Research by Ivan Tchesnokov
City of Allen Building & Permitting Division
Allen City Hall (1st Floor), 305 Century Parkway, Allen, TX 75013
Phone: (214) 509-4130 · Email: bpplanreview@allentx.gov
CSS Portal: cityofallen.org/permits →
Allen TX Post-Tension Slabs — ALL Drain Relocations Require Concrete Cutting + GPR Scan
Allen homes are almost universally built on post-tension slabs. Moving any drain requires concrete saw-cutting ($1,500–$4,000). GPR scan mandatory before cutting to locate PT cables ($400–$800). Never cut without GPR assessment. Contact (214) 509-4130.
HOA Approval Required Separately From City Permit
Allen has very high HOA penetration. Exterior projects often require HOA architectural review board approval in addition to the city permit. Check your CC&Rs before starting. City does not enforce HOA rules.
The Short Answer
It depends on scope — most bathroom renovations involving plumbing or electrical changes require permits.
Apply electronically through CSS at cityofallen.org. Phone: (214) 509-4130. 2021 IRC governs. Texas TDLR-licensed plumbers and electricians required. Oncor TDU for electricity; Atmos Energy for gas. Post-tension slabs: GPR scan mandatory before any drain relocation. Cosmetic-only work is permit-exempt.

Allen TX bathroom permit rules — the post-tension slab reality

Bathroom renovation permits in Allen go through the CSS (Citizen Self-Service) portal at cityofallen.org. All permits are submitted electronically. Phone: (214) 509-4130. Email: bpplanreview@allentx.gov. The 2021 IRC (effective July 1, 2022) governs. Texas TDLR-licensed plumbers (TSBPE) and electricians hold trade permits. Homeowners must complete a Homeowner's Affidavit for DIY work.

Oncor Electric Delivery (TDU) provides electricity distribution; Atmos Energy provides natural gas. Service changes for either require utility coordination alongside the city permit. Cosmetic bathroom work is permit-exempt: same-location fixture replacement, retiling, repainting.

The post-tension slab is the dominant factor in Allen bathroom renovation costs. North Texas's expansive black cotton clay makes basement and crawl-space construction impractical. Allen's housing stock — primarily post-1985 construction — is almost universally built on post-tension slabs. Moving any bathroom drain requires: (1) a GPR (ground-penetrating radar) scan to map post-tension cable locations ($400–$800), then (2) concrete saw-cutting between the cables ($1,500–$4,000 for plumbing + concrete). Never allow slab cutting without a GPR assessment — cutting a PT cable causes immediate, serious structural damage to the slab.

Know your Allen TX permit requirements before starting.
Your scope, HOA status, and Allen address. CSS portal, post-tension slab check, and contractor registration.
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Scenario A
Tub-to-shower conversion in an Allen TX post-tension slab home
Texas TSBPE-licensed plumber applies for plumbing permit through CSS portal. GPR specialist scans slab to map PT cable locations before cutting ($400–$800). Saw-cuts slab between cables at tub drain, reroutes PVC drain to shower pan position, patches concrete. Rough plumbing inspection before patch sets. Texas TDLR-licensed electrician submits electrical permit through CSS for GFCI upgrades. Total: $11,000–$23,000 (PT slab scope included). Contact (214) 509-4130 for permit fee.

Every project is different.

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Bathroom taskPermit required in Allen TX?
Same-location replacement, retile, repaintNo permit. Cosmetic at existing connection locations is permit-exempt.
Move drain (post-tension slab)Plumbing permit through CSS. Texas TSBPE-licensed plumber. GPR scan first ($400–$800). Concrete saw-cutting. ~$1,500–$4,000 for plumbing + concrete.
New GFCI circuitsElectrical permit through CSS. Texas TDLR-licensed electrician. 2023 NEC (Texas statewide): GFCI on all bathroom circuits.
Gas line modificationsPlumbing/gas permit through CSS. Texas TSBPE-licensed plumber. Atmos Energy gas. Pressure test before concealment.
Structural wall removalBuilding permit through CSS. City-registered contractor. 2021 IRC structural documentation.
Allen's post-tension slabs, Oncor ERCOT, and HOA requirements define every project here.
Your scope, HOA status, and Allen address. CSS portal and Texas contractor licensing.
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What bathroom remodels cost in Allen

Cosmetic refresh (same locations): $9,000–$20,000. Tub-to-shower (PT slab, GPR + cutting): $11,000–$23,000. PT slab GPR scan: $400–$800. Full gut renovation: $20,000–$45,000. Contact (214) 509-4130 for permit fee.

