i30 Builders · Residential
ADU and Casita Builder in Rockwall and DFW
A guest house, casita or backyard suite, designed for your lot and your city's rules, then built from the foundation to the final inspection.
Written scope and locked price before any deposit. One-year workmanship warranty.
Get a written estimate
Four fields. We call back within one business day to set up the site visit.
- GL + umbrella coverage
- $1M + $1M
- Workmanship warranty
- 1-yr
- Cities served
- 33
Who builds ADUs and casitas in Dallas-Fort Worth?
i30 Builders, a general contractor based in Royse City, TX, designs and builds ADUs, casitas and guest houses across Rockwall and DFW for homeowners across Dallas-Fort Worth, centered on Rockwall, Collin, Hunt and Kaufman counties. Zoning and HOA rules checked for the address, then design, engineering, permits, foundation, framing, utilities, finishes and final inspection, priced in writing on the plan set and built in phases. Every job is measured and designed for the house, then priced in writing after a site walk, before any deposit, with permits handled.
- Pricing
- Written price after a site walk, before any deposit
- Permits
- Handled by us
- Warranty
- One-year workmanship warranty, in writing
- Where
- Dallas-Fort Worth, centered on Rockwall, Collin, Hunt and Kaufman counties
Updated
Start Here
What you can build in the backyard is decided at city hall first.
Every city around here treats a second living space on a single-family lot its own way. One calls it guest quarters, another an accessory dwelling, and some only allow it by special permit. The city and the HOA set the size cap, whether it can have a kitchen, how many accessory buildings the lot can hold, how far it sits from the property line and whether it can be rented. Those rules shape the building before any style choice does, so we read them for your address first.
Then the utilities. A casita needs power and water, a sewer line, and often gas, all run from the house across the yard. The sewer has to fall the whole way to the main, so the distance and the depth of the house drain decide where the building can sit. The panel has to carry a second building. On expansive clay, the foundation is designed for the soil, not copied from the house.
We build these design to final: drawings and engineering, permits, foundation, framing and dry-in, the systems, the finishes and the final inspection, one phase at a time. That is how the ADU we are building in Tyler is running now. A storage shed with drywall inside is not an ADU, and not work we take.
How the planning works
Measured, drawn and picked before anything comes out.
Step 1
Zoning and HOA for your address
What your city calls the building, the size and height caps, whether a kitchen is allowed, the setbacks, the accessory building count and any rental rule. Plus your HOA's restrictions. This decides whether the project makes sense before you pay for drawings.
Step 2
Site and utilities
Where the building can sit given the setbacks, the trees, the drainage, and the route for sewer, water, power and gas from the house. We check the sewer depth and the panel capacity on the walk.
Step 3
Design and engineering
Floor plan, elevations matched to the house, a foundation designed for the soil, and framing and roof engineered where the city asks. Selections are made while the drawings are still open.
Step 4
Written scope, phased build
One price in writing on the plan set, broken into phases from permits and foundation through framing, systems, finishes and final. Each phase is billed as it starts.
Finish levels
Mid-grade or high-end, named by what goes in.
Most rooms mix the two. Tell us where you want to spend and where you do not, and the written scope names every material either way.
Mid-grade
- Post-tensioned or engineered slab foundation designed for the soil
- Wood framing, fiber cement siding and a shingle roof matched to the house
- One bath with a tiled shower, and a kitchenette where the city allows one
- Ductless mini-split cooling and heating
- LVP flooring, painted drywall, standard trim
High-end
- Brick or stone matched to the main house, standing seam or matching roof
- A full kitchen where zoning allows, with cabinetry built to the room
- A curbless tiled shower and a separate laundry closet
- Ducted or multi-zone cooling, spray foam insulation
- A covered porch, vaulted ceilings and its own electrical subpanel
Some cities do not allow a full kitchen in guest quarters. We confirm that before the layout is drawn.
Code and permits
The rules that apply to this room.
- Rockwall defines guest quarters as an accessory building for the temporary occupancy of guests of the main house. It has to stay ancillary to a single-family home, cannot exceed 30 percent of the primary structure's square footage, and cannot be sold or conveyed separately. City of Rockwall, Case Z2025-004 staff report (Unified Development Code)
- Under the same Rockwall standards, guest quarters may not include kitchen facilities such as a stove, an oven or a food preparation area. City of Rockwall, Case Z2025-004 staff report (Unified Development Code)
- Rockwall allows two accessory structures on a single-family lot unless its table says otherwise, and anything over the size limits needs a Specific Use Permit. City of Rockwall, accessory building permit requirements (UDC Subsection 7.04)
- Rockwall requires accessory structures to be architecturally compatible with the main house and to sit behind its front facade, and does not allow two-story accessory buildings. City of Rockwall, accessory building permit requirements (UDC Subsection 7.04)
- Rockwall has approved guest quarters on an SF-7 single-family lot by Specific Use Permit ordinance, with the footprint, total size and height capped in the ordinance itself. City of Rockwall, Ordinance No. 22-13 (SUP S-272)
Read from the model codes on the dates linked. Each city adopts its own edition with its own amendments, so we confirm the rules for your address before we pull the permit.
