Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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After
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AfterFast, Reliable Home Additions & ADU Across Manor
Home additions and ADU construction in Manor typically run $45,000 to $130,000 for a room addition and $90,000 to $220,000 for a detached ADU, with garage conversions landing between $30,000 and $80,000. Those numbers are anchored in what we actually see across Manor’s ShadowGlen, Whisper Valley, and other master-planned communities, where Blackland Prairie clay and builder warranty rules shape every scope of work. Barrett & Sons has been constructing in this exact part of the Austin metro since 1998, and we answer our own phone. Call (877) 610-1318 for a straight answer about your project.
Why Barrett & Sons Construction Is Manor’s Preferred Home Additions & ADU Company
Tom Barrett put his name on the truck in 1998, and his sons run the crews that work in Manor every week. Homeowners in 78653 call us because we handle the two things that make or break an addition here: the clay foundation work and the paper trail with the HOA and builder warranty office. Our Manor customers see the same faces on day one and final inspection. And when a change order is needed, it arrives in writing before the work happens, not as a surprise on the final bill.
We know Manor’s housing stock because we have walked it. Most homes were built between 2005 and today, slab-on-grade, wood-framed, and finished with builder-grade materials that start showing age around year five. That is not a knock on the home, it is just the math of high-volume construction. The foundation, drainage, and finish upgrades we handle in Manor follow patterns other contractors only read about. One call to (877) 610-1318 puts you in touch with someone who has seen your exact situation before.
- Owner-operated since 1998: Tom Barrett and his sons are on the job, not a rotating roster of subs.
- Written change orders, always: Price changes in Manor mean paper first, nail second.
- Permits pulled and inspections signed: No “permit optional” talk with HOA-governed subdivisions.
- 90-Day Done Right Promise: Written on every contract, honored with one phone call.
- A live person answers 24/7: Not a voicemail box, not an out-of-state call center.
Our Home Additions & ADU Services in Manor
ADU Design & Permitting
Most ADUs in Manor hit a wall at the design review phase, not the lumber stage. The Manor HOA boards and the architectural committees in communities like ShadowGlen and Whisper Valley require pre-approval on siding profile, window trim, exterior paint, and even roof pitch before a permit will be issued. Our Home Additions & ADU team prepares stamped drawings that anticipate those clauses, so your design passes review without three rounds of resubmission. We also submit stamped scopes to builder warranty administrators before load-bearing walls are touched, which protects what you already own.
Garage Conversion ADU
A garage conversion in Manor typically costs $30,000 to $80,000 and is the most cost-effective way to add a rentable unit or mother-in-law suite without adding foundation square footage. The catch in Manor is the HOA: many newer subdivisions require the architectural committee to sign off on the new window style, siding, and driveway layout before the permit application moves. We handle that pre-approval package as part of the scope. And because Manor sits on expansive clay, we always moisture-condition the existing slab edge and run a perimeter drain before the curb cut and utility trenching begin.
New Detached ADU
Standalone ADUs in Manor run $90,000 to $220,000, and the single biggest variable is the lot’s soil profile. Houston Black clay, which underlies most of Manor, has a swell potential above 30% in some horizons. A detached ADU needs a properly engineered post-tension slab or pier-and-beam foundation; skip that and you will see hairline cracks within two wet/dry seasons. We pull soil reports, set the subgrade with moisture conditioning, and install drainage that protects the ADU from the seasonal heave cycles that define Central Texas construction.
Junior ADU & Interior Conversion
Interior conversions, like a junior ADU carved from an existing primary suite or bonus room, are the most affordable path to an accessory unit in Manor. The work often falls under a different permitting class with the city and may trigger fewer HOA exterior review requirements, but it still must meet fire separation, egress, and utility isolation codes. We coordinate with Manor building officials and the HOA at the same time, so your conversion does not stall halfway through because the committee wanted a different window treatment while the city wanted a different smoke alarm layout.
ADU Site Prep & Utilities
Site prep in Manor is not a generic excavation. In Whisper Valley, off FM 973, the entire subdivision operates on a community-wide geothermal grid with buried ground-source heat pump loops and solar-ready conduit runs pre-installed on most lots. Trench wrong and you are into someone else’s loop field, which is an expensive fix and a failed inspection. Our crews pull the as-built utility drawings before we dig, and our Manor work coordinates around those buried loops the way other contractors simply cannot.
