Cost to build a 6 floor 12 units apartment building

[Yunning Lee]

Hi Everyone:

I am new to this forum. This is literally the first discussion I posted here. We are currently under an agreement of a 4-plex of 1million. We are debating whether it is a good idea to buy this property or find a better opportunity.

We can build 6 floor 12 units (2bed, 1 bath, 800-1000sqft per unit) on this lot. What would be the approximate cost to build such an apartment building.

Also, if we decide to go this path, how to estimate the market value of apartment building? I never bought any apartment building before. Is the estimation of apartment building similar to residential house? Residential property usually uses comparison of similar house recently sold in that area. But apartment building is quite difficult to find such comparables. If it costs 3 millions to build and the value of this building is only 4million, then it doesn't make sense to me.

Can anyone give me some opinion or suggestions?

Many thanks!