Accessory Structures in Mission, TX: What Residents Actually Need to Know

If you live in Mission or are thinking about moving there, accessory structures are one of those things you probably won't think about until they affect you directly. Mission has 3 specific rules on the books covering different aspects of accessory structures, and some of them might surprise you.

ADU Rules

No statewide ADU mandate in Texas. Mission's zoning code (Appendix A) governs ADU allowances. Contact Mission Planning & Zoning to verify what's permitted in your district.

Key details: State Mandate: None — local zoning controls. Code: Mission Appendix A – Zoning. Zoning Check: Verify allowance by district. Contact: Mission Planning & Zoning.

Unpermitted ADUs face stop-work orders and removal or legalization requirements. Fines of $500–$2,000 apply for unpermitted construction. Properties with illegal ADUs may face title issues at sale.

Shed Rules

Accessory structures in Mission require building permits above applicable size thresholds. Setbacks and height limits governed by zoning code.

Key details: Permit: Required above size threshold. Setbacks: Per Mission zoning code. Code: Mission Building Code / Appendix A. Contact: Mission Building Department.

Unpermitted structures receive a notice to either obtain a retroactive permit (with double fees) or remove the structure within 60 days. Fines of $100–$500 apply for non-compliance.

Garage Conversions

Garage conversions require building permits and must comply with Mission's zoning and building codes. Check ADU provisions for potential as additional dwelling.

Key details: Permit Required: Yes — building permit. Code: Mission Building Code / Appendix A. ADU Option: Verify under zoning code. Contact: Mission Building Department.

Unpermitted garage conversions face fines of $500–$2,000, mandatory permit acquisition (double fees), and may need to be restored to garage use if code requirements cannot be met.

The Bottom Line

Mission's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Mission is broadly strict or permissive.

This guide is based on Mission's current municipal code. Local rules can and do change, so check the individual ordinance pages for the latest details, penalties, and FAQs.