Most apartment style condo buildings have at least one level of underground parking in Ottawa while typically town house or up/down split style condos, have outdoor surface parking spots. The number of spots each developer must build will mostly depend on the zoning. Most spots are a standard width, and can fit a standard car (but not all buildings are the same - more on this later).
The parking garage typically has access to the main elevators (older buildings might have a separate elevator), along with some of the storage locker rooms and bicycle rooms or area. They typically are heated and ventilated.
When looking at pre-construction the price of a parking spot will first depend on the type of condominium (townhouse or highrise). For example - Valecraft Homes is including one outdoor parking spot for free with the unit purchase at Woodroffe Lofts and a second spot can be purchased for $10,000. Compared to Claridge who is offering an underground parking spot at an additional cost of $35,000 per space at Claridge Icon.
Next, the cost might rise depending on location within the parking garage. Some builders will offer the premium spaces on level 1 for $5-15,000 more per space - on top of the $35,000. Not every builder does this, some save the premium spots for the large or penthouse units.
Keep in mind, there is also a monthly cost in addition to the purchase price. Since your percentage of ownership goes up in the building, your condo fees will rise as well. Some pre-construction buildings will project an additional $35-45 per month, while parking spots in some re-sale buildings can add $60-90 per month to your condo fee.
While no developer will share the true cost to build a spot, we have always been told it was more than they typically charged, up to almost double to cost - depending on how many levels below ground they need to go. Obviously outdoor surface spots will be a fraction of the cost, since there is less involved in the construction. Zoning requires a certain amount of spots be built per unit. It can range from 0.5 to 0.7 parking spots per unit - or more further outside the downtown core.
Keep in mind that not every unit is able to purchase parking when buying pre-construction. Since the builder will build as few spots as possible, they will restrict which units can or can not purchase a spot. Typically this restriction falls on the smallest units. Assuming that the smaller unit is less likely to have a vehicle, compared to the large units with multiple residents who might require two etc. Most builders will have a list for when larger units opt out of the spot, to allow the smaller unit owners the chance to purchase. However, when the building is handed over to the owners, you are then able to purchase a spot from another owner.