ADU in Round Rock, TX
ADU design and permitting in Round Rock starts with a question most other Texas cities don’t require: what does your HOA’s CC&R actually say? Most of Round Rock’s housing stock sits inside master-planned communities built between 1985 and 2015, and those deed restrictions often override what city zoning would otherwise allow. Add Williamson County’s separate permitting path and the expansive clay soils under most lots, and a Round Rock ADU is a different project than the same square footage in Austin. Call (971) 497-2402 for a written price before any work starts.
Why Round Rock Homes Are Different
Round Rock’s suburban pattern creates a two-tier ADU market. In Teravista, Stone Canyon, and the Brushy Creek corridor, HOAs hold architectural review authority that functions as a first permit office. Their CC&Rs frequently ban accessory structures over a set square footage or any unit with independent kitchen facilities, and no Round Rock city permit overrides that. Homeowners call us after reading about Austin’s 2019 ADU deregulation, not realizing those reforms never crossed the city line. Round Rock is a separate municipality under Williamson County with its own code.
Older blocks near historic downtown Round Rock, the pre-1970s bungalows and cottages, are where detached or attached ADUs move without an HOA fight. But the lots are small and the infrastructure is aging, so what you gain in zoning freedom you spend on utility upgrades. Beneath all of it sits Central Texas black clay, which heaves and shrinks with every wet-dry cycle. Any detached ADU in Round Rock needs an engineered slab or pier-and-beam system, and that foundation line item catches most first-time clients off guard. Summer heat is the other constant: undersized HVAC is the single most common post-occupancy complaint we hear from detached ADU owners across Round Rock.
Our Main Round Rock Services
Two services generate most of the calls we receive from Round Rock homeowners, and each has its own dedicated page with full local pricing and detail.
Garage Conversion ADU in Round Rock
Most Round Rock garages from the 1990s and 2000s were built as unconditioned spaces on slabs poured to residential standard, not secondary-dwelling standard. A conversion means checking that slab thickness, running new electrical from the panel, and often reframing the garage door wall. HOA restrictions frequently govern this more tightly than a detached build because the structure already exists within the original architectural envelope. See the full scope and Round Rock pricing on our Garage Conversion ADU in Round Rock page.
New Detached ADU in Round Rock
A new detached ADU in Round Rock lives or dies on the foundation design. Expansive clay means an engineered slab or pier-and-beam is non-negotiable, and that’s before you touch framing, HVAC sizing, or utility laterals. HOA setbacks and architectural review add a layer that does not exist in unincorporated Williamson County. We quote the entire project, drawings through final inspection, at one written price. Read the full breakdown on our New Detached ADU in Round Rock page.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
ADU Design & Permitting in Round Rock
ADU Design & Permitting in Round Rock is where the project wins or loses before a shovel hits the dirt. The drawings have to satisfy three authorities at once: the City of Round Rock, Williamson County, and in most subdivisions, an HOA architectural review board whose restrictions can ban the unit outright. Our design-build studio produces the permit set as the core product, not a formality. That means a single set of drawings that holds up across all three reviews, with no designer-versus-builder gap when a correction comes back. This work is covered under our ADU Design & Permitting practice.
Site Assessment
Signs you need it
Your lot slopes more than you expected, utility hookups are on the far side of the house, or your HOA’s CC&R language on accessory structures is ambiguous.
What it costs in Round Rock
A site assessment in Round Rock typically runs $450-$1,500 as a standalone survey and feasibility review, and this is credited back against the design contract when you move forward.
How we do it
We pull the plat, walk the lot with a measuring wheel and grade readings, map existing utility laterals, and hand you a written feasibility memo before any design hours are billed.
Permit Application
Signs you need it
You already have drawings but they came back with corrections, or you are starting from zero and want one entity accountable for the entire filing.
What it costs in Round Rock
Permit application and management in Round Rock typically runs $1,200-$3,500 depending on whether we are working from our own drawings or correcting someone else’s.
How we do it
We assemble the full submittal, file with the City of Round Rock and any Williamson County requirements, track review cycles, and document every correction in writing.
