ADU Rules in Houston, TX (2026)
ADU rules, permit requirements, size limits, and fees for Houston, TX. Source-cited from official municipal code.
Yes, ADUs are allowed in Houston, TX.
Houston, TX permits accessory dwelling units (ADUs) on residential properties. ADUs — also called granny flats, in-law units, backyard cottages, or secondary suites — are secondary housing units on a single-family or multifamily lot. State and local law governs the approval process. In Houston, the local building department handles ADU permit applications. Below you will find the current size limits, setbacks, fees, and timeline for building an ADU in Houston.
ADU Size Limits
ADU Size Limits in Houston: Detached ADU: up to 1500 sq ft (max height: varies — see official source). Attached ADU: size varies by zoning — see official source. Houston Development Code (Chapter 42) does not impose maximum ADU sizes — this is regulated by deed restrictions in subdivisions that have them. New construction ADUs must comply with building codes (Houston Building Code) and Development Code setbacks and lot coverage standards.
| Type | Max Size | Max Height |
|---|---|---|
| Detached ADU | 1500 sq ft · Verified May 20, 2026 · Source | See official source |
| Attached ADU | See official source | See official source |
Permit Fees
ADU Permit Fees in Houston: Plan check fee: Varies. Building permit fee: Varies. Impact fees: None. School fees: None or N/A. Total estimated permit cost: Varies.
| Fee Type | Amount |
|---|---|
| Plan Check | $100–$1,000 |
| Building Permit | Based on construction value — typically $500–$3,000 |
| Impact Fees | None |
| School Fees | None |
| Total Estimate | See official source |
Permit Timeline
Houston ADU Permit Timeline: Permit timeline has not been confirmed — contact the department for current processing times. Apply through the local building department online permit portal. Contact them through their official website for current contact information.
Setback Requirements
ADU Setback Requirements in Houston: Front setback: follows zone standard. Side setback: no minimum. Rear setback: no minimum.
Parking Requirements
Parking Requirements: When a second dwelling unit of not more than 1000 gross square feet is provided, no additional off-street parking spaces shall be required.
Restrictions & Requirements
- Deed restrictions in your subdivision may prohibit or regulate ADUs — check with Harris County Deed Records
- Houston Development Code building line (setback) from street must be maintained
- Building Code habitability requirements apply (ceiling height, egress, ventilation, electrical)
- FEMA floodplain regulations apply — approximately 50% of Houston is in or near flood zones
- Drainage requirements under City of Houston Drainage Code
- If subdivision has HOA, deed restrictions are privately enforceable
How Many ADUs Are Allowed?
Number of ADUs Allowed in Houston: Single-family lots: not confirmed — see official source. Multifamily properties: not confirmed — see official source.
- Single-Family Lots
- No limit established by code — deed restrictions may restrict
- Multifamily Properties
- No limit established by code — deed restrictions may restrict
Statewide Preemption
ADU Preemption
We could not confirm a statewide ADU preemption statute for Texas.
View Texas preemption detailsFrequently Asked Questions
Can I build an ADU in Houston?
Yes. Houston, TX allows accessory dwelling units. On a single-family lot you can build No limit established by code — deed restrictions may restrict.
How big can an ADU be in Houston?
The maximum size for a detached ADU in Houston is 1,500 square feet.
How long does it take to get an ADU permit in Houston?
The typical ADU permit timeline in Houston is Houston Permitting Center (HPC) building permit: typically 2-6 weeks for residential construction. Houston uses an automated permit system for many standard construction types.. Total estimated permit fees are $600–$4,000 total permit fees.
Do I need extra parking for an ADU in Houston?
Houston parking rules for ADUs: When a second dwelling unit of not more than 1000 gross square feet is provided, no additional off-street parking spaces shall be required.
Do I have to live on-site to have an ADU in Houston?
Owner-occupancy requirement in Houston: No owner-occupancy requirement in Houston for ADUs. Houston does not require the property owner to reside on-site.
Source: Houston City Code Chapter 42 — Development Code; Harris County Deed Restriction Records. Last verified April 8, 2026. View source