How much does it cost to insulate a single room?
Insulation works by preventing the transfer of air from areas of warmth to cool. This works both to keep conditioned air indoors during hotter weather and also prevents heated air from escaping during colder months too.
When a room seems to be uncomfortable regardless of the use of air conditioning or heating it is usually due to the inefficiency of the insulation in the walls and ceilings. For the purpose of this discussion we will look at the costs and requirements associated with the insulation of a 20'x12' (or a 240 square feet) room.
This is a project that can be either a DIY or a professionally contracted one, and cost variations will be quite significant due to the hourly charges for labor.
Generally, the typical room insulation costs will include:
- The Ceiling or Attic - the costs for insulating the attic area to "modern standards" are from $1 to $1.50 per square foot. This assumes that it is a DIY project and uses R49 value insulation. Should the homeowner require the services of an insulation contractor who uses blown cellulose materials, the costs will double to roughly $3 per square foot instead. This means that the 240 square feet of ceiling/attic will cost between $360 and $720 to complete;
- The Walls - wall insulation will require an R15 to R18 value, and this depends upon the presence of exterior sheathing beneath the siding of the home. This usually has a minimum R-value of 5, and this will determine the level that the new insulation will be. The insulation is going to run between $.73 and $.95 per square foot. This means that 504 square feet of wall space is going to cost between $368 and $470 for materials alone. If it is the blown varieties the costs will again double and will have to include labor as well; and
- The Floor - if a home is built above a crawl space there will be the need to consider improving or upgrading the insulation beneath the floors. This is usually an R19 value that costs around $.95 per square foot to purchase. The 240 square feet of flooring in this room would translate to $230 in materials, plus any additional labor. Carpenters average around $40 to $50 per hour, and they are a good choice when opting to pay someone to properly install new insulation within floors walls and ceilings.
Additional considerations and costs
- Energy audits - before insulating a single room it is a wise idea to contact the local utility company and request a home energy audit. This is done free of charge by most providers and it will point out areas of weakness where insulation is concerned; and
- Rebates - during any insulation project it is advisable to find out about any financial incentives or rebates given out to those doing such work. For example, while a pair of carpenters is insulating the walls it might be the ideal time to replace an old or inefficient window in that wall as well. Both the insulation and the window will qualify for rebates and incentives on the federal and state levels.