Reed Construction Data caters to architects, builders, construction etc. The periodical they used to sell was a daily newspaper. The perceived benefit is they would list opportunities to BID on projects not yet decided - so you are getting in at the ground floor although in your case, maybe you would rather connect when the contract is done so you know who it is you can contact for job.
It could be expensive - but they may also have a web option which is a pay-as-you go solution and since your market is the GTA - you would pay for a region (vs the entire country of Canada) and then you access from home (easier for you than getting a paper delivered and targeted to your market region)
I did cold calling in another life, its brutal, and I found it only works if you have a packaged product or concept that you can quickly communicate into choice 1 or choice 2 (you never want to give them the choice to say no). While I have never tried to sell photography door to door - I have done sales, and find you can find people who will chat with you (because they are bored) - but that may never buy anything. Its therefore important (as I am sure you know) to track your calls, and your closing ratio - because otherwise its a make busy project which over time looses more money than just staying at home.
Also, I do contract work in corporations (my paying job at present that allows me to develop my photography) and things like security have really prevented anyone from getting past the pitt bull at the front door assuming they even have a receptionist (many have silicone sally IVR and just a buzzer that allows people entry to a certain point )
Your comment about vendor trade shows and booth costs is valid and my instinct is its too expensive for a small business which you seem to be - but since I don't know your market I am just giving an opinion. I did trade show booths (some years ago and it was not photography but consumer packaged goods) and the rule we used to have was the gross revenue earned should equal 10x what you paid for the booth - for what its worth.