Check Permit Requirements for Your Houston Property
Properties inside the City of Houston are reviewed by Houston Public Works against the Infrastructure Design Manual (IDM), which sets detailed rules for drainage, detention, impervious cover, and site development. Houston's permit portal, plan-review process, and adopted codes differ from unincorporated Harris County just outside the city. ALFAP TX checks the verified address to confirm whether the property is inside Houston and identifies the engineering considerations the IDM may raise.
Preliminary guidance only. ALFAP TX is an informational screening tool. Results are not an official agency determination, FEMA determination, permitting authority confirmation, survey, legal opinion, engineering opinion, inspection, signed or sealed engineering report, or guarantee of approval. Requirements must be confirmed with the applicable authority and, when appropriate, a licensed Professional Engineer.
What this check reviews
Inside Houston confirmation
Whether the verified address appears inside the City of Houston, which means Houston Public Works likely reviews the permit.
IDM-relevant considerations
Drainage, detention, impervious cover, and site-development elements that the Houston Infrastructure Design Manual commonly addresses.
Flood and drainage
The mapped FEMA flood zone and whether drainage or detention calculations appear relevant for a Houston site.
Understanding your result
Houston Public Works likely
If the site is inside Houston, the city reviews the permit and applies the IDM. Confirm with Houston Public Works before submitting, and confirm the property is not in an ETJ handled differently.
IDM drainage rules
The IDM sets detention, runoff, and impervious-cover requirements that differ from county rules. A Texas civil engineer designs to the IDM criteria for Houston projects.
County vs city
If the address is not inside Houston, the project may fall to Harris County Engineering. ALFAP TX points you to the Harris County permit check for county-specific guidance.
When you may need an engineer
- Your Houston project needs a site plan or drainage calculations that meet the IDM.
- The site is in a mapped flood zone and a floodplain development permit may be required.
- You need detention, grading, or utility plans for a Houston building permit submittal.
- You want help navigating Houston's permit portal and plan-review comments.
Frequently asked questions
Who reviews building permits inside the City of Houston, Texas?
Property inside the City of Houston is reviewed by Houston Public Works under the Infrastructure Design Manual. ETJ and unincorporated areas may be handled by Harris County Engineering instead. ALFAP TX identifies the likely reviewer from the verified address, but confirm with Houston Public Works or the county before submitting.
What is the Houston Infrastructure Design Manual (IDM)?
The IDM is the City of Houston's design standard for site development, drainage, detention, impervious cover, and related infrastructure. Projects inside Houston must meet IDM criteria. A Texas civil engineer prepares the plans and calculations that demonstrate IDM compliance for your project.
How do Houston drainage rules differ from Harris County rules?
Houston applies the IDM through Houston Public Works with its own detention and runoff thresholds, while unincorporated areas follow Harris County Engineering criteria. The two are not interchangeable. A civil engineer designs to the criteria that apply at the verified property location.
Is my Houston property in a FEMA flood zone?
Many Houston properties are in mapped FEMA flood zones because of the city's flat terrain and bayou network. ALFAP TX looks up the mapped flood zone at the verified address and reports the source and retrieval date. Confirm official flood status with FEMA and the Houston floodplain administrator.
What engineering might a Houston project need?
A Houston project may need a site plan, drainage and detention calculations to the IDM, grading plans, utility design, floodplain documentation, or structural engineering. ALFAP TX flags which services may be relevant; a Texas-licensed Professional Engineer confirms the actual scope for your project.
Other ALFAP TX preliminary checks
Related Alfa Engineering services
When your result suggests engineering may be relevant, these Alfa Engineering services may apply. A Texas-licensed Professional Engineer confirms the actual scope for your project.