Home Additions in Manor, TX: Costs & Process (2026)

What an addition costs in Manor

We price additions by the finished square foot, then adjust for what the specific house needs. These are the ranges we work in, and we convert them to one fixed number in writing before anybody swings a hammer.

Two numbers move a project the most: plumbing and foundation. A bedroom bump-out with no water in it sits at the bottom of the range. Add a bathroom, a wet bar or a laundry and you are running supply and drain lines, which pushes a job up fast. Same with a second story — the existing foundation and framing have to be evaluated by a licensed engineer before anyone can say what reinforcement is needed, and that engineering answer is what sets the price.

• Bump-out (80–200 sq ft, no plumbing): $45k–$90k — extending a kitchen, dining area or primary bedroom a few feet
• Single-room addition (300–500 sq ft): $110k–$200k — bedroom, office, game room or in-law suite on a new slab
• Addition with a full bath (400–700 sq ft): $150k–$280k — the bath alone adds roughly $35k–$60k of the total
• Second-story addition (600–1,200 sq ft): $350k–$600k+ — new stair, engineered reinforcement, full HVAC rework
• Engineering, survey and permitting: typically $4k–$12k, included in the fixed price, not billed later

What moves your number up or down

When we walk a Manor house, we are looking for the handful of conditions that decide where in the range you land. None of it is guesswork once we have the engineer's report and the plans.

• Foundation: a simple rectangular slab extension is the cheapest path. Pier-and-beam, stepped grades, or a design that cantilevers over an existing patio costs more.
• Plumbing runs: how far the new fixtures sit from the existing drain line. Thirty feet of new drain under slab is a different job than ten.
• HVAC capacity: most additions over about 300 sq ft need either a mini-split or a second system. Tying into an undersized existing unit is not a fix.
• Roof tie-in: matching a simple gable is straightforward. Weaving into a complex hip roof with multiple valleys adds framing and roofing labor.
• Finish level: builder-grade trim and stock doors versus custom millwork from our shop can swing a 400 sq ft addition by $20k–$30k.
• Exterior match: Hardie and brick on newer Manor subdivision homes are usually easy to source. Older masonry near downtown Manor may need hand-matching, which costs more.
• Electrical service: an addition can push an older panel past its capacity, and a service upgrade typically runs $3,500–$7,500.

What's particular about building an addition in Manor

Manor splits into two very different building problems. East and north of US 290 you have subdivision homes built mostly in the 2000s through the 2020s — slab-on-grade, engineered trusses, Hardie or brick veneer, tight side setbacks and a drainage plan the neighborhood was platted around. The framing is predictable and the materials are still in production, which keeps match-up costs down. What limits you is lot coverage and setbacks: on a lot like that, the buildable footprint is often smaller than homeowners expect, and a rear bump-out or a second story is the only direction with room. Most of those neighborhoods also have an HOA with an architectural review step, and that review runs on its own calendar — we submit it in parallel with permitting so it is not a surprise at week ten.

Closer to old downtown Manor the houses are older, smaller and more varied — pier-and-beam in places, additions already stacked on from previous decades, and exterior materials that are no longer made. Those jobs need more investigation before a price: we open up a small area, get a survey, and get an engineer out before we commit to a number.

The other constant out here is the soil. The Blackland Prairie clay east of Austin moves with moisture, which is why a new slab has to be designed by an engineer rather than copied from the existing house, and why we pay attention to how water leaves the site. Gutters, downspout extensions and finish grading around a new addition are not optional extras in this part of Travis County. Summer heat matters too — framing and roofing go up early in the day from June through September, and we size HVAC for the addition rather than hoping the existing system stretches.

Permits and inspections for a Manor address

Where your permit goes depends on your exact address, not on your mailing city. A Manor address can fall inside the Manor city limits, in unincorporated Travis County, or inside the City of Austin's extraterritorial jurisdiction — and the three paths have different submittal packages and different review queues. We confirm the jurisdiction from the plat and the address before we price the job, and we handle the submittal, the corrections and the inspection scheduling ourselves. You do not stand in line anywhere.

An addition permit package generally needs a current survey or site plan showing setbacks and lot coverage, architectural plans, an engineered foundation design, and energy-code documentation. Permit and review fees for an addition typically run $1,500–$5,000 depending on jurisdiction and square footage, and that figure is inside your fixed price. If the property is on septic rather than sewer, add a septic review — adding bedrooms or bathrooms can trigger a look at the existing system's capacity, and that review takes its own time.

Whether a wall can be modified, what reinforcement a second story needs, and what the plans have to show are decisions for a licensed engineer and the permit office — not for a contractor standing in your living room. We get those answers in writing during design so the construction price is built on facts. Inspections follow the normal sequence: foundation before pour, framing, rough-in for electrical, plumbing and mechanical, insulation, then final. We meet every inspector on site.

Realistic timeline, first visit to final inspection

Design and permitting happen before demolition, so the construction calendar we hand you is the one we build to. Here is how the weeks typically stack up for a single-room addition in Manor. A second story runs longer at nearly every stage, mostly in engineering and framing.

Total from first visit to final inspection: roughly 5 to 8 months for a room addition, 7 to 11 months for a second story. Review times are set by the permit office and the HOA, not by us, so we start that clock as early as possible and keep building the parts of the schedule we control.

• Weeks 1–2: site visit, measurements, scope conversation, preliminary range
• Weeks 2–6: design, survey, engineering, selections, fixed price in writing
• Weeks 6–16: permit submittal, HOA architectural review, corrections and approval
• Weeks 16–18: site prep, excavation, forming and foundation pour, cure time
• Weeks 18–24: framing, roof tie-in, windows and doors, dry-in
• Weeks 24–30: electrical, plumbing and HVAC rough-in, inspections, insulation, drywall
• Weeks 30–36: trim, cabinetry, paint, flooring, fixtures, exterior match, punch list and final inspection

How our fixed-price design-build process works

We design it, price it, permit it and build it — one contract, one crew, one number. Our carpenters are in-house, which is why the trim and cabinetry schedule does not slip while we wait on a sub to finish somewhere else.

You get a fixed price in writing before any work starts. That price includes design, engineering coordination, permit and review fees, materials at the specification you chose, labor, and cleanup. The only things that change it are changes you request in writing, or a genuinely hidden condition behind a wall we could not see before opening it up — and we tell you the number before we proceed, not after. Workmanship carries a 5-year warranty. Financing is available if you would rather not pull the whole project out of savings.

If you are collecting proposals in Manor, ask every contractor the same five questions. The answers separate a real scope from a placeholder number:

• Is this a fixed price or an estimate, and what specifically would change it?
• Who prepares the engineered foundation design, and is that cost inside the price?
• Which jurisdiction will this permit go through, and who submits and manages corrections?
• Is HOA architectural review included, and when does it get submitted?
• Are the carpenters employees or day-rate subs, and what does the workmanship warranty cover and for how long?

What to do next

Before you call anyone, pull together three things: your plat or survey if you have one, your HOA's architectural guidelines, and a rough square footage for what you want to add. With those in hand, a first conversation gets you a realistic range instead of a shrug.

From there we schedule a site visit in Manor, measure, talk through what the lot will allow, and give you a preliminary range the same week. If the range works, we move into design and engineering, and the fixed price follows once the plans are real. No start dates get promised until your permit is in hand.

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