The point is, hot-dipped galvanized nails will do the job for 99% of the houses out there. I'd only specify stainless roofing nails if I lived at or close to the ocean. Hot-dipped galvanized nails can last well over 100 years in non-oceanic climates.he point is, hot-dipped galvanized nails will do the job for 99% of the houses out there. I'd only specify stainless roofing nails if I lived at or close to the ocean. Hot-dipped galvanized nails can last well over 100 years in non-oceanic climates.
Costs more to build out. As you said, there are all kinds of other factors, but the same square footage in two stories will cost less to build than in one. Most homes with traditional foundations can sustain a second floor addition without additional support.
In the US, the average cost to build a come is $100 a square foot. This figure goes up and down depending on the specific location of the home. Building a home with high quality cabinets, flooring, countertops, etc. can add to the construction cost. I do not recommend using an estimate of more than $130 a square foot.