Underwriting New Const Duplexes or units less than 5yrs old

What figures would you use in figuring Repairs or Capital Expenditures when either underwriting a new construction duplex/group of duplexes or possibly purchasing a group of newer (around 5 or so years old) duplexes.

All would be class A at least for my local area - Granite counters, sprinkler systems, 2 or 3 car garages, 3 bdrm 3 bath, Smart Siding (50 yr siding) etc.

I'm sure the same logic could apply to a new construction or newer build apartment complex.