Cost to Convert a Half Bath to a Full Bath
Converting a half bath to a full bath adds a shower or tub and may require expanding the room by removing walls or taking space from an adjacent area. The work involves new framing, plumbing supply and drain lines, electrical wiring for lighting and ventilation, and careful waterproofing around fixtures. It is a hard project because structural walls may be involved.
- Conversion materials (framing, insulation, drywall, finishes)1.1 each @ $8,000$8,800
- Supplies subtotal$6,050–$15,400
- Labor$6,000–$14,400
- Permits & fees$950
Based on 1 bathroom (typical size). Figures are ballparks — get a contractor quote to confirm.
Common reasons homeowners do this job
- The existing half bath falls short of the household's needs.
- A shower or tub is wanted where there is currently only a sink and toilet.
- A bathroom upgrade is part of a larger remodel.
- Space from an adjacent room is available for a larger bathroom.
- Existing fixtures are being replaced as part of a full bathroom update.
DIY or call a pro?
A licensed professional should handle this conversion because it involves structural work as well as significant plumbing and electrical changes. Structural walls may be load-bearing, so consult a professional before demolition. Incorrect plumbing can cause leaks and water damage, while incorrect electrical work creates a fire hazard. Check with your local building department whether this work needs a permit.
Frequently asked questions
- Can I convert a half bath to a full bath myself?
- Hire a licensed professional to perform the structural, plumbing, and electrical work. Professional input is especially important before removing any wall, since it may be load-bearing.
- What makes a half-bath-to-full-bath conversion more expensive?
- The price can rise with the size of the bathroom, labor time, and the materials selected, including the shower pan or bathtub kit, fixtures, greenboard drywall, lumber, and electrical supplies. Removing old materials can add haul-away or disposal work, and a small scope can still involve a minimum or trip charge.
- What should be checked before choosing a shower pan or bathtub?
- First assess whether the floor plan can fit the new fixture or needs walls removed or space borrowed from an adjacent room. Have a plumber verify that the existing drain and supply lines can support a shower or tub, and have an electrician confirm capacity for new lighting and ventilation.
- How are the new bathroom walls and fixtures protected from moisture?
- The wall finish includes moisture-resistant greenboard, and waterproof caulking is applied around every fixture and seam. Caulking is essential, since improper plumbing can lead to leaks and water damage.
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