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.
Framing an addition averages $6 to $8 a square foot nationally. That's the cost of building walls and adding or extending a roof with rafters or trusses. It does not include drywall, doors or windows, insulation, finishing trim or utilities. A 10-by-15-foot bedroom addition, for instance, might cost $900 to $1,200 just for framing.