Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Bee Cave
A home addition or ADU in Bee Cave typically runs $45,000 to $130,000 for a room addition, and $90,000 to $220,000 for a detached ADU, depending on square footage, site work, and finish level. That’s the honest range before anyone steps foot on your lot. What most companies won’t tell you is that a Bee Cave address changes the math before the first footing goes in, because impervious cover caps and bedrock excavation hit this market harder than almost anywhere else in the Austin metro. Tom Barrett and his sons have cut enough Austin Chalk in the 78738 to tell you exactly where the money goes. Call (877) 610-1318 and we’ll walk your lot, run the numbers, and hand you a written scope and price before you commit to anything.
Why Barrett & Sons Construction Is Bee Cave’s Preferred Home Additions & ADU Company
Founded in 1998 and owner-operated by Tom Barrett, Barrett & Sons Construction isn’t a franchise dispatching strangers in a rented van. Tom’s sons run the crews, and Tom’s name, address, and license number are published and verifiable. Ask anyone on your street, or look up the license number yourself; that’s the level of accountability people in Bee Cave expect when they’re writing a six-figure check for an addition.
Our reputation around Bee Cave comes from doing exactly what the contract says. Every scope, every allowance, every price change arrives as a written change order before work happens. No surprise invoices at the end. The permit inspector works for you, not for us; that’s why we like him. We pull permits and get inspections signed on every eligible job, because the last contractor most Bee Cave homeowners used told them permits were optional. They aren’t, especially in a city that tracks impervious cover at the parcel level.
Our crews are background-checked and uniformed on every visit, and a live person answers the phone 24/7, not a voicemail box or an out-of-state call center. When you call about your Bee Cave project, you reach someone who knows what a Balcones Escarpment lot does to a foundation bid. That local knowledge isn’t a talking point; it’s the difference between a permit that gets approved and one that gets bounced back.
Our Home Additions & ADU Services in Bee Cave
ADU Design & Permitting
Before you dream too far into a detached ADU off your Bee Cave lot, someone has to calculate your parcel’s impervious cover. Bee Cave enforces some of the strictest caps in the Austin metro; often 20 to 30 percent depending on zoning, and that cap applies to the total of every roof, driveway, patio, and walkway already on the property. We run that calculation first, before design starts, because adding a 600-square-foot ADU usually means removing or converting existing hardscape to stay under the cap. Our team handles the site survey, the impervious cover worksheet, the architectural drawings, and the permit package as one scope, so the design you approve is a design the city will actually sign off on.
Garage Conversion ADU
Converting an attached garage into an ADU in Bee Cave is often the smartest path to rental income or a mother-in-law suite, and it runs $30,000 to $80,000 in this market. The catch is that Bee Cave’s planning department still counts the converted footprint and any added utility connections toward your impervious cover and site plan review. A garage conversion that triggers a full permit review means wall insulation upgrades, dedicated HVAC, egress windows, and often a separate electrical subpanel. We’ve taken several Bee Cave garage conversions from bare studs to signed-off ADUs, and the paperwork trail on every one of them included a written change order for anything that shifted mid-job. An allowance that isn’t on paper is a surprise waiting for a date.
New Detached ADU
A ground-up detached ADU in Bee Cave sits on solid Austin Chalk and Edwards limestone, not the soft clays of eastern Austin. That means your foundation won’t shift much over time, which is a real advantage. It also means excavation for footings, utility trenches, and drainage lines is a rock-cutting operation, and that shows up as a significant line item. Expect a new detached ADU to run $90,000 to $220,000 in 78738, with the spread driven by square footage, utilities, and how much bedrock has to come out. We build them with materials you can look up: GAF and CertainTeed on the roof, Andersen or Marvin on windows, and premium hardscape brands like Techo-Bloc when patios or walkways are part of the plan.
Junior ADU & Interior Conversion
A junior ADU, or JADU, converts existing interior space like a large bonus room, finished basement, or attached studio into a self-contained living unit with its own entrance, kitchenette, and bath. In Bee Cave, where most homes are 2000s-era Hill Country builds with open plans and generous square footage, a JADU is often the lowest-cost way to add a rental unit without touching the lot’s impervious cover math at all, since the conversion happens inside an already-permitted footprint. Interior conversions typically fall between $45,000 and $130,000 depending on plumbing runs, kitchenette scope, and whether you need a separate entrance cut into an exterior wall. We handle the design, the permit package, and the build, with written change orders for every scope adjustment.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Bee Cave
When we build an ADU or addition in Bee Cave, we install materials you can look up, not mystery brands off a van. That means Techo-Bloc and Cambridge Pavers on driveways, walkways, and permeable hardscape conversions; Quikrete and Oldcastle for concrete and masonry work when the site plan calls for it. Using named premium brands matters doubly in Bee Cave, where permeable pavers often replace existing impervious patio square footage so your enlarged home footprint still passes the parcel-level cap. We stock what’s needed for 78738 projects and we coordinate delivery around your site’s rock-excavation schedule, so materials don’t sit in the Hill Country sun for three weeks while footings get cut.
Common Home Additions & ADU Problems We See in Bee Cave Homes
These are issues we see on Bee Cave jobs specifically, not boilerplate problems from a national site:
- Impervious cover surprises at permit review. A homeowner bids a detached ADU, gets excited, pays a designer, and the city rejects the site plan because the existing driveway apron and flagstone patio already push the lot past its 25% cap. We run the impervious cover worksheet before design, so the plan you approve is a plan the city approves.
