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Toilet Seat & Bidet Seat Install: Fit, T-Valve, GFCI Outlet

Updated 2026-10-31 · Sources verified 2026-07-20

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Round or elongated: measure from the center of the seat bolts to the front edge of the bowl. Permit in Orange County: no permit needed. Exempt finish work under FBC 105.2 and Orange County's published list — but exempt work must still comply with the Florida Building Code. The full rule and its official source are below, with the code requirements and mistakes that trip up Orlando homeowners.

Key facts before you start

Round or elongated: measure from the center of the seat bolts to the front edge of the bowl. Bemis: 'A round toilet bowl will measure approximately 16-1/2 in in length', an elongated one 18-1/2 in, and the bolt holes are '5-1/2 in' apart (Kohler's spec sheets list 'Seat-Mounting Holes: 5-1/2 in'). Buy by those two numbers, not by the toilet brand.
Getting the old seat off: 'Locate the nuts under the toilet tank and grip them firmly with pliers in one hand' while a screwdriver turns the bolt from above (Bemis); corroded hardware gets 'rust penetrant ... five or ten minutes' first, and 'your tools can easily chip the porcelain of your toilet bowl', so pad them. Plastic nuts that only spin need the bolt held from above; a bolt that is rusted solid is cut flush with a small hacksaw blade worked under the hinge, with tape on the porcelain.
Installing: snap-off hardware is the one that stays tight. Bemis STA-TITE: 'Insert bolts', 'Push bushing onto bolt', 'Place seat on bowl', 'Attach nuts. Finger tighten', then 'As you hold seat centered on bowl, tighten lower section of STA-TITE nuts until they snap off'; the snap 'prevents over-tightening' and the nut 'will NEVER LOOSEN'. Kohler's plastic-nut version: 'tighten the nuts. Do not overtighten', and the quick-release style has you 'Insert the folded anchors through the holes. Verify the anchors unfold after being inserted', 'Position the + toward the seat'. Bemis's reminder on the cover: 'Do Not Stand On Cover.'
Will a bidet seat fit? Bemis's compatibility rule: bolt holes 'less than 5.5 inches or greater than 7.5 inches' apart will not work; 'the distance between the bolt holes and the toilet tank is at least 1.5 inches'; and 'If you have a 1-piece toilet with a deep French curve, our bidets are likely not compatible' (TUSHY says the same about its attachment). Skirted or concealed-trapway toilets hide the seat bolts, so Brondell and Bemis sell top-mount bracket kits; Brondell also flags 'a concealed toilet fill valve' that needs its alternate T-valve. Elongated seats run 20.9 in long (Bio Bidet), round about 19 in.
The water hookup is the same on every seat and attachment. 'Turn off the water shut-off valve. Drain the toilet tank completely by flushing the toilet. Unscrew the hose connected to the toilet tank' (Bio Bidet). 'The T-Valve connects to the fill valve directly under your toilet tank, it does not connect at the wall' and 'Only connect to the cold toilet water supply line' (Brondell; TOTO: 'Connecting to hot water supply may result in burns and equipment damage'). Seat the rubber washer in the T-valve, reconnect the wall hose to its bottom, run the bidet hose to the seat, 'Hand-tighten to secure. Take care not to twist the bidet hose' (Brondell), then 'Open the water shut-off valve slowly and check for leaks', wait five minutes and check again. TUSHY: 'If the hose only turns once before stopping, it may be cross-threading', and leave a towel under the joints for an hour.
Mounting plate first: 'Place the catch plate and bolt guides over the mounting holes. Insert the mounting bolts through the guides, catch plate, and mounting holes', then 'Slide the bidet seat all the way onto the catch plate until you hear a click' (Bio Bidet). A plain attachment sits under your existing seat: 'Reattach the toilet seat on top of the TUSHY by threading the toilet seat bolts through the adjustable flanges' (TUSHY). A rigid chrome supply riser has to go: 'If it is a rigid pipe, you may need to purchase a flexible hose' (Brondell), 3/8 in compression to the 7/8 in tank thread. Use the hoses in the box: TOTO forbids substituting other hoses or valves.
Electric seats need a GFCI outlet within reach, and most Orlando bathrooms have exactly one. TOTO: 'The power cord is 3.9 ft long. Check that the outlet is provided in a location appropriate for this length', 'Always use a grounded (3-prong) electrical outlet ... connected to a ground fault circuit interrupter', and 'Do not install an outlet directly beneath a water supply location.' Bio Bidet (1,400 W): 'It is recommended to operate this product on a separate circuit. Sharing a circuit could cause the breaker to trip or lights to flicker'; TOTO: an extension cord or power strip shared with other devices 'may result in fire from excess heat'. 'Do not plug in the power cord before connecting the water supply hose' (Bio Bidet). No outlet near the toilet means a new circuit or outlet, which is electrical-permit work in Orange County ('Most ... electrical ... work does require a permit'), and the GFCI guide explains why that outlet must be GFCI.
Upkeep: the external bidet filter 'should be changed every six months' (Brondell); run the self-clean cycle on electric seats; wipe hinges where the seat meets the bowl. Hard Orlando water scales nozzles, so a seat that sprays weakly after a year usually needs a nozzle cleaning, not a replacement.
Permit: a seat or bidet seat on the existing fill valve replaces no fixture, valve or pipe, so it sits outside the plumbing work Orange County permits; the one thing that can trigger a permit is the new outlet (see above). Toilets themselves, flanges and fill valves are in the toilet guide.

