Adding a Spa to an Existing Pool in Royse City, Texas

When a spa counts as a swimming pool

Royse City's pool ordinance defines a swimming pool as any pool, hot tub or spa, above or below ground, that holds or can hold water 1½ feet deep or more. A spa built onto a pool therefore falls under the same division of the code as the pool itself. The City requires a building permit for every swimming pool, and the plans for the pool and its enclosure have to show they comply before that permit is issued.

The City's Swimming Pool, Spa & Hot Tub Permit Information Guide lists a residential in-ground pool permit at $400, an above-ground pool at $125 and a residential spa or hot tub at $150, and states that no work may begin until the permit has been issued. It doesn't say which line applies when a spa joins a pool that is already there, so the Building Inspection Department sets how that job is permitted; the City's permits page also carries a separate guide for residential remodels and additions.

Royse City adopted the 2018 International Swimming Pool and Spa Code by Ordinance 22-09-1538 on September 13, 2022, and the pool guide lists it beside the residential, building, plumbing and fuel gas codes and the 2023 National Electrical Code. Every sub-contractor on a pool job has to be registered with the City and named on the permit application.

The 6-foot enclosure and glass near the water

The ordinance asks for a fence, wall or other structure at least 6 feet high around the pool, with no opening other than a door or gate wider than 4 inches, no more than 3 inches of space under the bottom, nothing that makes it easy to climb, and self-closing, self-latching gates latched in the upper quarter. While work is under way, the guide calls for erosion protection and a 4-foot temporary fence that stays up until the permanent fence is in.

At the belly-steel inspection the City checks the pool's setbacks, the permanent barrier and the windows: glass whose bottom edge is less than 60 inches above the walking surface and within 60 inches of the water's edge must be tempered. A spa set closer to the house than the pool can bring windows inside that zone.

Drainage, septic reviews and drought stages

In Royse City a pool may be drained, partly or completely, only through a connection to the City's sanitary sewer. An owner without a sewer connection arranges the drainage through the building official at their own cost, backwash of no more than 50 gallons is exempt, and new pools have to be built to drain to the sanitary sewer; the pool guide adds a P-trap of at least 3 inches for filter backwash, joined by an air gap. For properties on a septic system, the permits page lists an OSSF (on-site sewage facility) pool permit review.

The City's drought plan, codified through June 23, 2026, names spas as well as pools. In Stage 2 a newly built swimming pool, Jacuzzi or spa may be filled once, and a drained private pool, Jacuzzi or spa may not be refilled without the public works director's authorization. In Stage 3 existing pools and spas may only be topped up to operating level, with no draining or refilling. If a spa addition means lowering or draining the pool, the stage in force decides when the work can start.

The City buys its water from the North Texas Municipal Water District, but the Texas Water Development Board's map puts only about 42.5% of Royse City's Census area in the City's own water service area. B H P WSC and Nevada SUD cover about 8.0% each, Cash SUD and Blackland WSC smaller pieces, and about 40% falls in no mapped service area (calculated), so check which utility serves the address before relying on the City's stages.

Newer homes and the clay beneath them

The 2020 Census counted 4,607 homes in Royse City, 1,342 more than in 2010. In the Census Bureau's 2020–2024 survey, 48.9% of the city's 7,146 homes were built in 2010 or later, 1,683 of them since 2020, and 29.4% from 2000 to 2009; the median year built is 2010. Single-family detached houses make up 85.5% and mobile homes 7.2%, about 83.8% of occupied homes are lived in by their owners, and the median value of an owner-occupied home is $322,500. The Census doesn't count pools or spas, so these figures show how new the houses are, not how many backyards already have a spa.

On the USDA Natural Resources Conservation Service soil map, Houston Black clay units cover 32.0% of the city, Burleson clay 15.4% on 1 to 3 percent slopes and 4.6% on flatter ground, and Leson clay 12.6%, with Tinn clay on frequently flooded land at 6.8%. NRCS gives the main Houston Black soil a linear extensibility, its measure of shrink and swell, of up to 12 percent with up to 55 percent clay. The units it rates very limited for slab houses, with shrink-swell among the reasons, cover 59.1% of Royse City's mapped land; those ratings are written for houses, not pools or spas.

How a spa is added to an existing pool

1. 01

   Plans and the permit

   The site plan shows the spa, the pool and the enclosure meeting the City's pool rules, every sub-contractor is registered and listed, and no work starts until the permit is issued.

2. 02

   Dig and set the steel

   The spa is dug beside the pool and its steel set, and the City's belly-steel inspection looks at the setbacks and the permanent barrier.

3. 03

   Plumbing under test

   New spa lines are tied in and pressure-tested; the City's guide wants the piping to hold a 25 psi water or air test.

4. 04

   Deck steel and expansion material

   Around the spa, the deck steel goes in as #3 rebar on 18-inch centres with expansion material, ready for the deck-steel inspection.

5. 05

   Finish, fill and first heat

   Under Stage 2 a new spa may be filled once. Pebble Technology International asks for no heater in the first 14 days, and NPT says not to let a spa flow into the pool during the fill.