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Texas · Climate zone 2–4

Custom House Plans in Katy, TX

Building requirements, permits and zoning in Katy, plus custom plans drawn to meet them. Customization is free and delivery starts at 24 hours.

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Where to get your Katy building permit

City of Katy Permit & Building Services

This office covers lots inside city limits. Many Katy addresses are outside them, so check your lot before applying. The city requires a certificate of occupancy before you move into a new home.

Checked November 2026. Offices and rules change, so confirm with the office before you apply.

House plans we draw in Katy, TX

Every plan is drawn from scratch for your lot in Katy, TX, with free customization and 30 days of revisions.

Building requirements

Building a house in Katy, TX: what the code requires

Statewide code, local enforcement varies

Building code
State law makes the IRC the residential code in cities. Counties have limited authority, so many unincorporated rural areas have no building permits or inspections.
Energy code
The IECC-based energy code applies in cities, and some cities (Austin) have stricter local codes.
Climate zone
IECC climate zone 2–4. Insulation, windows and HVAC are sized to match.
Typical frost depth
0–6 in (south), 12–24 in (north/Panhandle). Footings must extend below the local frost line (confirm with your building department).
Foundations
Raised or pier foundations where flood zones apply; slab inland.
Who can draw the plans
Single-family homes can generally be designed by a non-licensed home designer. A licensed engineer's stamp is often required for structural items, engineered foundations or special hazard zones, or when the local building official asks for it.
Engineer stamp
If your jurisdiction requires sealed drawings, add our Texas Engineer Stamp / Permit-Ready package ($1,000).

Texas-specific rules & hazards

Summary for planning only. Codes, editions and local amendments change, so always confirm current requirements with the building department that will issue your permit. Our designers check your jurisdiction before drawing.

Towns, villages & rural counties

Permit checklist for building in Katy and surrounding towns

Requirements differ town by town. Use this checklist with your local building, zoning and health departments, and include what you learn in your design instructions. We'll draw to it.

  1. 01Find who issues permitsIncorporated towns and cities usually have a building department. In unincorporated areas it's the county building or planning office, or a state agency, or in some rural areas nobody. Call before you buy the lot.
  2. 02Zoning & setbacksCheck the zoning district for minimum lot size, front, side and rear setbacks, maximum height, lot coverage and whether barndominiums, ADUs or metal buildings are allowed.
  3. 03HOA & deed restrictionsSubdivisions often restrict minimum square footage, exterior materials, roof pitch, garage orientation and outbuildings. These can be stricter than the town code.
  4. 04Septic & well permitsWithout city sewer or water, you'll need a percolation (perc) test and a septic permit from the county health department, plus a well permit.
  5. 05Driveway & culvert permitConnecting to a public road usually needs a driveway or culvert permit from the town, county or state DOT.
  6. 06Floodplain development permitIf any part of the lot is in a FEMA flood zone, you'll need a floodplain permit and an elevation certificate, and the lowest floor must be at or above the Base Flood Elevation plus any local freeboard.
  7. 07Energy code complianceMost jurisdictions require an energy compliance report (REScheck or similar) showing insulation, windows and HVAC meet the adopted energy code.
  8. 08Engineering stampMany building officials require a licensed engineer's seal for foundations, beams, trusses, or high wind, snow or seismic zones. Add our Engineer Stamp option at checkout.
  9. 09Utility & fire accessRural lots may need a fire-apparatus access road, a water supply for firefighting, or wildfire (WUI) defensible-space and ignition-resistant materials.
  10. 10Inspections scheduleA typical sequence is footing, foundation, framing, rough MEP, insulation and final. A certificate of occupancy is issued after final inspection.

Popular styles around Katy

Barndominium house exteriorFrom $1,300

Barndominium Plans in Texas

Metal-clad shell, soaring ceilings, a huge shop and very flexible interiors.

Modern Farmhouse house exteriorFrom $1,300

Modern Farmhouse Plans in Texas

Board-and-batten siding, black windows, metal roof accents and a deep front porch.

Mediterranean house exteriorFrom $1,595

Mediterranean Plans in Texas

Stucco walls, clay tile roofs, arches and shaded courtyards.

Katy and Texas house plan guides

House plans for sale around Katy

Katy building FAQ

Do I need a building permit to build a house in Katy?+

Yes. New homes in Katy require a building permit. Start with City of Katy Permit & Building Services. Expect to submit a full plan set, a site plan, energy compliance and, where required, sealed engineering.

What building code applies in Katy, TX?+

State law makes the IRC the residential code in cities. Counties have limited authority, so many unincorporated rural areas have no building permits or inspections. Check whether Katy has local amendments before you submit.

How much do custom house plans cost in Katy?+

Plans start at $1,050 for homes up to 1,000 sq ft and are priced by size, with free customization and 30 days of revisions. Engineer stamps for Texas start at $1,000.

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