Ottawa home owners will soon be allowed to build coach houses in their yards, if new rules presented by city staff are adopted by council later this month.

"The idea of the coach houses is to allow for a gradual and discreet kind of intensification, particularly in lower-density neighbourhoods that might have originally been built as nothing but single, detached houses," said Tim Moerman, the city planner leading the file.

The City of Ottawa has long had zoning to allow for apartments within existing homes, but not for smaller, second units in people's yards.

Now, it's had to come up with such rules, because the provincial government sees coach houses as a way to boost the stock of affordable housing.

After a year of consultation, and input from communities young and old, suburban and urban, staff have released the rules.

Coach House Rules

Moerman believes the city has landed on a "winning formula" for the size of coach house that would be allowed:

In urban areas : one storey and a footprint no greater than 40 per cent the size of the main house, 40 per cent the size of the yard, or 80 square metres, whichever is smallest.

: one storey and a footprint no greater than 40 per cent the size of the main house, 40 per cent the size of the yard, or 80 square metres, whichever is smallest. In rural areas: two storeys (above a garage) and a footprint that is no greater than 40 per cent the size of the main house, 40 per cent the size of the yard, or 95 square metres, whichever is smallest.

two storeys (above a garage) and a footprint that is no greater than 40 per cent the size of the main house, 40 per cent the size of the yard, or 95 square metres, whichever is smallest. Rooftop patios would not be allowed.

There would be other required setbacks from the property line to try to protect neighbours' privacy.

The water and sewer services would have to come from the main house to prohibit the coach houses from being severed from the main property

A home could have an apartment within, or a coach house in the yard, but not both.

"We think that's a formula that works pretty much whatever configuration of house size and lot size you might have," said Moerman. "Whatever coach house you get in there will be quite discreet. It's not going to be a big change to the character of the neighbourhood."

Whether homeowners build a second unit in the yard for an elderly relative, an adult child who has moved back home, or for rental income, is up to them, said Moerman.

Rockcliffe exempt

The former Village of Rockcliffe Park is the one neighbourhood where coach houses would not be permitted.

Bryan Dickson, left, and Peter Lewis, right, of the Rockcliffe Park Residents Association, pushed to have their neighbourhood exempt from any zoning or official plan changes that would allow coach houses and laneway homes. (Hallie Cotnam/CBC) Emotions ran high for Rockcliffe residents who attended a community meeting last spring, said Peter Lewis, president of the Rockcliffe Park Residents' Association.

The issue wasn't about coach houses, per se, but about protecting a district whose heritage status is based on its park-like, low-density character planned in the 1850s, said Lewis.

City staff ended up exempting Rockcliffe because its planning has been treated differently for decades, and has not allowed even apartments within the homes, even though they're allowed everywhere else in the city.

"I do have a concern that the specific heritage aspect of things was not mentioned, but we are happy with the outcome of this report," said Lewis.

Coach house report 'rushed'

But other communities have outstanding concerns, and say time is running out.

Sheila Perry, of the Federation of Citizens' Associations is concerned about what could happen to mature trees on lot lines, and wants more details about basements in coach houses.

"This isn't as thorough as it should be to be able to protect neighbourhoods," she said.

The group reviewed Vancouver's approach to allowing rental units in laneways, and feels Ottawa's version has been "rushed."

Despite wishing more work could be done on Ottawa's coach house zoning, Perry knows there will be no recourse if it receives council approval.

Moerman too has been aware that Ontario will not allow an appeal.

"That's part of why we did the extensive consultation," said Moerman. "When there is no chance of appeal, it's really, really important to get it right."