Ready to get yours planned?
A free site walk, then a written scope and one price within five business days.
In every job
- Zoning, setbacks and HOA rules checked for your address before design
- Drawings and engineering for the foundation and framing
- Sewer, water, power and gas run from the house and inspected
- Foundation, framing, roof, windows and exterior matched to the house
- Insulation, drywall, finishes, and heating and cooling sized to the building
- Permit and inspections through final, the punch list before final payment, and a one-year workmanship warranty
How we quote it
We do not publish prices or ranges. Every job is measured and built for your house, so a number off a website would be a guess.
A site walk, then a written scope back within five business days. The scope names the work, the materials and the price, and the price does not move unless the scope does.
Anything found behind a wall or under a slab that changes the work gets priced and approved before we touch it. That is a change of work, in writing, not a surprise on the final invoice.
Payment is by ACH, card, check or cash, on the schedule written into the contract.
What Moves the Number
Up and down, before you ask for a quote.
Pushes price up
- Distance from the house, which lengthens every utility run
- A full kitchen and a full bath
- A sewer line that cannot fall by gravity and needs a pump
- A panel upgrade to carry a second building
- Soil that calls for a heavier foundation design
- Masonry, roof and window details matched to an older house
Keeps price down
- Siting close to the house, the sewer line and the gas
- A studio layout with one bath
- A simple gable roof and fiber cement siding
- A panel with room for the new load
- Finishes picked while the plans are still being drawn
Common Questions
ADUs and Casitas questions, answered
Are ADUs allowed in Dallas-Fort Worth cities?
It depends on the city, the zoning district and the HOA. In Rockwall, for example, guest quarters have to stay ancillary to the house, cannot exceed 30 percent of the main house's square footage, cannot be sold separately and cannot have kitchen facilities, and the city has approved one on an SF-7 lot through a Specific Use Permit. Other cities draw the lines elsewhere. We check yours before you pay for drawings.
What is the difference between an ADU, a casita and a guest house?
In conversation, not much. All three mean a second, smaller living space on a single-family lot, detached or attached. To a city the difference is what is inside: a kitchen, a full bath, a separate entrance, a separate meter. Those are what move a building from guest quarters to a second dwelling in the code, so the floor plan follows the zoning.
Can I rent out an ADU?
That is a zoning question, and the answer changes by city and by HOA. Some cities treat guest quarters as space for guests of the main house only, and some deed restrictions bar renting any part of the lot. Tell us at the start if rental income is the plan, because it decides whether the project works on your lot.
Can you turn a detached garage or workshop into a casita?
Often. The building is there, but it was not built to be lived in: the slab needs checking for moisture, the walls and roof need insulation, and water, sewer and cooling have to reach it. The zoning still applies, because the city sees a new living space either way. We scope it like a new build where the shell is already paid for.
How do utilities get to a backyard ADU?
In trenches from the house. The sewer line is the one that decides placement, because it has to fall all the way to the main. Power comes from the house panel or a new service, depending on the load and the utility. Water and gas branch off the house lines. Whether you can have separate meters depends on the city and the utility, and some do not allow a second water meter.
Does a backyard ADU need its own foundation design?
Yes. North Texas clay swells when wet and shrinks when dry, and a small building sitting on it moves unless the foundation is designed for it. We have the slab engineered for the soil on your lot, and we grade the site so water runs away from the new building and the house.
How long does it take to build an ADU?
Two clocks. Design, zoning and permits usually take 2 to 4 months, longer if the city needs a special permit with public hearings. The build itself usually runs 4 to 8 months, driven by the foundation, the utility runs, inspections and the finishes you pick. You get the phase schedule in writing before we start.
How is an ADU priced?
On the plan set, in writing, broken into phases so you see what each part of the building costs. Distance from the house, the kitchen and bath, the foundation design and the exterior match move it most. The price does not move unless the scope does.
Prefer to give us the details now?
Tell us what you want built and roughly how big. We walk it, then price the scope in writing, and the price does not move unless the scope does.
indicates a required field
Step 1 of 2: Project info