How do I match the exterior of a second-storey addition to my existing Ottawa home?

A second storey can look like it was always part of the house, but it takes deliberate planning. A designer who pays attention to your home's materials, proportions and roof form makes the biggest difference.

Cladding is the most visible element. If your house has brick, matching colour, size and mortar joint is the goal, but brick changes over decades and your exact brick may no longer be made. Salvage suppliers sometimes have matching older brick, and a mason can source close matches. If an exact match isn't possible, a deliberate change, such as brick on the main floor and a complementary siding above, can look intentional rather than mismatched. Ask for samples next to the existing wall before deciding.

With vinyl or aluminum siding, matching is often easier, but profiles, exposure widths and colours vary, and faded existing siding may not match new material. Some owners re-side the whole house during the project for a uniform look, which can also be a chance to add exterior insulation. Engineered wood and fibre cement are other options. Get the cost of partial versus full re-siding as separate quote lines.

Windows should relate to the ones below in size, proportion, style and muntin pattern. Mixing window types or frame colours between floors creates an obvious mismatch. Ask your designer to set a consistent window pattern for the whole facade, and choose glazing suited to Ottawa winters, which regularly reach well below -20°C.

Roofline matters more than any material. A box sitting on top of the old roof form rarely looks right. Matching roof pitch, eave depth and fascia proportions helps the addition read as part of the original house. If the roof style changes, it should still be coherent with the house.

Trim and details, including corner boards, soffits, fascia and even downspout colour, all add up.

In neighbourhoods with distinctive character, design guidelines may come into play, and if your property is designated or in a Heritage Conservation District, the City must approve alterations, including additions. Your designer should confirm that early.

New walls must meet current energy rules; the Code's addition table calls for R-19 plus R-5 continuous insulation in above-grade walls, unless a compliance package is used. That can make new walls thicker than the old ones, and a good designer handles the difference without visible jogs. You can browse addition contractors in the Ottawa Construction Network directory and compare itemized quotes.

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Looking for experienced contractors? The Ottawa Construction Network connects homeowners with qualified professionals:

• Homeupgraders
• RenoMotion Inc.
• Eastern Residential Solution
• Vanguard Environmental
• Nic’s D.U.C.T Works Inc