Home additions, West Lake Hills, TX

Home additions in West Lake Hills: cover, trees and drainage

The city’s lot rules shape an addition more than the house does.

• Single-family lots of half an acre or more are capped at 25% impervious cover, like roof, slab and driveway. Smaller lots on city sewer can get a bonus.
• Removing trees or brush to make room needs a city permit first.
• Each building permit needs a drainage plan reviewed by the City Engineer. The city wrote its drainage rules after the 2015 floods, when new homes and additions were getting bigger.
• If the addition needs a variance, it goes to the Zoning and Planning Commission first, which adds about two to three months.
• The city runs its own septic permits, and some lots sit on the Edwards Aquifer recharge zone.

How we plan an addition in Westlake

First we add up the hard cover already on your lot and see how much room is left under the cap. Then we walk the lot for trees, because removing even brush needs a permit, and oaks cannot be trimmed from February through June. If the lot is tight, building up may fit where building out will not.

Our in-house design team draws the addition to match the house, with the drainage plan the city wants. You get an itemized quote, and the owner is on site managing the crew.

Home additions: the full service page

City of West Lake Hills pages and Census ACS 2024, as researched 2026-10-16. Rules change; we confirm them for your address.