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Your scope, HOA status, and address. Fee estimate and inspection sequence.
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Common questions about Allen TX bathroom remodel permits

How do I apply for a bathroom permit in Allen TX?

All permits submitted electronically through Citizen Self-Service (CSS) at cityofallen.org. Phone: (214) 509-4130. Email: bpplanreview@allentx.gov. Texas TDLR/TSBPE-licensed contractors for trade permits. Homeowner's Affidavit for DIY projects.

Why are post-tension slabs so common in Allen?

North Texas's expansive black cotton clay soil makes basement construction impractical and creates significant ground movement as moisture content changes. Post-tension slabs resist the clay's swelling and shrinking better than conventional slabs. Allen's rapid post-1985 growth coincided with widespread DFW adoption of PT slab construction, so most Allen homes have PT slabs.

How much does it cost to move a bathroom drain in an Allen PT slab home?

Moving a bathroom drain in Allen requires: (1) a GPR scan to locate PT cables before cutting ($400–$800), then (2) saw-cutting the concrete, rerouting the PVC drain, and patching the concrete ($1,500–$4,000 for combined plumbing and concrete work). Total: approximately $1,900–$4,800. Never allow slab cutting in Allen without a GPR assessment.

Who provides electricity and gas to Allen TX?

Oncor Electric Delivery (TDU) provides electricity distribution infrastructure in Allen. Atmos Energy provides natural gas. For electricity billing, choose a Retail Electric Provider (REP) in Texas's ERCOT deregulated market. For all service work, coordinate with Oncor for electricity and Atmos Energy for gas.

Does Allen require a Homeowner's Affidavit for permit work?

Yes. Homeowners performing their own permitted work (without hiring a licensed contractor) must complete a Homeowner's Affidavit before starting. This is required for DIY projects in Allen and is submitted through the CSS portal.

North Texas post-tension slabs — what every Allen homeowner must know

Post-tension slabs are the dominant foundation type throughout the DFW metroplex, and Allen is no exception. Allen's housing stock — primarily built from the mid-1980s onward during the city's rapid suburban growth — was constructed almost universally on post-tension slab foundations. The North Texas black cotton clay soil is extremely expansive, swelling and shrinking significantly with seasonal moisture changes. Post-tension slabs resist this clay movement better than conventional slabs by using high-strength steel tendons embedded in the concrete and tensioned after curing.

The renovation consequence: there is no below-floor access to plumbing in Allen homes. Every drain pipe runs through or below the concrete slab. When any drain must be relocated, the slab must be saw-cut. Before any slab cutting in Allen, a ground-penetrating radar (GPR) specialist must scan the slab to map post-tension cable locations. The plumber then designs the saw-cut path between cables, never through them. Cutting a PT cable releases the tendon's tension suddenly, causing immediate slab cracking or failure in the affected area — a serious structural event, not a cosmetic issue. The GPR scan ($400–$800) is a mandatory cost that prevents a far more expensive structural repair. Contact the City of Allen Building and Permitting Division at (214) 509-4130 for permit questions related to plumbing work in Allen's PT slab environment.

HOA architectural review in Allen TX — the two-approval reality

Allen, Texas is one of the most heavily HOA-governed communities in North Texas. The city's post-1985 development pattern — characterized by master-planned subdivisions with community amenities — resulted in nearly every Allen neighborhood having a homeowners association with an architectural review board. For homeowners, this creates a two-approval reality: city permit approval and HOA architectural approval are both required for most exterior construction and renovation projects, and they are entirely independent processes.

The HOA approval process in Allen typically involves submitting a written request with design plans, materials specifications, and product samples to the HOA's architectural review board. Review timelines vary by community: some HOAs complete review in 1–2 weeks; others may take 30–45 days. The city permit process through the CSS portal runs in parallel but cannot substitute for HOA approval. A city-approved permit does not grant permission to violate HOA rules, and HOA approval does not substitute for a city permit. Both must be obtained independently. Contact the City of Allen Building and Permitting Division at (214) 509-4130 for permit guidance, and contact your HOA directly for architectural review requirements and timelines.

City of Allen Building &