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 Lakehills
Home additions and ADU construction in Lakehills typically run $45,000-$130,000 for a room addition, $90,000-$220,000 for a new detached ADU, and $30,000-$80,000 for a garage conversion. The biggest variable isn’t square footage: it’s what’s under your lot. Lakehills sits on Medina Lake, and the Edwards Plateau limestone just below the surface sends excavation costs up fast, while FEMA floodplain rules and Guadalupe-Blanco River Authority shoreline easements can add 4-8 weeks to permitting. We know because we’ve pulled those permits. If you’re planning an addition or ADU on a Lakehills lot, call (877) 610-1318 and we’ll walk the site with you before you spend a dime.
Why Barrett & Sons Construction Is Lakehills’s Preferred Home Additions & ADU Company
Tom Barrett started this company in 1998, and his sons run the crews. That matters in Lakehills because the person who signs your contract is the same person you’ll see in the driveway. We’re not dispatching strangers from a call center. When a Lakehills homeowner calls with a question about their ADU permit or a change order, a live person answers, 24/7.
We’ve worked on lake-view lots off Park Road 37, on steep rocky parcels where the limestone is three inches down, and on 1960s fishing cabins that were never meant to be full-time homes. That local experience changes how we bid a job. We know which Lakehills lots will need hydraulic rock breaking before the first shovel hits dirt. We know which ones sit inside the FEMA Special Flood Hazard Area and need an elevation certificate before a slab gets poured. That’s the difference between a contractor who has done this here and one who’s figuring it out on your lot.
Every contract includes our 90-Day Done Right Promise in writing. If something’s not right, one call brings Tom back. And every scope change, every allowance, every price adjustment arrives as a written change order before work proceeds. No surprises at the end. The permit inspector works for you, not for me, and that’s exactly how we like it.
Our Home Additions & ADU Services in Lakehills
ADU Design & Permitting
This is where Lakehills projects get complicated fast. A detached ADU on a Medina Lake shoreline lot can require permits from both FEMA and the Guadalupe-Blanco River Authority, plus Bandera County building permits. We handle the design, the elevation certificate, the shoreline easement variance, and the full permit package. Our Home Additions & ADU team has pulled these permits for Lakehills lots, and we know which drawings the county reviewer wants to see the first time.
Garage Conversion ADU
Converting an attached garage into an ADU in Lakehills runs $30,000-$80,000, but the real question is what your garage was built on. Many 1950s-1970s Lakehills cabins went up as seasonal fishing camps without engineered foundations. If your garage slab is a thin pour on uncompacted Hill Country soil, we may need to reinforce or replace it before framing interior walls. We’ll tell you that before you sign, not after demolition starts.
New Detached ADU
A new detached ADU in Lakehills runs $90,000-$220,000, and the spread comes down to site work. Limestone excavation for foundations and utility trenches adds $4,000-$9,000 on most Bandera County lots. If your lot sits inside the FEMA floodplain, your finished floor elevation has to sit at least 2 feet above base flood elevation, which can mean raising the entire structure. We price that in from day one, in writing.
Junior ADU & Interior Conversion
A junior ADU, built inside your existing home’s footprint, is usually the fastest and least expensive path in Lakehills. Because you’re not adding foundation or altering the roofline, the permit path is simpler, though shoreline and floodplain rules still apply to any new living space. For aging cabins off Park Road 37 and around the 78056 zip code, an interior conversion often avoids the rock-excavation cost entirely. It’s a smart first move for homeowners who want rental income or a place for aging parents without a full detached build.
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 Lakehills
We install products from manufacturers you can look up, not mystery brands off a van. For ADU and addition windows and doors in Lakehills, we regularly install Simonton and Ply Gem, and for impact-rated openings on lake-exposed lots, PGT. These are brands with published specs and real warranties. If your Lakehills addition calls for windows that can handle Hill Country sun and occasional wind-driven rain off Medina Lake, we’ll spec the right glass and frame the right way.
Common Home Additions & ADU Problems We See in Lakehills Homes
- Builder-grade cabin framing that fails inspection. Many 1950s-1970s Lakehills cabins were built as seasonal structures without load-bearing headers or proper subfloor anchoring. Adding a second story without a structural engineer’s sign-off leads to sagging floors and failed inspections. We bring the engineer in before we frame, not after.
