Glue down is more for us. The glue often costs .75/ft. If the subfloor is concrete, sealer (2 coats) adds another .50/ft. Then you add $3/ft. minimum for the install itself. Nail downs start at $3/ft. Wood floors are all we do and we are very conscious of doing our jobs to the best of our ability.
1 Home addition cost estimates of $80 to $130 per square foot for a basic family room addition is common. 2  If the home addition includes a bathroom and/or a kitchen, the room addition costs can easily escalate to $200-250 per square foot.
1 Adding new floor space for a simple bedroom and closet with a foundation (but no bathroom) costs about $25-$50 a square foot if you do all or most of the work yourself (requires high-level skills), and anywhere from $50-$150 or more a square foot to hire a builder, depending on complexity and local labor rates. If you're adding weight to your foundation, you may need a report from a structural engineer at a cost of $300-$800 or more, to see if your existing foundation needs to be reinforced or repaired. 2  You'll probably need a set of plans for your bedroom addition. 3  Your builder might be able to supply them.