Minimum size for new apartment development?

[Ryan K.]

What is the minimum building size and/or lot size for a new apartment building?

I am analyzing a potential deal now.  It is an old farm house and various outbuildings on 1.4 acres, but it's riverfront views and in-town location is zoned for high-density multi-family residential.  Colorado and western investors will also perk up to this: it includes senior water rights.  Our town has a history of acquiring water rights in exchange for project approvals, so I see it as a significant bargaining chip.  The list price reflects an old house on the biggest piece of land in-town, not a future development parcel.

As a commercial appraiser, I do not have development experience.  But my job is essentially a daily study in how to make money on real estate, and this opportunity greatly intrigues me.  Please offer advice or point me toward resources to help with this decision, specifically, what is the minimum apartment size or land size for new construction apartments/townhomes?