What ADU Design & Permitting Costs in Round Rock
| Item | Typical range in Round Rock |
|---|---|
| Full design and permit set for a detached ADU | $8,000-$20,000 |
| Full design and permit set for a garage conversion | $5,000-$12,000 |
| Permit application and management | $1,200-$3,500 |
Will the design-and-permit phase cost more if Round Rock or the HOA requests revisions?
No. The written price covers the permit set through approval, including correction cycles from the city and your HOA’s architectural review board. We document every comment and response. Call (971) 497-2402 for an exact written price on your project.
How do you handle a Round Rock HOA that bans ADUs?
We read the CC&R first, before any design hours. If the restriction is clear, we tell you in writing and stop there. If language is ambiguous or a variance path exists, the permit set is drafted to support that application.
Junior ADU & Interior Conversion in Round Rock
Junior ADU and interior conversion work in Round Rock is the quiet path around the HOA problem. Because a JADU lives inside the existing footprint of the home, many CC&Rs that ban detached accessory structures are silent on interior conversions. Older homes near historic downtown Round Rock with underused formal living rooms or oversized utility spaces are the strongest candidates. The trade-off is mechanical: those pre-1970s houses were never wired or ducted for a second kitchen or separate climate zone. This is our Junior ADU & Interior Conversion specialty.
Room-to-ADU Conversion
Signs you need it
You have a formal dining room, oversized den, or finished basement space that has not been used for its original purpose in years.
What it costs in Round Rock
A room-to-ADU conversion in Round Rock typically runs $45,000-$85,000, with the lower end reflecting minimal plumbing and the upper end reflecting a full kitchen rough-in.
How we do it
We verify the existing framing and subfloor, design the new kitchen and bath within the current footprint, and run mechanicals in ways that preserve the original structure.
Interior JADU
Signs you need it
You want rental income or a relative housing solution but your HOA bans any exterior construction or accessory structure.
What it costs in Round Rock
An interior JADU in Round Rock typically runs $35,000-$60,000, and because no foundation or roof work is involved, it avoids the clay-soil cost multiplier entirely.
How we do it
We file for a JADU under the applicable code path, add a kitchenette and independent entrance where the floor plan allows, and keep every wall line inside the original envelope.
What Junior ADU & Interior Conversion Costs in Round Rock
| Item | Typical range in Round Rock |
|---|---|
| Interior JADU | $35,000-$60,000 |
| Room-to-ADU conversion | $45,000-$85,000 |
| Attached addition ADU | $80,000-$150,000 |
Does a Round Rock HOA need to approve an interior JADU?
Usually not, because the work is interior and invisible from the street. But we always pull the CC&R language and confirm in writing before the permit set goes in. Call (971) 497-2402 for a written price on your floor plan.
Can an older Round Rock home handle the extra electrical load?
Many pre-1970s homes near downtown Round Rock run on 100-amp panels. A JADU with a kitchenette typically requires a panel upgrade, which we scope and price in the original written quote.
ADU Site Prep & Utilities in Round Rock
ADU Site Prep & Utilities in Round Rock is where the black clay under your lot stops being an abstraction. Expansive soil moves enough between wet and dry seasons to crack a slab poured without an engineered soil report, and our site prep work starts with that reality. Water, sewer, and electrical laterals in older Round Rock neighborhoods are frequently shallow or undersized for a second dwelling. We scope every utility path and foundation line item in the same written price as the build itself. This falls under our ADU Site Prep & Utilities practice.
Foundation & Grading
Signs you need it
Your site drains toward the proposed ADU footprint, your soil report shows high plasticity clay, or your existing home has visible slab movement.
What it costs in Round Rock
Foundation and grading for a Round Rock detached ADU typically runs $15,000-$40,000 depending on pier depth, engineered fill, and whether a soil report is already on file.
How we do it
We order the geotechnical report, design the engineered slab or pier-and-beam system to match the clay conditions, and cut and fill to move water away from the structure.
Electrical Panel Upgrade
Signs you need it
Your panel is 100 amps or less, the ADU will have an electric range or mini-split HVAC, or the new subpanel run is longer than 50 feet.
What it costs in Round Rock
An electrical panel upgrade and feeder run for a Round Rock ADU typically costs $3,000-$8,000 depending on panel size, conduit path, and whether the city requires a disconnect at the street.
