Home Additions & ADUs in Keller, TX

The reason to add on in Keller is almost always the same: a family has outgrown a house in a neighborhood — and a Keller ISD zone — they won't leave. Moving rarely pencils out against a settled school assignment, mature trees, and today's rates. The better question is how to add square footage that reads as if it were always there: a ground-level room addition, a second story, or an accessory suite. Which one fits comes down to your lot, your HOA, and how the addition ties into a house already resting on Keller's ground.

The impervious-surface rule that catches addition contractors

Keller has a submittal requirement that surprises crews from other cities. Every residential permit proposing an addition — or any improvement — has to itemize, right on the site plan, the individual square footage of all impervious surfaces on the lot: the main house's footprint, the addition, any accessory building, pools and pool decks, driveways, parking, and every walk and patio. It isn't busywork — the city tracks how much of the lot sheds water, and an addition that ignores it stalls at intake. We build that impervious tally into the plan from the start, not discovering it at the counter.

Build out or build up — your lot and soil decide

Building out is usually cheaper per foot, but it spends lot coverage and leans on your setbacks; building up preserves the yard. On Keller's split ground, that choice is structural too. A new slab on the sandy Cross Timbers loams west of downtown behaves differently than one on the Houston Black clay east and central, where the seasonal swing is severe. Either way, a ground-floor addition has to be engineered and doweled into your existing foundation so old and new move together, and a second story needs an engineer to confirm the current slab and framing can carry the load first.

The ADU question, answered honestly

If you're picturing a fully detached, rentable backyard cottage, hold that loosely for Keller — whether a detached ADU is allowed on your lot is a zoning question to confirm against current City of Keller code, not to assume. The reliably available paths are attached: a room addition, a second story, an in-law suite under the main roof with its own entrance, or a garage conversion. Keller's acreage tracts along Mount Gilead and Johnson Road give more room for a genuine accessory building — which still has to be itemized on that site plan.

One team owns the seam

An addition's whole promise is that it disappears into the house — matched brick, a married roofline, a foundation tie-in that holds. That's a coordination problem, not one trade's task. Permits run through City of Keller Building Services on the Tyler EnerGov portal that replaced the retired eTRAKiT, contractors must register first, and Building Services keeps a four-day week, closed Fridays. We're an Allen-based design-build serving Keller from about 40 miles east, not a local office, insured and bonded since 2019 — and we treat the join between old and new as the entire job.