Garage Drywall Conversion in Greenville: Code, Insulation, and Cost

What 5/8" Type X drywall is

Garage conversions are popular in Greenville — turning an underused two-car garage into a home gym, office, or extra bedroom can add livable square footage at a fraction of the cost of an addition. The drywall portion is straightforward, but only if you know the code requirements for garage-to-house separation and the assembly upgrades needed to make the space comfortable year-round.

Garage-to-house separation requirements

Start with the basics: South Carolina building code requires 5/8" Type X drywall on the garage side of any wall separating the garage from the house. Type X is a fire-rated gypsum board that provides a one-hour fire resistance rating, which is the minimum for garage separations. The drywall must be screwed (not nailed) at 12" centers, and all penetrations (electrical, HVAC) must be sealed with fire-rated caulk or putty pads. Inspectors check this carefully.

Adding insulation behind drywall

If you're keeping the space as a garage but finishing it for cleaner appearance and minor temperature control, hanging 5/8" Type X on all walls and ceilings is a solid project. Most Greenville two-car garages run about $1,800–$2,800 for hang and finish, Level 3 or Level 4. We commonly upgrade exterior walls to insulated with R-15 fiberglass before drywall, which adds about $800–$1,400 in material and labor.

Finished garage as living space

If you're converting the garage to fully heated and cooled living space, the assembly gets more involved. Exterior walls need full insulation (R-15 or R-19 batts plus a continuous insulated sheathing if you're being thorough), the garage door opening needs to be framed in with a wall and window, the slab may need insulation and a moisture barrier, and HVAC needs to extend service to the new room. We coordinate with HVAC and electrical subs to schedule drywall after all rough-ins are complete.

Typical project cost

Code consideration for converted garages: the new living space must meet residential ceiling height (7'6" minimum in most areas), egress window requirements if it'll be used as a bedroom, and proper ventilation. Greenville building permits typically catch these requirements during plan review, but we've also seen DIY garage conversions where these were missed and had to be retrofitted.

Cost: a full garage-to-living-space conversion in Greenville, including framing, insulation, drywall, HVAC extension, electrical upgrades, and finishes, typically runs $20,000–$40,000 depending on size and finish level. The drywall and insulation portion alone is usually $3,500–$6,500. Compared to a new addition (typically $200–$350 per square foot in our area), garage conversions are a great value.

Call Drywall Greenville at (864) 555-0100 to discuss your garage project. We work with several local GCs who specialize in conversions, or we'll handle the drywall scope directly if you're managing the project yourself.