Garage Conversion ADU in Alief - Plans, Permits & Build, One Fixed Price

Fast, Reliable Garage Conversion ADU Across Alief

If you’re weighing a garage conversion ADU in Alief, the number that matters first is this: a turnkey project here typically runs $145,000-$225,000 all-in, drawings through final inspection. That range accounts for the two gates every Alief project has to clear that neighboring cities don’t: Harris County Floodplain regulations and 1970s-era deed restrictions on your specific subdivision. Our team handles both on day one. Call (971) 497-2402 to get your property’s numbers, not the internet’s numbers.

Call (971) 497-2402

We work throughout Alief, from the neighborhoods off Bissonnet north of Brays Bayou to the subdivisions along Dairy Ashford and Kirkwood, and around Alief Community Park. The housing stock here is overwhelmingly 1970s and 1980s ranch-style homes with attached or detached two-car garages, which are exactly the structures our Garage Conversion ADU team converts most weeks. That matters because we already know what your 1978 or 1982 build is hiding before we walk in.

Why Alief Homeowners Choose Ellery ADU Studio

We are a design-build studio, not a contractor who subcontracts the drawings to someone you’ll never meet. The permit set, the engineering for flood elevation and wind load, the construction, and the written warranty all sit inside one contract with one price. If something goes sideways between the drawings and the drywall, there is no designer pointing at the builder and no builder pointing at the designer. That blame gap derails more Alief garage ADU projects than any single code requirement, and we close it by contract.

Since 2015, when the ADU permitting landscape shifted, we have designed, permitted, and built over 900 ADUs. Every one of them had a written price before any work started, under Haven Standard Clause 1. Every one received a documented photo record on every visit. And every one carried the 365-Day Done Right Promise: if the finished ADU is not built to the permitted drawings, we make it right, in writing, before the project starts. Nadia Ellery, our founder, insists on that paper trail because Alief’s flood and deed-restriction realities make this one of the most documentation-heavy ADU markets in Harris County.

Houston-area crews serve Alief locally; dispatch and scheduling are coordinated from our Houston office. We answer calls with a live person 24/7, not a voicemail queue. And if you already have a written estimate from anyone else, bring it to us for a Free Second Opinion. We’ll show you line by line where the quote is strong, where it’s thin, and what it’s missing on flood elevation and wind-load compliance.

Our Garage Conversion ADU Services in Alief

Detached Garage Conversion

Most Alief homes have a detached two-car garage set at the rear of the lot, and in Zone AE that means the existing slab is frequently 1 to 3 feet below BFE. We don’t assume the slab works. We pull the elevation certificate, check the FEMA panel for your exact address, and if needed, convert the design to an elevated pier-and-beam foundation with flood vents rated for Harris County. The flatwork changes, but the result is a conversion that passes the structural inspection on the first visit, not the third.

Attached Garage Conversion

An attached garage in Alief can sometimes avoid a full elevation if the main house finished floor is already at or above BFE and the structure shares a continuous foundation. That is a site-specific call, made only after we see the certificate and the original plat. Homes in subdivisions off Westpark Tollway and Highway 6 often qualify; homes in the Brays Bayou floodway generally do not. We will tell you which one yours is, with the engineering to back the answer.

Garage JADU

A Junior ADU carved from an existing garage bay is often the fastest path if you have a mother-in-law moving in or need rental income without a full second kitchen. In Alief, a JADU can clear deed restrictions more easily than a full detached conversion because some covenants drafted in the 1970s and 1980s permit attached accessory units but not standalone second dwellings. We pull the deed restrictions before we pull the permit. That order, reversed, is the single most expensive mistake we see.

Garage Partition & Bathroom Add

If you need to keep one bay for cars or a workshop and convert the other bay to living space, we partition the garage and add a full bath, kitchenette, and independent entrance. In Alief’s older ranch homes, this usually means running new plumbing under a slab that has shifted over four decades, so the elevation and existing foundation condition dictate the scope. We quote the work with line-item drainage and foundation costs, not a round number that swells later.

Brands and Systems We Specify in Alief

We specify and coordinate James Hardie, Abodu, and Cover systems within the single design-build contract. For Alief’s 140 mph wind-uplift requirement, HardiePlank lap siding and HardieSoffit panels carry the rating when installed to manufacturer spec, and Abodu and Cover prefab modules arrive engineered for Harris County wind loads. We carry local stock of the hardware and sealants those systems require, so a mid-project parts need doesn’t stall your conversion while an inspector waits.

Common Garage Conversion ADU Problems We See in Alief Homes

• Slab below BFE in Zone AE. Many Alief garages were built on slabs poured in the 1970s and 1980s when flood maps looked different. Today in Zone AE, that slab is often 1-3 feet below Base Flood Elevation, and the county will not close the permit until the finished floor is elevated or the design otherwise complies with floodplain rules.
• Deed restriction bans ‘separate residence.’ Private subdivision covenants from the 1970s and 1980s frequently say one dwelling unit per lot. Homeowners who pull a Harris County permit first and read the covenants second can lose engineering fees and months of time on a project the HOA-architect will kill regardless.
• Contractor uses 110 mph wind hardware instead of 140 mph. Houston’s standard wind zone is 110 mph. Alief, under Harris County’s stricter mapping in the Brays Bayou watershed, often requires 140 mph uplift ratings. Standard hurricane clips and framing that pass in Memorial or Bellaire will fail Alief’s structural inspection, and insurance carriers will deny claims tied to a non-compliant ADU.
• Brays Bayou watershed drainage assumptions. Even if your lot is outside Zone AE, the Brays Bayou watershed’s rainfall-runoff model changed after Harvey. Harris County now applies stricter detention and drainage review to any new impervious surface, including a converted garage’s new driveway curb cut or expanded pad unless your design accounts for it up front.

Pricing for Garage Conversion ADU in Alief, TX

We Also Serve Cities Near Alief

We work every day in Alief and regularly bring the same Harris County flood and deed-restriction expertise to homeowners in Sugar Land, Missouri City, Houston, and Cypress. If you’re within a short drive of Alief and evaluating a garage ADU on a property with similar 1970s-80s ranch stock and Zone AE exposure, our Houston-based team can schedule an assessment for your address.

FAQs - Garage Conversion ADU in Alief