Greetings! This year we built a 12x28 addition that sits on above ground 6x6 pt posts.. The base footings tho are 48" below the grade. The posts are 14" tall. The walls & ceiling are insulated at R-19. 2x6 construction here in NH. My dilema is the floor. With only 14" of crawl space and a hardwood floor, can I gain some R-value by putting down some plastic sheathing, carpet padding, and carpeting without having to make my thinner(than me) wife crawl underneath to put insulation. The underside is open on 3 sides with excellent ventilation. But that 14" in the real problem. I would really like to solve this problem on the inside of the room if that seems feasible. Thanks and Merry Christmas!

 

Wow! 14 inch crawlspace. What a building code. It must be the same one that was in use when my house was built.

Plastic sheeting on the ground will help control moisture under the addition. It seems that the best approach would be to insulate the underside around the edges then enclose the space with a skirting with insulation. This would avoid having to work in the 14 inch space.

Hope this helps.