Houston ADU permit requirements
Last reviewed: June 22, 2026
Quick answer
Permitting an accessory dwelling unit (ADU) in Houston, Texas means pulling a building permit from the local authority that issues it. ArchPermit tracks 16 source-cited requirements (11 required, the rest conditional) for this jurisdiction. Submittals go through iPermits + ProjectDox online portal. These requirements were last reviewed June 22, 2026; confirm the exact forms and fees with the local permitting authority.
A source-cited checklist of what an ADU (accessory dwelling unit) permit package needs in City of Houston. Every item links to its authoritative source; items that vary are flagged to confirm locally.
Houston has no zoning, so an ADU (the City's term is 'auxiliary unit (ADU)'; commonly 'garage apartment' or 'quarters') is broadly allowed and governed by Code of Ordinances Chapter 42 (development/platting — property use and setbacks) plus private recorded deed restrictions, rather than by a zoning district. Planning reviews the site plan for Chapter 42 (use, setbacks), Chapter 26 (parking), and Chapter 33 (trees). Platting/replat may be triggered by a change in use. ADU carve-outs: no landscaping requirement, and parking is scaled to ADU size (≤1,000 sf living = no added space). The exact ADU setback and size cap live in Chapter 42 — confirm there.
- Building Permit Applicationrequired
Completed online via the iPermits portal.
source · reviewed 2026-06-22 - Calculation of Impervious Percentage (CE-1207)required
Impervious-cover calculation; also drives whether a Storm review is triggered (>65% impervious cover, or lot >15,000 sf).
source · reviewed 2026-06-22 - Complete Plan Setrequired
Construction-ready plans uploaded to ProjectDox; sheets may not be marked 'Preliminary' / 'Not for Construction.'
source · reviewed 2026-06-22 - Deed Restrictions Declarationrequired
Signed by the property owner and validated against HCAD; if ownership doesn't match HCAD, also upload proof of ownership.
source · reviewed 2026-06-22 - Door & Window Schedule + Wall Schedulerequired
List door/window sizes; key the wall schedule to the floor plan for all wall types; include energy-code details.
source · reviewed 2026-06-22 - Energy Code Documentsrequired
IC3, REScheck, or REM/Rate output matching the plans, or prescriptive energy requirements shown on the plans.
source · reviewed 2026-06-22 - Floor Plans (rooms labeled by use)required
Each room labeled by use, with partitions, windows, doors, and scope-of-work details.
source · reviewed 2026-06-22 - Grading Permits Worksheet (CE-1094)required
Grading/fill worksheet for the project.
source · reviewed 2026-06-22 - Site Planrequired
Always required — all buildings, off-street parking, and impervious areas, with dimensions matching the plat and survey.
source · reviewed 2026-06-22 - Stormwater Information Formrequired
Required for construction, additions, and sitework; completed/signed by the owner.
source · reviewed 2026-06-22 - Wastewater Capacity Reservation (WCR) Letterrequired
Water/sewer letter required for all new single-family residential construction; obtained separately via iPermits before plan approval.
source · reviewed 2026-06-22 - Access Agreement for Construction and Maintenanceconditionalverify locally
Required if proposed construction is less than three feet from an adjacent single-family residence's property line (the governing setback figure lives in Chapter 42 — confirm).
source · reviewed 2026-06-22 - Elevation Certificate (floodplain)conditional
Required if the lot is in the 100-yr or 500-yr floodplain; sealed by a Texas surveyor or PE (a Mitigation Plan is also required).
source · reviewed 2026-06-22 - Sealed Structural / Architectural Sheetsconditional
Structural/architectural sheets sealed, signed, and dated by a Texas-licensed architect or engineer when required (foundation, framing, wall-section, windstrapping details).
source · reviewed 2026-06-22 - Subdivision Plat / Replat Referenceconditional
Required if the property is platted — check building lines, easements, lot size, density. Platting may be required on a change in use.
source · reviewed 2026-06-22 - Survey (Texas Registered)conditional
Required for residential additions / garage conversions — property lines, easements, setback lines, and existing structures (a survey showing a small addition may serve as the site plan).
source · reviewed 2026-06-22