- Skipping the FEMA elevation certificate before pouring an ADU slab. Medina Lake flood stages change quickly. A slab set 6 inches too low forces a costly tear-out or a variance your neighbors and the HOA will contest. We pull the elevation certificate first, every time.
- Under-budgeting for rock excavation. Hydraulic breaking of Bandera County limestone adds $4,000-$9,000 to every foundation or utility trench. A change order for that scope surprise can stall a draw schedule mid-project. We write that line into the original estimate so it’s never a surprise.
- Ignoring the dual shoreline constraint. Lakefront lots on Medina Lake can carry a FEMA Special Flood Hazard Area designation and a GBRA shoreline easement at the same time. The first sets your finished floor elevation; the second restricts how close your ADU can sit to the waterline. Builders from outside the county get caught on this constantly. We don’t.
Pricing for Home Additions & ADU in Lakehills, TX
Here’s the straight answer for Lakehills, because you should know the numbers before you call anyone:
| Project Type | Typical Range in Lakehills |
|---|---|
| ADU Construction (new detached) | $90,000-$220,000 |
| Garage Conversion ADU | $30,000-$80,000 |
| Home Addition (room addition) | $45,000-$130,000 |
What moves the number in Lakehills? Rock excavation, floodplain elevation requirements, and the condition of your existing foundation. A flat lot in the 78056 zip code with no FEMA designation will land on the lower end. A lake-view lot with 8 inches of topsoil over limestone and a GBRA shoreline easement will land higher. We give you a written, line-item estimate so you see exactly where every dollar goes. Call (877) 610-1318 for a free estimate, and ask about our free second opinion on any written estimate you’ve already received.
We Also Serve Cities Near Lakehills
Our Home Additions & ADU in Lakehills crew works throughout the Medina Lake area, including Helotes, Lackland Air Force Base, Leon Valley, and Fair Oaks Ranch. If you’re just outside the 78056 zip code, call us. Scheduling is coordinated from our San Antonio office, and we’ll tell you straight whether we’re the right fit for your lot before you commit to anything.
Serving Lakehills, TX - Our Local Coverage Area
We’re based in the Lakehills 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 Lakehills
Yes, if your lot sits inside the FEMA Special Flood Hazard Area, which includes many Medina Lake shoreline properties in the 78056 zip code. The elevation certificate establishes your base flood elevation, and your finished ADU floor must sit at least 2 feet above it. We pull the certificate as part of our ADU design and permitting package before any slab gets poured. Call (877) 610-1318 if you’re not sure whether your lot requires one.
Sometimes, but not always. Many 1960s Lakehills garages were poured as thin slabs without engineered footings or proper subfloor anchoring. If yours was, we’ll need to reinforce or repour before framing interior walls, which adds to the $30,000-$80,000 garage conversion range. We’ll inspect the slab and tell you the truth before you commit to anything. Estimates are free.
That depends on the Guadalupe-Blanco River Authority shoreline easement on your specific lot. The GBRA easement restricts how close any structure can sit to the waterline, and the setback varies by lot and subdivision. We pull the easement documentation during permitting and request a variance where one is available. On the Lakehills subdivision lot off Park Road 37 we mentioned earlier, we secured a variance for a 15-foot setback. Your lot may differ. Call (877) 610-1318 and we’ll look it up.
No. If you have a newer Lakehills home with an active builder warranty, hiring a separate contractor for an addition or ADU can void portions of that warranty, especially anything touching structural, electrical, or plumbing systems. We’ll review your warranty language before you sign and tell you exactly what’s at risk. Most Lakehills homeowners on newer builds wait until the structural warranty expires or work with one contractor for everything to keep the warranty intact.
Rock excavation and foundation work. Hydraulic breaking of Edwards Plateau limestone adds $4,000-$9,000 to foundation and utility trench work on most Lakehills lots, and on a second-story addition you’re also paying for structural reinforcement of the original cabin framing. Many 1950s-1970s cabins lack load-bearing headers, so the engineer’s retrofit happens before the second floor ever gets framed. We write that into the original estimate so it’s never a change-order shock. Call (877) 610-1318 for a free, written estimate.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Lakehills and the Medina Lake area with permits pulled and change orders in writing since 1998.