Most adu / garage conversions projects don't fail because a contractor made one dramatic error — they fail because small, cheap-looking decisions stack up.
These are the mistakes we see most often on Houston jobs, and the ones we vet every scope against before we start.
1. Not checking deed restrictions and HOAs
Houston has no zoning, but deed restrictions frequently prohibit ADUs. Confirm in writing before design.
2. Sharing HVAC with the main house
Sharing almost always leaves the ADU hot and humid. A dedicated mini-split is the right answer.
3. Skipping the sub-panel
No sub-panel means every future service call touches the main house. Add one during the conversion.
4. Ignoring slab moisture
Garage slabs have no vapor barrier. Flooring installed on untreated slab cups and delaminates.
5. Missing egress windows
Any sleeping room needs code-sized egress. Retrofitting means cutting the wall or slab later.
6. Under-insulating the roof
A former garage roof rarely has adequate insulation. It cooks the room without a full upgrade.
7. Poor sound isolation
Owners regret hearing the ADUs TV in the main bedroom. Resilient channel and mineral wool solve it once.
8. No dedicated water shutoff or cleanout
Shared plumbing turns a small leak into a whole-house shutdown.
9. Weak entry weatherproofing
Uncovered, unflashed entries account for the majority of ADU water callbacks.
10. Skipping the permit
Unpermitted ADUs cant be legally rented and torpedo appraisals.
How to vet your contractor
Read your adu / garage conversions bid line by line and ask which of these mistakes are being avoided — in writing. A contractor who welcomes the question is the one you want; a contractor who deflects is the one to walk away from.
If you'd like a second set of eyes on a scope of work or an existing bid, we're happy to walk through it with you.
