It is happening all around the neighbourhood. I know it is feasible.

Worthy?

It is worthy for Toronto, yes.

@worthy needs the @ symbol.

Suggest you ask your neighbours who have done this. You just reaffirmed a family member’s decision to leave TO.

Many parts of the city have single-family detached homes on 20'-25' lots.

Here's one two doors over from an infill build I bought and flipped the next year.

Before: s. C$1,001,000, 2015 166 Bedford Park Avenue, North Toronto.

After: sold March 2021 C$2,626,000 (US$2,279,000)

Lot 20'x125'

First, check zoning. There is a lot of old spot zoning in downtown areas. So you need to provide the actual street address. Counters are still closed. But you can call as per below:

As for demolishing half a semi-attached home, I wouldn't count on getting a demolition permit without a structural engineer's plan as to how to keep the remaining half upright and habitable. Typically, Toronto semis were built with a double brick wall between the two halves. They are not two self-supporting structures mated together. 19th Century frame ones were often ramshackle, built from scrap. (South of Harbord.)

54 1/2 St. Patrick St. 2020

If any zoning variances are needed though, expect to face opposition.

@worthy - Thank You. I am not far from Bedford. Would you know a builder that could quote me on what I intend to do?

Your design professional can help you with references to active builders. Also, take note of the builder and architect signs on active projects you like in the area. Houzz Find Professionals is a good start too. It's up to you to do the weeding!

Do you own both sides of the house? Interesting idea. How wide is each side of the lot? Do you have required side setbacks?

Millions of dollar. Literally a multi million dollar budget, well above building on an open lot that doesn’t have the added expenses of starting with an albatross.

Figure at least C$300 sf for a high-end build.

Considering the neighbourhood, a better use of the land might be to demolish both semis and build two detached homes. (Or just sell the lots in this boom market and pocket the profit without the headaches of building.)

If you only own one of the existing semis, the other owner might be willing to partner with you.

I had a friend who sold his detached home, as did his neighbour, to a builder who then sub-divided the two lots into three.

Did you end up building a home on a semi lot? How did it go? Any learnings? I am thinking of the possibility of doing one on a lot that is 25' wide in little Portugal.