Georgetown ADU Builders: Custom Backyard ADUs, Casitas, In-Law Suites & Garage Conversions for Residential Properties
Georgetown ADU Builders brings master architectural design and turnkey construction experience to custom detached ADUs, attached in-law suites, garage conversions, and multi-generational casitas across Georgetown and Williamson County, Texas.
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Strict structural & energy code compliance
Sub-2cm LIDAR laser property mapping
Foundation post-tension slab protection
From 3D design to final city permit
Complete ADU Construction & Architectural Services
From detached backyard cottages to garage conversions and city permit submittals, explore our end-to-end accessory dwelling unit solutions.
Custom ADU Architectural Design & 3D Visualization
3D floor plans, site elevations and construction drawings for an ADU, drawn to the Georgetown UDC setbacks that apply to your lot.
- 3D floor plans and elevations you can walk through before framing starts
- Site plan drawn to the Georgetown UDC setbacks for your zoning district
- Rock depth and lot slope carried into the foundation design
Detached ADU & Backyard Casita Construction
Standalone guest houses, granny flats, casitas and backyard cottages on their own foundation, sited around Georgetown's rock and setback limits.
- Foundation designed after we know how deep the limestone sits
- Utility trenching priced against rock, which is where these budgets move
- Ductless mini-split heating and cooling, zoned to the unit
Garage Conversion ADU Remodeling
Attached and detached garage conversions turned into rentable studio or 1-bedroom ADUs, using a slab and roof that already exist.
- Slab checked for moisture and level before anything is built on it
- Garage door opening framed and infilled with windows, not a flat blank wall
- Plumbing trenched through the slab for the kitchen and bathroom
Attached ADU Construction & Home Addition
In-law suites and mother-in-law additions tied into the existing foundation and roofline, with a private entry and a door through to the main house.
- New foundation doweled into the existing one so the two move together
- Double-stud wall between households, because sound is what people regret
- Masonry, stone and roofline matched to the original elevation
Multi-Bedroom & 2-Story ADU Construction
2-bedroom and 3-bedroom detached ADUs for family living or rental income, on lots where setbacks and footprint rule out spreading out.
- Deeper footings sized for two-storey load, and for what the rock allows
- Engineered I-joists and LVL beams through the upper floor
- Separate climate zones so bedrooms and living space run independently
ADU Permitting, Zoning & Feasibility Services
City submittal packages, site plan review, Georgetown UDC zoning checks and easement audits — the work that decides whether an ADU is possible at all.
- Georgetown UDC zoning check on your specific parcel
- Easements and utility mainline depths confirmed before design begins
- Historic Overlay review identified early where the parcel is inside one
Engineered for Central Texas Geology & Thermal Demands
Building lasting accessory dwelling units requires more than standard framing practices. Central Texas Vertisol black clay soils experience continuous shrink-swell movement throughout rain and drought cycles. Without specialized foundation design, unreinforced concrete slabs crack and warp over time.
Post-Tension Foundation Slabs
Monolithic concrete pours integrated with high-tensile steel cables engineered to float above expansive clay.
Thermal Envelope Security
Closed-cell spray foam, radiant barrier decking, and Low-E window assemblies built for 100°F+ summer heat spikes.
Verified ADU Construction Benchmark
- ASTM C109 Concrete Standard: High-compression strength verified on every foundation pour.
- Acoustic Isolation (STC 55+): Sound-dampening channels and staggered studs on attached suites.
- High-SEER2 Heat Pumps: Multi-zone ductless mini-split HVAC climate control.
- 100% City Code Pass Rate: Full compliance with IRC 2021 and Georgetown Unified Development Code (UDC).
Frequently Asked Questions About Georgetown ADUs
Authoritative answers to common questions about cost, permitting, and construction.
What is the average cost to build a detached ADU in Georgetown, TX?
Turnkey detached ADU construction in Georgetown ranges from $130,000 to $320,000 depending on square footage, post-tension foundation engineering required for Vertisol clay soil, and luxury finish selections.
What are the zoning rules and max square footage for ADUs under Georgetown UDC?
Under the City of Georgetown Unified Development Code (UDC), detached ADUs on residential single-family lots generally allow up to 1,000 sq ft or 50% of the primary dwelling unit footprint (whichever is less), requiring a 5-foot side and rear setback.
How long does it take to design and build an ADU in Georgetown?
Two phases, and they behave differently. Design and permitting run first — the Georgetown UDC zoning check, the survey and the city plan review — and that phase is paced by paperwork rather than by weather or trades. Construction follows, and on Georgetown lots the largest variable is how deep the limestone sits, because rock drives both the foundation design and the utility trenching. Any schedule quoted before someone has stood on the lot is an estimate rather than a commitment; we set real dates in the proposal, after the site visit.
Do ADUs require separate electric and water meters in Williamson County?
While city building codes permit sub-metering from the primary residence, dedicated electric sub-panels and separate water meters are recommended for independent long-term rental accounting and tenant billing.
Why are post-tension foundation slabs mandatory for Georgetown ADUs?
Georgetown and Williamson County feature expansive Vertisol black clay soils that experience severe shrink-swell cycles. Post-tension slabs use high-tensile steel cables embedded in concrete to prevent foundation warping, floor unlevelness, and drywall cracking.
What monthly rental income can a backyard ADU generate in Georgetown?
A well-designed 1-bedroom or 2-bedroom backyard ADU in Georgetown typically commands between $1,400 and $2,200 per month in passive rental income, providing strong long-term cash flow and immediate property equity.
Can I build an ADU or in-law suite in an HOA community like Sun City or Berry Creek?
Yes, provided the exterior architecture, roofing materials, and exterior paint match the primary residence. We prepare full Architectural Control Committee (ACC) submittal packages to ensure seamless HOA approval.
What is the best HVAC system for an accessory dwelling unit in Texas heat?
Multi-zone ductless mini-split heat pump systems (rated 20+ SEER2) are the industry benchmark for Central Texas ADUs, offering whisper-quiet independent room temperature control and up to 40% lower energy costs.