Just like everyone was once a baby,.... everyone here start off as a noob,...
Of course jackhammering through bedrock would be tougher and expensive than digging through clay,... but biggest challenge is dealing with water.
Toronto is a City of Valleys,.. with rivers, creeks, tributaries,.... both at ground level and underground! A number of previous rivers have been buried,... including Wilket Creek which naturally runs nearby - from Edithvale to Bayview & YorkMills is buried into storm tunnel
https://urbantoronto.ca/forum/threa...-35s-sorbara-wallman-architects.13050/page-10
Map here shows a segment of Wilket Creek Storm Tunnel that's been diverted from Hounslow Ave down Beecroft Ave then across ParkHomes/Empress to Doris
http://www.vanishingpoint.ca/wilket-creek-storm-trunk-sewer
Wilket Creek naturally flow through Ellie Condo site (a block south of here),.... that site is now a bunch of dirt hills as they're likely dealing with underground water issue before construction. Directly across Yonge Street, Majestic Condo (northeast corner of Yonge & Parkview) took a year longer in construction dealing with underground water issues.
South of Sheppard, another underground creek hits the north side of EmeraldPark; and that structure have an underground system that collects the water into an underground water reservoir (10feet wide, 30-40 feet deep) directly in front of their entire Yonge Street frontage stores,.... as long as their filtering system works, the water will then drain into the City storm system - otherwise it gets trucked out to be filtered off-site. Experience flooding issues in underground parking lot due to bad construction.
Directly across Yonge Street, Tridel Hullmark Centre didn't have underground water issue to deal with,... which surprise me, since prior to the old plaza that was there, there used to be a natural marshland/pond there.
At Concord-Adex's Park Place, the land is relatively flat but there's high water level,.... takes longer for underground construction and it's more expensive,.... thus, the underground parking spaces there are about $80K,.... like downtown along harbourfront!
Prior to construction, they test core sample and water level to try to figure out what they're dealing with,....