Can I switch from rectangular to round downspouts on my heritage Ottawa home?

Switching from rectangular to round downspouts on a heritage Ottawa home is absolutely possible from a technical standpoint, but there are important heritage planning considerations that could determine whether you need approval before making the change — and in some cases, whether the change is permitted at all.

Heritage Designation Matters First

The most important question to answer before touching anything on your home is whether your property is individually designated under the Ontario Heritage Act, or whether it sits within one of Ottawa's heritage conservation districts. Ottawa has several protected heritage areas — Centretown, Sandy Hill, Lowertown West, New Edinburgh, Rockcliffe Park, and Woodroffe North among them. If your home falls into any of these categories, replacing or altering exterior features like downspouts may require a heritage permit under Section 42 of the Ontario Heritage Act. This is not a building permit — it's a separate approval through Ottawa's Heritage Planning staff. The simplest way to find out is to call 3-1-1 and ask whether your property is designated or within a heritage conservation district. Do this before ordering materials or hiring anyone.

If your home is simply older in style but not formally designated, you have much more flexibility and no heritage permit is required for downspout changes.

From a purely functional perspective, round downspouts and rectangular downspouts move water at similar volumes when properly sized. The standard 2-inch by 3-inch rectangular downspout handles roughly the same flow as a 3-inch round downspout, and a 3-inch by 4-inch rectangular is comparable to a 4-inch round. On a heritage home with a steep roof or large drainage area — common in older Ottawa neighbourhoods — make sure any round downspout you choose is sized to handle Ottawa's intense summer thunderstorms, which can dump 30 to 50 millimetres of rain in under an hour.

Aesthetically, round downspouts have a traditional look that suits many period-style homes, particularly those with half-round eavestroughs, which are common on heritage properties. The combination of half-round gutters and round downspouts was the standard before K-style profiles became dominant in the mid-20th century, so switching to round may actually be more historically appropriate depending on your home's era. If your home currently has half-round eavestroughs, round downspouts are the natural match and connect with standard round outlet fittings.

On the cost side, expect to pay $200 to $600 per downspout for professional installation in Ottawa, including removal of the old rectangular unit and connection at grade. If your home is copper — common on heritage properties in Rockcliffe Park and New Edinburgh — copper round downspouts are available but will run toward the higher end of that range, and joints should be soldered rather than sealed for a permanent watertight connection.

Timing-wise, the optimal window for this work in Ottawa is May through October. Avoid late fall installations when temperatures drop quickly, as sealants and some connection fittings don't cure properly below 5 degrees Celsius. Fall is also the busiest season for eavestrough contractors, so booking early gives you better scheduling options and sometimes better pricing.

One practical tip: when you have the downspouts replaced, confirm that the discharge point is directing water at least 1.8 metres from your foundation. Ottawa's clay-heavy soil drains poorly, and water pooling near the foundation is a leading cause of basement moisture issues in older homes.

If you're ready to get quotes or want to explore contractors experienced with heritage properties, the Ottawa Construction Network directory at justynrookcontracting.com is a free resource where you can browse eavestrough professionals in the Ottawa area. Getting at least three written quotes is always worth the effort on a project like this.