Home additions · Williamson County, TX

More room — without moving.

Whether it's a bedroom, an in-law suite, or a second story, we design additions that match your home inside and out — with an honest estimate up front and craftsmanship backed for life.

  • Lifetime craftsmanship warranty
  • Estimate Guarantee — no surprise costs
  • Blends with your home — structure to shingles
After — addition exterior, matched roofline
After
Before — exterior, same angle as after
Before
FLENN CUSTOM HOMESCENTRAL TEXASLIFETIMECRAFTSMANSHIP WARRANTY

Our promise

Backed for life

“We provide a lifetime guarantee on the quality of our craftsmanship. If any issues arise related to the work we perform, we will address them promptly and professionally.”

FLENN CUSTOM HOMESCENTRAL TEXASESTIMATENO-SURPRISE PRICING
Estimate GuaranteeHonest numbers up front. The price you contractually agree to is the price you pay — barring changes you request.
FLENN CUSTOM HOMESCENTRAL TEXASON-TIMEWE SHOW UP AS PROMISED
On-Time GuaranteeA clear schedule and a crew that shows up when we say we will — from foundation to final inspection.
FLENN CUSTOM HOMESCENTRAL TEXASLIFETIMECRAFTSMANSHIP WARRANTY

What's included

Additions that belong

Rooflines, siding, trim, and proportions matched — inside and out — so the addition looks like it was always part of your house.

  • Bedroom & bathroom additions

    The extra room your family needs, built to match the rooms you already have.

  • In-law suites & multigenerational spaces

    Private entrance, kitchenette, accessible bath — parents close, everyone with their own space.

  • ADUs & guest houses

    A separate space on your lot — for family today, or rental income tomorrow.

  • Second-story additions

    Go up instead of out — structural engineering handled in-house.

  • Sunrooms & living-space extensions

    More light and more room in the spaces where you already live.

  • Garage conversions

    Turn unused square footage into an office, gym, or guest room.

Our work

Additions that look like they were always there

Matched rooflines, siding, and trim — see if you can spot where the original house ends.

  • In-law suite addition — Hutto
  • Family room addition — Cedar Park
  • Living-space extension — Pflugerville
  • Second story — Round Rock
  • Garage conversion — Georgetown
  • Sunroom — Leander
Addition / value build — Hutto, after
In-law suite addition — Hutto

How we work

Honest from the first estimate

Design, engineering, and Williamson County permitting in one plan — no hand-offs between an architect, an engineer, and a builder.

  1. 01

    Tell us about the space you need

    The form takes two minutes. Greg or Pam calls you back within one business day.

  2. 02

    Walk your home with Greg

    He listens to what you need, then gives you an honest read on the best way to add it.

  3. 03

    One clear plan

    Design, engineering, and permits in one written estimate and one schedule — no hand-offs.

  4. 04

    Built right, backed for life

    An addition that blends structure to shingles — with a lifetime warranty on the craftsmanship.

Neighbors, not clients

95% of our work comes from referrals

27+ Years of experience
~75 Homes & remodels
95% Referral-driven
“Took my dream home and made it a reality… made the process simple and easy.”
Austin Llana Custom project client Google Review
“The level of craftsmanship and attention to detail they bring to every aspect of the project is truly impressive.”
Casey & Tim Gibbs Remodeling clients Google Review
“He always answered calls, text or emails promptly and guided us through the project.”
Cindee Molenda Repeat client — two projects over 15 years Google Review

Request an estimate

Tell us about the space you need

Two minutes, no pressure. Greg or Pam will call you back within one business day.

  • No obligation — an honest read either way
  • Your info stays with us
  • A real person calls you — no call centers
Estimate Guarantee Lifetime Warranty
Prefer to talk? Call (512) 677-3992

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Straight answers

Questions homeowners ask us

If yours isn't here, ask — you'll get the honest answer either way.

Will the addition match our existing house?

That's the whole job. We match rooflines, siding, trim, and proportions — inside and out — so it reads as original, not added on.

Do we need a permit for an addition in Williamson County?

Almost always, yes. We handle permitting, engineering, and inspections end to end — it's built into the plan and the schedule.

How long does an addition take?

A single room is quicker than an in-law suite; a second story takes the longest. You'll get a written schedule with your estimate — and our On-Time Guarantee means we keep it.

Can we live at home during construction?

Usually, yes. Additions build from the outside in, and we schedule the breakthrough days with you in advance.

Is an addition worth it versus moving?

If you love where you live, usually yes — you skip selling costs and keep your schools, neighbors, and equity. If moving actually pencils better for you, Greg will say so. That's the point of an honest estimate.

Can you build an in-law suite or ADU?

Yes — it's one of the fastest-growing things we build: aging parents, adult kids, and rental income all drive it. Private entrances, kitchenettes, and accessible baths included.

Where we build

A local builder for local homes

Family-run from Georgetown — Greg is on your job site, not in an office.

  • Georgetown
  • Round Rock
  • Cedar Park
  • Leander
  • Liberty Hill
  • Hutto
  • Pflugerville
  • Taylor
  • Austin