The difference between a adu / garage conversions project that lasts and one that becomes a callback is almost always in the details that don't show up in a low bid.
These are the specs and design decisions our team insists on for every Houston home — the ones that quietly separate a real professional install from a cheap one.
1. Deed and zoning check before design
Houston has no zoning but deed restrictions and HOAs can prohibit ADUs. Confirm in writing before spending on plans.
2. Separate HVAC system
Sharing the main houses system almost always leaves the ADU muggy. A ductless mini-split is the right answer 9 times out of 10.
3. Independent electrical sub-panel
A dedicated sub-panel makes future metering, rental separation, and troubleshooting straightforward.
4. Slab moisture mitigation
Garage slabs werent poured with vapor barriers. Grind, seal, and install a proper vapor retarder before any flooring.
5. Insulated and sealed garage door opening
If the door stays, insulate it and seal the perimeter. If it goes, frame the opening properly with a header, not just infill.
6. Egress-compliant bedroom windows
Any sleeping room needs a code-sized egress window. Retrofitting later means cutting the slab or exterior wall.
7. Independent water shutoff and cleanout
A dedicated shutoff and drain cleanout make the ADU serviceable without touching the main house.
8. Sound isolation from the main home
Resilient channel or double drywall on shared walls keeps the ADU rentable and the main house peaceful.
9. Weatherproofed exterior entry
A covered, drained entry with proper flashing prevents the #1 ADU callback: water at the threshold.
10. Address, mailbox, and utility separation
Even if you never rent it, separating utilities and getting a unit number keeps future options open.
The bottom line
Any of these can be skipped to hit a lower price — and every one of them will show up as a problem within a few years. Ask any contractor bidding your adu / garage conversions project which of these are included, in writing. The honest ones welcome the question.
If you'd like to walk through what these look like on your specific home, our team is happy to do a no-pressure consultation.
