Casitas in North Texas: The Backyard Guest House Guide

Casita, ADU, guest house — the same thing

Casita is the regional term, borrowed from Spanish-influenced Southwestern architecture and now used across Texas for a detached secondary dwelling. Functionally it is an accessory dwelling unit. If it contains a kitchen and functions independently, your city will regulate it as an ADU regardless of what you call it.

The word matters less than the kitchen. A detached guest suite with a wet bar is usually treated as an accessory structure. Add a range and it becomes a second dwelling unit, with the zoning consequences that follow.

What one costs

A casita costs more per square foot than an attached addition because it is a complete small house: its own foundation, roof, exterior envelope, HVAC system, and utility runs from the main house or the street.

Answer these five questions before designing anything

In order, because each one can end the project:

1. Does the HOA allow a second dwelling? In much of North Texas the deed restrictions are stricter than the city code. Cheapest thing to check, so check it first.
2. Does zoning permit an ADU on this lot? Minimum lot size, allowed districts, and whether a special use permit is required all vary by city.
3. What is the maximum size and where can it sit? Setbacks, height limits, and lot coverage determine the buildable envelope.
4. Can utilities reach it? Water, sewer, gas, and electrical — and does the existing panel and sewer line have capacity for a second dwelling?
5. Can it be rented? Some cities allow long-term but restrict short-term rental; some require owner occupancy of one unit.

Design notes that matter

A casita reads well when it looks like a smaller sibling of the main house — same roof pitch, same materials, same window proportions. When it looks like a shed with windows, it hurts the property rather than helping it.

Inside, build for flexibility. A casita serves as a guest house, an in-law suite, an office, a studio, and sometimes a rental over a house’s life. A full bathroom, a kitchenette that could become a kitchen, its own HVAC zone, and decent sound separation from the main house keep it useful when the reason changes.

And design the path between the two buildings — a covered walkway or a considered courtyard makes the casita feel like part of the property rather than a building parked in the yard.

See our ADU rules and costs guide and multi-generational remodeling page.