- Bedrock that eats draw schedules. Contractors who quote Bee Cave additions using eastern Austin clay-soil assumptions underbid the excavation, then stall at rough-in when the rock-cutting bill comes due. On a 2015 Hill Country-style home off Hamilton Pool Road, our crew had to cut 18 inches into Austin Chalk bedrock just to set the footings for a 400-square-foot second-story addition. That rock is in the bid or it’s in the change order; either way, it gets paid, and we’d rather put it in writing up front.
- Wind-load failures on final inspection. Bee Cave sits on the Balcones Escarpment in Flash Flood Alley, and a second-story addition must meet specific wind-load ratings on doors, windows, and roof connections. Skipping the rated opening schedule passes framing but fails final sign-off, and the homeowner eats a change order for impact-rated windows after the fact.
- Drainage that was never part of the quote. Fast-draining limestone can funnel stormwater onto a lot within minutes, and both LCRA and the City of Bee Cave enforce stormwater ordinances on new construction and site grading. A compliant addition quote includes drainage calculations and any regrading; a cheap quote leaves them out and lets the first heavy rain find the problem.
Pricing for Home Additions & ADU in Bee Cave, TX
| Project | Bee Cave Market Range |
|---|---|
| Home Addition | $45,000 - $130,000 |
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion | $30,000 - $80,000 |
What moves the number most in Bee Cave is rock excavation. Cutting footings into Austin Chalk or Edwards limestone can add $15,000 or more to a ground-up build, and that line item belongs in the bid, not in a surprise invoice at framing. Impervious cover compliance is the second big cost driver, because bringing your parcel under the cap often means removing and replacing driveway or patio square footage with permeable systems like Techo-Bloc pavers. We give free estimates with written line-item pricing, and we offer a Free Second Opinion on Any Written Estimate, plus a permanent 10% Senior & Veteran discount. Call (877) 610-1318 for your free estimate, and we’ll put the whole scope in writing before you sign.
We Also Serve Cities Near Bee Cave
We work across the Hill Country west of Austin, including Lakeway, Lago Vista, Shady Hollow, and Austin. If you’re in a neighboring city and want the same written-scope, permits-pulled approach, call (877) 610-1318. You can also read more about our Home Additions & ADU services or see how we handle projects specifically in Bee Cave.
Serving Bee Cave, TX - Our Local Coverage Area
We’re based in the Bee Cave 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 - Home Additions & ADU in Bee Cave
How does Bee Cave’s impervious cover cap change the size of an ADU I can actually build?
Bee Cave’s impervious cover cap, typically 20 to 30 percent of your lot depending on zoning, limits the total square footage of all roofs, driveways, patios, and walkways on the property. That means the ADU you can actually build is often smaller than the ADU you want, unless you convert or remove existing hardscape first. We calculate your parcel’s current impervious cover before design starts, then hand you a site plan that passes review. Call (877) 610-1318 and we’ll run the numbers on your lot, free.
What wind-load rating must a second-story addition in Bee Cave meet?
A second-story addition in Bee Cave must meet the wind-load requirements set by the current International Residential Code as adopted by the City of Bee Cave, which on the Balcones Escarpment means rated roof-to-wall connections, rated windows, and often impact-rated doors on street-facing elevations. The exact rating depends on your home’s exposure category and roof height, something the permit office verifies against the structural drawings. A compliant quote from us includes the full wind-load schedule and the product sheets to back it up. Call (877) 610-1318 to get your project scoped with the right ratings the first time.
Why does rock excavation show up as a $15,000 line item on a Bee Cave addition?
Because most of the 78738 sits on Austin Chalk and Edwards limestone, not the expansive clays common east of Austin. Cutting footings, utility trenches, and drainage lines into that rock requires hydraulic breakers and sometimes blasting, and it moves slowly. A $15,000 rock-excavation line item is a realistic, honest cost for a ground-up addition or ADU on a harder Bee Cave lot, and we put it in the bid up front so it doesn’t ambush you at rough-in. Call (877) 610-1318 for an exact quote, and we’ll include a soils review with your estimate.
Can I convert my garage into an ADU without triggering a full permit review?
No. In Bee Cave, converting a garage into an ADU triggers a full site plan review because the converted footprint, new utility connections, and any added hardscape all count against your parcel’s impervious cover cap, and the work requires separate permits for plumbing, electrical, and structural changes. Anyone who tells you a garage conversion can skip permits in Bee Cave is setting you up for a red tag and a devaluation problem when you sell. We pull every permit and sign every inspection, with written change orders if anything shifts. Call (877) 610-1318 to get your conversion on the books properly.
Will a documented wind-load compliant addition lower my home insurance premium?
A documented, wind-load compliant addition can reduce your insurance premium, particularly if the work includes impact-rated windows, doors, and rated roof-to-wall connections, because it lowers the insurer’s wind-loss exposure on a Balcones Escarpment lot. The key word is documented: the inspector’s sign-off and the product sheets are what the carrier wants to see. We hand you the full compliance packet at final inspection, with every rating backed by paperwork. Call (877) 610-1318 and ask us about the compliance documentation we include with every addition and ADU we build in Bee Cave.
Ready to Build Your Home Additions & ADU in Bee Cave?
The free estimate is the first step, and it costs you nothing. We’ll walk your lot, run the impervious cover math, and tell you honestly what a permitted, wind-load compliant addition or ADU will cost in Bee Cave, before you sign anything. Tom Barrett built this company in 1998 on written scopes and signed inspections, and the 90-Day Done Right Promise on every job means one call brings him back if something isn’t right. Call (877) 610-1318 today and get your free estimate from a name you can look up and a face you’ll see again.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Bee Cave since 1998.