Building a multiple occupancy?

I know of a property that is literally 100m from a shopping center, trains, and a kilometer from the highway in a growing area which I would think could be perfect for building something to house a number of people. [Provided everything adds up of course]

I was wondering what sort of expenses and returns one could expect from successfully building and tenanting a multiple occupancy?

I’ve read that townhouses/units cost more than normal houses to build, what sort of multiple of the cost could I expect? Twice as much?

Im also interested in people’s thoughts on the idea in the first place.