NYC Renovation Case Study
Bathroom Addition in Long Island (2022)
A 2022 Long Island project adding a full new bathroom into unused space, with new plumbing, electrical, waterproofing, tile, and fixtures.
Get Your Free On-Site EstimateThis 2022 Long Island project added an entirely new bathroom into previously unused space in a single-family home, including new plumbing lines, an added electrical circuit, ventilation, waterproofing, tile, fixtures, and finish carpentry. For a comparable bathroom addition today, homeowners should generally plan for about $35,000–$65,000 and 6–10 weeks of construction, depending on how far plumbing and electrical lines must travel and the finish level selected.
The Project
Adding a New Bathroom to a Long Island Home
The archived project media documents a full bathroom addition built into previously unused space in a Long Island single-family home. Because the room didn’t previously have plumbing or a dedicated electrical circuit, the scope started below the finish surfaces — running new supply and drain lines, adding a vent stack tie-in, and wiring a new circuit before any waterproofing or tile could begin.
The finished bathroom pairs a tiled tub-shower with a vanity and fixtures selected to match the rest of the home, giving the household a second full bathroom without altering the home’s existing floor plan.
Completed Work
Before, During & After the Bathroom Addition
Illustrative completed-work views based on archived project media, showing the space before the addition and the finished bathroom.
What Was Involved
Building a Bathroom Where None Existed
- New plumbing linesSupply and drain lines were run to the new location, with a vent stack tie-in confirmed against local code before walls closed.
- Dedicated electrical circuitA new circuit was added for lighting, a ventilation fan, and GFCI-protected outlets required in a bathroom.
- Waterproofing and tileBacker board, waterproofing membrane, and tile were installed around the tub-shower and floor before fixtures went in.
- VentilationAn exhaust fan was added and vented to the exterior to control moisture in the new space.
- Fixtures and finish carpentryVanity, toilet, tub-shower fixtures, and trim were installed and matched to the home’s existing finish palette.
Cost & Timeline
Current Planning Ranges for a Long Island Bathroom Addition
| Comparable scope | Current planning range | Construction time |
|---|---|---|
| Bathroom addition with short plumbing run | $35,000–$50,000 | About 6–8 weeks |
| Bathroom addition with longer plumbing/electrical runs | $50,000–$65,000+ | About 8–10 weeks |
These are current planning ranges, not the private invoice for this 2022 project. Distance from existing plumbing and electrical, permit requirements, and finish selections can change both cost and schedule.
Five Steps
How a Bathroom Addition Moves Forward
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Assess plumbing and electrical accessConfirm how far new lines and a vent stack tie-in need to travel from the nearest existing service.
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Finalize layout and fixturesConfirm the tub-shower or shower layout, vanity, and fixture selections before ordering materials.
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Secure permitsFile for the Department of Buildings and plumbing/electrical permits required to add a new bathroom.
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Build in trade sequenceRough-in plumbing and electrical, pass inspections, then move through waterproofing, tile, and fixture installation.
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Test and close outCheck water pressure, drainage, ventilation, and electrical, then complete the final punch list.
For Homeowners
What to Confirm Before You Start
Adding a bathroom where none existed depends heavily on how far new plumbing and electrical lines need to travel. Before work begins, have your contractor confirm the nearest usable supply, drain, and vent stack connections, since that distance drives both cost and how much of the surrounding floor or ceiling needs to be opened.
Explore our bathroom renovation process, browse more NYC and Long Island renovation case studies, see where we work, or request an on-site estimate.
Frequently Asked Questions
Long Island Bathroom Addition FAQs
How much does it cost to add a new bathroom in a Long Island home?
Comparable bathroom additions currently plan around $35,000–$65,000, depending mainly on how far new plumbing and electrical lines must travel from existing service and the finish level selected.
How long does adding a new bathroom take?
Construction commonly takes about 6–10 weeks, depending on the length of plumbing and electrical runs and how much of the surrounding floor or ceiling needs to be opened.
Do I need a permit to add a new bathroom?
Yes. Adding a bathroom requires Department of Buildings permits along with plumbing and electrical permits, since new supply, drain, vent, and circuit work is involved.
Can a bathroom be added without existing plumbing nearby?
Yes, though cost and schedule increase with distance from existing plumbing. Your contractor should confirm the nearest usable supply, drain, and vent stack connections before finalizing the layout.
Plan With Clear Numbers