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 Manor
When you are spending six figures on a home addition or ADU in Manor, you should be able to look up every material that goes into it. We install named brands because they carry warranties you can actually enforce, and because a GAF roof or Schluter waterproofing system behaves the same way on the day we install it as it does ten years later. For Manor’s newer homes, we source materials that match existing builder-grade profiles so an addition does not look bolted on. Fast turnaround comes from local supplier relationships that keep trim, sheathing, and drain tile in stock inside the metro.
Common Home Additions & ADU Problems We See in Manor Homes
- Foundation heave under a new ADU slab. When the subgrade is not moisture-conditioned for Houston Black clay, cracks show within two wet/dry seasons. We have seen it repeatedly in Manor’s newest subdivisions, and it is always the same root cause.
- Voiding a builder’s structural warranty. Cutting into a load-bearing wall for a room addition without first submitting a stamped scope to the warranty administrator can void the warranty on the entire original home, not just the wall you touched.
- HOA design review rejection after work begins. Starting a garage conversion or exterior addition before the architectural committee approves the window trim, siding profile, and paint color is a fast way to get a stop-work order in Manor.
- Drainage failures that emerge after the addition is complete. Blackland Prairie clay sheds water differently than Hill Country limestone. A room addition that doesn’t include perimeter drainage and proper grade work will channel runoff against the slab joint and accelerate cracking.
Pricing for Home Additions & ADU in Manor, TX
Here are the real numbers we quote in Manor, based on current permit records, material costs, and the soil conditions we deal with every week:
| Project Type | Manor Price Range |
|---|---|
| Room Addition | $45,000 - $130,000 |
| Detached ADU Construction | $90,000 - $220,000 |
| Garage Conversion ADU | $30,000 - $80,000 |
What moves the number in Manor: the lot’s soil report, whether you are in a geothermal-grid subdivision like Whisper Valley, how much of the existing slab needs drainage correction, and what the HOA requires for exterior finishes. Foundation work is not an optional line item here, and homes built between 2005 and today often have builder-grade drainage that already needs upgrading before an addition ties in. Every allowance and every change order from us comes in writing before it costs you a dollar. Call (877) 610-1318 and we will send you a written estimate, not a verbal guess.
We Also Serve Cities Near Manor
Our crews run work all over the northeast side of the Austin metro. We serve Hornsby Bend, Pflugerville, Elgin, and Wells Branch with the same owner-operated crews, the same written change orders, and the same 90-Day Done Right Promise we bring to every job in Manor. If your project sits just outside the 78653 ZIP code boundary, call (877) 610-1318 and ask about a no-trip-charge estimate inside the county.
Serving Manor, TX - Our Local Coverage Area
We’re based in the Manor 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 Manor
Only if you cut into load-bearing framing without a stamped scope of work submitted to the warranty administrator before the saw touches the wall. We prepare the engineering package and submit it to the right office before the permit application goes in, so the conversion ties into your existing warranty instead of voiding it. Call (877) 610-1318 and we will walk you through the exact sequence for your builder.
You need a soil report and a foundation engineer’s review, not a contractor’s gut feeling. Houston Black clay’s swell potential means some Manor lots will handle a detached ADU on a post-tension slab and some will need pier-and-beam. We pull the soil boring and the report before we quote the foundation. Estimates are free; call (877) 610-1318.
Whisper Valley has a community-wide geothermal grid with buried ground-source loop fields and pre-run solar conduit on most lots. Any utility trench for an ADU has to coordinate around those loops using the subdivision’s as-built drawings, a constraint that does not exist in neighboring Manor or Pflugerville subdivisions. We pull those drawings before we dig on every Whisper Valley lot.
You should not. Interior conversions that require permits are city-regulated, and starting before HOA approval is issued can trigger a stop-work order and a failed inspection if the committee decision changes your egress window or utility routing. We sequence the architectural review ahead of the city permit so both are clean before we start. For a straight answer on your specific Manor HOA, call (877) 610-1318.
On Manor’s Blackland Prairie clay, we typically advise homeowners to reserve 10-15% of the total addition budget above the framing number for foundation and drainage work when adding a second story to a 2000s-era slab-on-grade home. The existing slab may need perimeter drainage, moisture conditioning, or localized repair before it takes the added load. We quote the soil and foundation work separately and in writing, so you know that number before you sign.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Manor and the surrounding metro since 1998.