Bathroom Remodeling in Smithtown, NY

Smithtown takes residential permit applications online, which is the least painful filing process in Suffolk. Call (631) 360-7522 for a current fee rather than trusting a published figure, because the Town's own FAQ says the posted numbers are dated.

What we see in Smithtown bathrooms

Smithtown takes residential permit applications online, which on a bathroom is a genuine convenience because bathrooms are filed more often than any other room in a remodel.

The Smithtown houses we work in often have a main bathroom that is dated rather than failing, where the layout is sound and the fixtures have simply had their twenty years. That is the cheapest kind of bathroom to do well, because nothing has to move.

What needs a permit in Smithtown

Vanity swap, retiling, new fixtures in the same places — finish work, generally no permit. Toilet or shower drain moves, tub converts to a walk-in shower, a bathroom gets added, or a bathroom goes in a basement — permitted work, every time.

The Suffolk catch: adding a bathroom to a house on septic rather than sewer can trigger a Suffolk County Health Services review, because the system was sized for a set number of fixtures. It runs separately from the town permit, on its own timeline. Redoing an existing bathroom does not raise it. Filing detail for Town of Smithtown Building Department.

Four things decide whether a bathroom lasts, and none of them are the tile: the subfloor, the venting on a moved toilet, the waterproofing membrane behind the tile, and where the exhaust fan actually terminates. What to ask about each. We measure on site for free and put the number in writing as a scope with a total.

Verified August 2026. Requirements and fees change and each department publishes independently. Confirm anything here with the Town of Smithtown Building Department at (631) 360-7522 before you order materials or sign a contract.

Also serving, near Smithtown

We are based in East Patchogue and work across Suffolk County. If you are inside an incorporated village, the village building department governs rather than the town.

• Patchogue
• Medford
• Islip
• Bay Shore
• Huntington

If your town is not on the list, call anyway — the list is where we work most, not a boundary. Anything from Nassau through the Twin Forks is fair game; we tell you honestly if travel makes a small job uneconomical.

Frequently Asked Questions

Can I apply for a Smithtown bathroom permit online?
Yes. Smithtown takes residential building permit applications through an online portal, which is useful on a bathroom because bathrooms are filed more often than most rooms. Call the Building Department at (631) 360-7522 for a current fee, because the Town's own FAQ notes the published figures are dated.

Do I need a permit for a bathroom remodel in Smithtown?
Replacing a vanity, retiling or swapping fixtures in the same locations is generally finish work and needs no building permit. Moving the toilet or shower drain, converting a tub to a walk-in shower, or adding a bathroom is permitted work. There is far more plumbing in a bathroom than a kitchen, so that line gets crossed more often.

Does adding a bathroom in Suffolk County need Health Department approval?
It can. If the house is on a septic system rather than sewer, adding a bathroom may trigger review by Suffolk County Department of Health Services, because the system was sized for a set number of bedrooms and fixtures. That review is separate from the town building permit. Redoing an existing bathroom does not raise it.

Is tile waterproof?
No. Tile is not waterproof; the membrane behind it is. Ask specifically what waterproofing goes in behind the tile, because it is the part you never see and the only part that decides whether the wall lasts.

Related Reading

• Bathroom permits by town — the full breakdown
• Bathroom remodel cost — 2026 Long Island numbers
• Walk-in showers — the conversion that needs a permit
• Septic and Suffolk projects — when SCDHS gets involved
• Bathroom remodeling in Suffolk — local considerations