







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Grapevine, TX
Fielding ADU Builders handles ADU construction, garage conversions, and room additions in Grapevine, TX. This city has a specific wrinkle most Metroplex towns don’t: a Historic District with design review, plus a granny flat ordinance that limits ADUs to lots of 7,200 square feet or larger with rear yard setbacks. That means the work here starts with a lot survey and a permit conversation, not a sketch on a napkin. If you’re weighing a backyard unit or a garage conversion in Grapevine, call (903) 342-8977 and we’ll walk you through what your specific lot allows.
Why Grapevine Homes Are Different

Grapevine’s housing stock splits into two distinct worlds. North of Highway 114, you’ll find 1970s-to-1990s ranch homes and traditional brick builds on larger lots: these are the parcels where the granny flat ordinance actually works, because the lot meets the 7,200-square-foot minimum and there’s room for the rear setback. The older central neighborhoods are a different job entirely: Craftsman and Victorian homes from the early 1900s, many under historic preservation rules that can dictate matching brick, board-and-batten siding, and rooflines before a single drawing gets approved.
Climate matters here too. Grapevine sits near Grapevine Lake, which means higher humidity than other parts of the Metroplex and occasional drainage headaches. Any ADU or addition we build in Grapevine gets HVAC sized for the humidity, not just the heat. We also check the flood map early: some lakeside parcels need elevated foundations or flood-resistant materials, and that changes the structural plan before we ever submit for permits.
Reed Calloway runs Fielding ADU Builders. He came up through the Garrison Partners network, which has been building to The Garrison Standard since 2006. That standard means a written price before work starts, permits pulled by the book, and a 365-Day Done Right Promise in writing. In Grapevine, where the permitting desk can reject a plan for the wrong siding profile, that discipline is the difference between a project that starts on time and one that dies in review.
Our Main Grapevine Services
Grapevine homeowners call us for three jobs more than anything else: converting an attached garage, adding a room to a 1970s or 80s ranch, and building a backyard ADU on a lot that clears the city’s 7,200-square-foot rule. Each has its own page here with pricing and specifics.
Room Addition Contractor in Grapevine
A room addition in Grapevine often means bumping out a ranch home’s footprint or adding a second-story suite, which means matching existing brick lines and rooflines so the finished addition doesn’t look stapled on. The city’s design review process gets easier when the addition reads as original construction, and our crews have done enough Grapevine work to plan for that from the first framing walk. We use conventional framing with James Hardie siding where the elevation calls for it, and every addition gets a written price before any work starts. Room Addition Contractor in Grapevine.

Garage Conversion Contractor in Grapevine
Grapevine’s 1970s and 80s subdivisions are full of attached two-car garages that stopped being worth parking in. A garage conversion here usually means insulating the slab, running HVAC from the main trunk, and matching the exterior so the conversion reads as original square footage. We handle the permit submittal, the flood-plain check, and the final inspection. If the conversion fails inside a year, the Garrison Standard sends us back at no charge. Garage Conversion Contractor in Grapevine.

ADU Builders in Grapevine
A backyard ADU in Grapevine has to clear the city’s granny flat ordinance first: a 7,200-square-foot minimum lot, rear yard setbacks, and often a design compatibility review. We work with prefab platforms like Plant Prefab and Abodu when the lot and budget favor a factory build, and we also build conventional ADUs with James Hardie siding. Either way, you get the same written price guarantee and the same one-year Done Right Promise. ADU Builders in Grapevine.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Grapevine
We build with Plant Prefab and Abodu for modular ADUs, Tuff Shed for accessory structures, and James Hardie siding on conventional builds of every kind. Each brand has a known lead time and a known cost per square foot, so we can quote a real number without back-and-forth. See our brands for the full list.
Pricing for ADU Company in Grapevine, TX
| Service | Typical range in Grapevine |
|---|---|
| Prefab ADU (single-unit, standard foundation) | $120,000 – $270,000 |
| Conventional ADU (custom build) | $180,000 – $340,000 |
| Garage conversion (attached, finished to code) | $45,000 – $90,000 |
| Room addition (ground-floor bump-out) | $90,000 – $180,000 |
| Room addition (second-story suite) | $140,000 – $250,000 |
| Historic District ADU (design review compliance) | Adds $15,000 – $30,000 |
| Flood-plain foundation upgrade | Adds $10,000 – $25,000 |
| Permit fees (city and county) | Typically $3,000 – $8,000 |
What pushes a Grapevine ADU to the top of that range is usually lot work: a rear setback variance, a flood-plain elevation change, or a Historic District compatibility review. What doesn’t change is our price: the number in our written proposal is the number on the final invoice, no change orders disguised as surprises. That’s the Garrison Code: price in writing, by the book, leave it clean, stand behind it for a year.
Neighborhoods We Serve in Grapevine

We work across Grapevine’s residential map every week. We know which neighborhoods north of Highway 114 clear the city’s lot-size rule without a variance, and which central streets need a design review conversation before we even draw.
- Historic District
- Heritage
- Shady Lane
- Timberline
- Oak Creek
Scheduling in Grapevine typically runs two to four weeks out for an initial site visit, and we can usually be on-site within a week of permit approval. Dispatch and scheduling are coordinated from the brand’s Dallas-Fort Worth office; crews serve Grapevine locally.
Service Area – Cities Near Grapevine
We also handle ADUs, garage conversions, and room additions in the cities around Grapevine, including Coppell, TX, Carrollton, TX, Dallas, TX, and Irving, TX. If you’re just over the Grapevine line, we can still quote your job with the same written-price promise.
Serving Grapevine, TX - Our Local Coverage Area
We’re based in the Grapevine area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU Company in Grapevine

Most Grapevine ADU permits clear in 6 to 12 weeks, depending on whether the lot needs a variance or a Historic District compatibility review. A lot that clears the 7,200-square-foot minimum and rear setback without a variance usually moves faster. Call (903) 342-8977 and we’ll check your parcel before you commit.
We handle the city permit submittal, the inspection schedule, and the paperwork. If your HOA has an architectural review committee, we prepare the submittal package they’ll ask for: drawings, materials list, and a written scope. HOAs can add time, but they don’t change our price.
No. The price is in writing before any work begins, and that’s the number on the final invoice. The only exception is if you change the scope after signing: change the roofline, add square footage, or switch materials. Otherwise, the number holds. Call (903) 342-8977 for a free estimate.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Grapevine Customers Say
"Clear price breakdown. Change orders were all in writing."
- Hal P."Good addition. Electrical inspection delayed a week, which was the county, but the build is great."
- Eva K."Garage conversion with a new bath and kitchenette. Permit was handled by them. Inspection passed first time."
- Sheila B.





