’re willing to let us be very creative,”
he says, “One of the ways we’re able to manage costs is by
managing the number of trades on site and getting bulk orders,
and steel allows us to do that.”
Lim usually selects corrugated siding profiles that can be used on
both roofs and walls. By using just one material, installation can
be handled by one trade; there is also less over-ordering and less waste. Lim estimates that this approach saves 20 per cent on trades. Additionally, by purchasing a larger order of material, the unit costs are reduced.
Steel is also speedy to install. Because they come in large sheets
putting up cladding is much faster than masonry or siding. This
reduces the time framing is exposed to the elements and allows
construction to progress quickly.
Sheets of steel can also be precut at the factory to the specific
lengths needed. This limits the amount of work required onsite.
When cutting is required, such as around trim or corners, a
circular saw with a carbide blade will do the trick—no special
tools are required.
The finishing details, like trim and flashing, are another plus for
Lim. “It’s all the same stock. It’s the same thickness of metal. The
colour is going to match exactly the same. It allows us to get the
custom profiles we want. What we love about the metal flashing
is that we can get really sharp, clean edges versus some other
stuff out there. I love the customization of the flashing. We’ve
done a lot of interesting profiles to make the edges look even
thinner than they actually are. I think that’s a huge benefit.”
Among builders, designers and homeowners, there is a growing
awareness of the environmental impact of construction and
various building materials. Lim notes that while metal can have a
high carbon footprint at the manufacturing stage, its overall life
cycle impact is the most sustainable choice.
“The fact that you don’t have to do anything with steel for 40
years means that there’s a lot less labour and cost involved in
that,” he says. “And at the end of the life cycle of this product,
if we have to replace it, we’re going to take it down and recycle
it. Whereas with asphalt shingles they’re just going to the trash.
Vinyl siding is going to the trash.”
Aesthetically, 25:8’s designs tend to have a modern, industrial
style. Metal is a key component in achieving that look.
FOR OVERALL LIFE CYCLE IMPACT HE FEELS METAL IS THE MOST SUSTAINABLE CHOICE.
The ribs of the corrugated sheets reinforce the modern
architectural geometry and using one colour gives a monolithic
look. But the ribs also follow the ‘traditional’ forms of the
houses, like gables or dormers. Steel helps to balance the old and
new in many projects.
For the ONE368 project, 25:8 renovated a 100-year-old
home. Much of the work focused on returning to the house to
its original state—reopening doorways that had been closed
up and enlarging the front window to its former size.
Systems and finishes were updated throughout the interior, but the original floorplan was maintained. The original structure was one and a half stories with a pitched roof; however there had been several additions over the years, each using different materials
Lim explains, “It just looked very disparate and it didn’t connect
well. So we decided to clad it with all one material… The steel
helped unify the building. [It also] allowed us to get the profile
of the original house to keep that aesthetic of this traditional
neighbourhood, but it obviously was something very new
Here, Lim chose black siding with wood accents. He says, “The
great thing about metal is that it’s robust and industrial looking,
but that’s also the downside.” To give his designs more of a
neighbourhood feel, he often incorporates wood and other natural elements to bring a bit of warmth to the façade.
While the ONE368 project challenged Lim and his team to unify a building with old and new elements, the Winona project called for the opposite: to obviously distinguish between old and new.
The original house was a small bungalow; the renovation added a
second floor and other additions. Lim decided to “pay homage” to the original structure by cladding existing sections in white and running the siding vertically. On the new additions, he used black cladding run horizontally. “The white was what we call the ghost of the original house.”
Winona also employed steel as a structural element, using beams and columns to support cantilevers and balconies. “The metal…made the building look more dynamic, very modern and sleek.”
Thin round columns appear almost delicate relative to the building. In the front they nearly disappear, making the cantilever look more dramatic. Lim notes, “We could not have done that with wood. The wood would have been much thicker and it would have been much more intrusive.”
Lim also cites that prefabricated trusses, normally used in factories or warehouses, are beneficial for residential construction. “If you want that clear span, that’s the way we do it,” he says. “It’s an economical way. It’s prefabricated so we know they fit. Maybe it looks a bit like a barn, but once we clad it, the way that we do our architecture, it works out really well.”
“When we want to do dynamic structures, like a large cantilever,
steel becomes really valuable. Because of its strength to weight
ratio we can get longer spans, use less material. It hides, so in that case we’re not showy with steel, but it’s playing an integral role in doing the architecture that we need.”
Lim notes that there are some challenges using steel in residential construction. For cladding that is riveted together, he emphasizes that proper waterproofing is essential.
Another challenge can be finding tradespeople who are open to
working with steel as opposed to other more traditional materials that they may be more experienced with. “They’re so used to using a hammer and nails. You have to be able to coach them into saying yeah, this is the appropriate application for steel,” he says.
“We could not have done that with wood. The wood would have been much
thicker and it would have been much more intrusive.”
Lim also admits that it’s not always easy to get clients to recognize that steel cladding can be the right material for their needs. “If you’ve only ever been exposed to clapboard siding and wood shake shingles then this looks completely bizarre to you.”
Lim feels that the more steel is used in residential construction, the more popular it will become.
“We’re using steel in a non-traditional way, but we’re doing great
architecture. Just because it’s industrial doesn’t mean it has to be purely functional.”
Whether it’s prefabricated components, buildings made out of steel, steel frame structures or steel cladding, there are many possibilities for metal in residential construction. The result can be innovative, functional and attractive structures that are suited to the people who live there.