The permit answer

No permit needed. Exempt finish work under FBC 105.2 and Orange County's published list — but exempt work must still comply with the Florida Building Code.
Source: https://codes.iccsafe.org/s/FLBC2023P1/chapter-1-scope-and-administration/FLBC2023P1-Ch01-SubCh02-Sec105.2

Orange County and the City of Orlando run separate permit offices with separate portals — and your mailing address alone doesn't tell you which one covers your home. Check which permit office covers your address →

Manufacturer instructions

The manufacturers' own instructions this guide is built from. Follow the manual for your exact model; they open on the manufacturer's site.

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Frequently asked questions

Do I need a permit for a toilet seat & bidet seat repair in Orange County, FL?

No permit needed. Exempt finish work under FBC 105.2 and Orange County's published list — but exempt work must still comply with the Florida Building Code.

Are there specific building-code requirements for a toilet seat & bidet seat repair?

Permit: a seat or bidet seat on the existing fill valve replaces no fixture, valve or pipe, so it sits outside the plumbing work Orange County permits; the one thing that can trigger a permit is the new outlet (see above).

What tools or parts do I need to get right for a toilet seat & bidet seat repair?

Getting the old seat off: 'Locate the nuts under the toilet tank and grip them firmly with pliers in one hand' while a screwdriver turns the bolt from above (Bemis); corroded hardware gets 'rust penetrant ...

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Sources

https://toiletseats.com/education-and-inspiration/articles/how-to-measure-a-toilet-seat
https://toiletseats.com/education-and-inspiration/articles/how-to-replace-a-toilet-seat
https://toiletseats.com/assets/Bidet-Toilet-Bowl-Compatibility-1.pdf
https://images.thdstatic.com/catalog/pdfImages/4c/4c4552d0-7bb6-4f20-af56-32780f14a439.pdf
https://www.toiletseats.com/assets/1B5997777-HH111-Platform-Hinge-Installation-wTool.pdf
https://techcomm.kohler.com/techcomm/pdf/1427583-2.pdf
https://techcomm.kohler.com/techcomm/pdf/17676T-0.pdf
https://techcomm.kohler.com/techcomm/pdf/K-4689_spec_US-CA_Kohler_en.pdf
https://www.afsupply.com/pub/media/catalog/product/matridtech/toto/install/SW300401.pdf
https://cdn.shopify.com/s/files/1/2293/0089/files/bb2000_manual_3.7.24.pdf
https://www.brondell.com/content/SE600_owners-manual.pdf
https://attachments.gorgias.help/ldzOw7J9wK2oL59m/hc/XeynJd7OJa29ERow/2026020517-cfcb320b-63d2-4191-87a8-4d2d3036f4bb-classic%203.0%20installation%20manual.pdf
https://engageorange.ocfl.net/fast-track-permitting-services/faqs

This guide is general informational content, not professional or legal advice. Codes and county rules change — confirm permit requirements with your local building department, and use a licensed professional for electrical, gas, structural, or main-line plumbing work.