How we do it
We size the new service to the ADU’s actual load calculation, pull the permit, and run the feeder in conduit sized for future capacity rather than minimum code.
What ADU Site Prep & Utilities Costs in Round Rock
| Item | Typical range in Round Rock |
|---|---|
| Foundation and grading for a detached ADU | $15,000-$40,000 |
| Electrical panel upgrade and feeder | $3,000-$8,000 |
| Plumbing lateral trench and hookup | $6,000-$18,000 |
What depth do Round Rock water and sewer laterals need?
Round Rock follows Williamson County requirements for freeze and cover depth, but the bigger variable is the clay. Shallow or non-bedded laterals shift more, so we bed all new utility runs in select fill. Call (971) 497-2402 for a site-specific written quote.
Can you handle the foundation and utilities while leaving the build to someone else?
Yes. We offer site prep as a standalone scope with its own permit set and written price. You own the documentation for every line item, whether we build the ADU itself or not.
Brands We Service in Round Rock
We specify and coordinate prefab and modular ADU systems from Abodu, Cover, and Dvele, plus James Hardie siding where the HOA architectural standards require it. Parts and panel orders are scheduled around your site prep so no delivery sits on site through a rainy clay swell. See our brands for the full list.
Pricing for ADU in Round Rock, TX
| Service | Typical range in Round Rock |
|---|---|
| Full design and permit set for a detached ADU | $8,000-$20,000 |
| Full design and permit set for a garage conversion | $5,000-$12,000 |
| Permit application and management | $1,200-$3,500 |
| Site assessment | $450-$1,500 |
| Interior JADU | $35,000-$60,000 |
| Room-to-ADU conversion | $45,000-$85,000 |
| Attached addition ADU | $80,000-$150,000 |
| Foundation and grading for a detached ADU | $15,000-$40,000 |
| Electrical panel upgrade and feeder | $3,000-$8,000 |
| Plumbing lateral trench and hookup | $6,000-$18,000 |
| Above-garage ADU | $120,000-$220,000 |
| Basement ADU | $70,000-$130,000 |
Prices in Round Rock run higher than the Texas average for two reasons: expansive clay soil forces engineered foundations on detached builds, and HOA architectural review often adds revision cycles to the permit phase. Every price above is a range, and every project we quote gets a written price before any work starts, per Haven Standard Clause 1.
Neighborhoods We Serve in Round Rock
We serve the full Round Rock area, from the HOA-governed subdivisions to the older blocks where ADUs face fewer deed-restriction hurdles. Response time for estimates is typically within two business days anywhere in the city.
- Teravista
- Stone Canyon
- Brushy Creek corridor
- Historic downtown Round Rock
- Walsh Ranch-adjacent communities
Service Area - Cities Near Round Rock
From our Austin metro office, crews serve Round Rock and the surrounding cities daily. We also cover Pflugerville, TX, Cedar Park, TX, Leander, TX, and Austin, TX with the same written-price standard and the same 365-Day Done Right Promise.
Serving Round Rock, TX - Our Local Coverage Area
We’re based in the Round Rock area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU in Round Rock
A detached ADU in Round Rock typically takes 10 to 16 months from first design meeting to final inspection. The HOA architectural review and soil-related foundation engineering add time compared to unincorporated Williamson County. We document every phase in writing so you can track the schedule against the permit set.
In most Round Rock subdivisions, yes. The HOA architectural review board is the de facto first permit authority, and the city will not override a deed restriction. We read your CC&R before any design hours are billed and tell you in writing if the project is viable.
We do. The City of Round Rock permit set, any Williamson County requirements, and HOA architectural submittals are handled as one package under a single written price. You receive copies of every filing and correction.
Call (971) 497-2402 to schedule a free estimate or send us the written quote you already have for a second opinion. We answer with a person, not a queue.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Round Rock Customers Say
"Garage conversion finished on the drawings and close to the schedule. They were honest that the sewer connection was the unknown, and it was."
- Arjun D."The permit set and the build were one contract with one number. Our neighbours used two firms and spent a year watching them blame each other."
- Helena V."The rental income has covered the payment since the second month. They were realistic about the numbers rather than optimistic."
- Odette N.