Fast, Reliable New Detached ADU Across Irving
If you’re searching for a New Detached ADU in Irving, TX, the realistic all-in cost for a custom 1-bedroom unit runs $190,000-$310,000, with modular and prefab builds landing between $150,000 and $260,000 depending on site conditions, pier depth, and whether county floodplain or septic review applies. That’s a written price before we start, per Haven Standard Clause 1, not an estimate that drifts upward mid-project. Ellery ADU Studio designs, permits, and builds detached accessory dwellings across Irving under one contract at one written price, so the drawings, the permit set, and the construction are never split between a designer who blames the builder and a builder who blames the designer. Call (971) 497-2402 and a live person answers, 24/7, not a voicemail queue.
Why Ellery ADU Studio Is Irving’s Preferred New Detached ADU Company
We’ve built detached accessory dwellings in Las Colinas, Valley Ranch, Hackberry Creek, and the Heritage District, and we’ve learned that Irving projects fail in predictable ways when the builder doesn’t understand the gap between what the market wants and what the city is actually set up to approve. Irving anchors the Las Colinas corporate corridor, and the demand for workforce and short-term-rental ADUs from airline, hospitality, and corporate employees is unusually concentrated for a Metroplex city of this size. Yet Irving’s zoning department has been more conservative on accessory dwellings than most of its neighbors, and the municipal permitting infrastructure is visibly catching up to demand. That mismatch means a builder who files a permit set without anticipating county-level floodplain, septic, or well setbacks will lose months. We plan for that before we price the job.
Nadia Ellery founded this studio in 2015 on a simple observation: a permit set is not paperwork, it’s the product. Every Irving project we run gets a documented photo record on every visit, a written scope locked at signing under Haven Standard Clause 5, and a 365-Day Done Right Promise in writing: if the finished ADU is not built to the permitted drawings, we make it right. Our crews are background-checked and uniformed, and our license number appears on every page we hand you. No designer-versus-builder blame gap. One contract, one name on the permit, one written number.
Our New Detached ADU Services in Irving
Custom Built ADU
A custom detached ADU in Irving means a stick-built unit designed around your specific lot: the shape of the drain field, the depth of the engineered piers, the setback from the property line on an acreage parcel. On a standard 7,000-9,000 sq ft Irving lot in the Heritage District or an older Valley Ranch section, that typically means a 400-800 sq ft unit with its own sewer tap or a connection to an existing lateral that’s been scoped and verified. On a half-acre or larger lot, we’re often working with Dallas County on septic and floodplain review in parallel with City of Irving zoning. A custom 1-bed or 2-bed in Irving generally runs $190,000-$310,000 all-in, drawings through final inspection.
Prefab ADU Installation
Prefab works in Irving when access works. A factory-built unit from a brand like Abodu or Dvele arrives as a module or panelized shell, which means we need a crane, a staging area, and a delivery route that can handle a wide-load truck. On older Irving streets with mature trees and narrow alleys, that’s not always a given, and we’ll tell you before you spend a dollar on design. Prefab in Irving typically lands between $150,000 and $240,000 complete, including the foundation, utility connections, and the finish work that happens on site.
Modular ADU
Modular construction in Irving splits the difference: the unit is built to local code in a controlled factory, then set and finished on your slab. Our crew built a 1-bedroom modular ADU on a half-acre lot in Hackberry Creek where the septic setback forced the unit 20 feet from the property line. We coordinated the septic permit with Dallas County, engineered piers to 12 feet through the expansive black clay, and brought in a Dvele modular shell with a crane because the narrow access road couldn’t handle a full prefab. That unit cleared county floodplain review in six weeks. A modular ADU in Irving typically runs $160,000-$270,000, and the price holds because the scope is locked in writing before the factory starts cutting.
Studio ADU
A studio ADU in Irving is the most common request we see from homeowners near DFW Airport and the Las Colinas corridor: a 350-500 sq ft unit with a bathroom, a kitchenette, independent HVAC, and a separate entrance. These are workforce housing units for airline crews, corporate relocations, and short-term rental operators. On a standard Irving lot, a studio ADU typically runs $150,000-$210,000. On acreage near the Elm Fork of the Trinity River, add the cost of an elevation certificate and floodplain development review before framing can start.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Irving
We specify and coordinate prefab and modular systems from Abodu, Cover, Dvele, and others, including James Hardie siding where a hard-wearing exterior matters. When we quote a prefab or modular ADU in Irving, we’re not reselling a kit; we’re writing one contract that includes the factory unit, the foundation, the utilities, the site work, and the finish trades. If the module arrives and something is off, there’s no phone tree between a manufacturer and a site crew. It’s our name on the permit and our written price on the line.
Common New Detached ADU Problems We See in Irving Homes
- Sewer laterals and drain fields that were never scoped before design. Irving’s 1960s-1980s tract homes on concrete slabs often still have cast-iron or early-PVC laterals. We scope the line and run a perc test before we draw a single wall, because discovering a drain field under the only buildable corner of your lot after design is a six-figure mistake.
- Foundation piers that were guessed, not engineered. Irving sits on North Texas expansive black clay that shrinks hard in summer drought and heaves after rain. A detached ADU slab on this soil needs engineered pier depths of 10-12 feet. A builder who pours a shallow slab is handing you a cracked foundation by fall.
- Floodplain review that started too late. Significant stretches of older Irving near the Elm Fork of the Trinity and its drainage tributaries fall within FEMA Special Flood Hazard Areas. You’ll need an elevation certificate and floodplain development review before a building permit issues, and starting that after design can add months. We start it in week one.
- Electrical panels with no room for a second unit. Most older Irving homes have 100-amp panels. An ADU with its own HVAC, kitchen, and laundry almost always needs an upgrade to 200 amps, and that cost belongs in the written price from day one, not as a surprise change order in month four.
Pricing for New Detached ADU in Irving, TX
| ADU Type | Typical All-In Range in Irving |
|---|---|
| Studio ADU (350-500 sq ft) | $150,000 - $210,000 |
| 1-Bed ADU (500-750 sq ft) | $190,000 - $285,000 |
| 2-Bed ADU (750-1,000 sq ft) | $240,000 - $310,000 |
| Prefab / Modular ADU (any size) | $150,000 - $270,000 |
These ranges are all-in: drawings, permit set, site work, foundation, utilities, finishes, and final inspection. What moves the number in Irving: engineered pier depth on expansive clay, whether your lot falls in a FEMA flood zone, septic and well setbacks on acreage, the condition of your existing sewer lateral, electrical panel capacity, and whether a crane can reach the build site. Every quote from us is a written fixed price before any work begins, per Haven Standard Clause 1. If you already have a written estimate from another builder, bring it in and we’ll give you a free second opinion. Call (971) 497-2402 to schedule yours.
We Also Serve Cities Near Irving
Our Irving crews work across the Metroplex. We build detached ADUs in Dallas, Mesquite, Lancaster, and Duncanville, and we serve homeowners throughout the region from our Dallas-Fort Worth office. If you’re looking for a New Detached ADU in Irving or anywhere in the surrounding area, the same written-price guarantee and one-contract model applies.
Serving Irving, TX - Our Local Coverage Area
We’re based in the Irving 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 - New Detached ADU in Irving
A detached ADU on a half-acre or larger Irving lot typically triggers county-level review in addition to City of Irving zoning: Dallas County septic permits if you’re not on city sewer, well setbacks if you have a private well, and floodplain development review if any part of the property touches a FEMA Special Flood Hazard Area, which is common near the Elm Fork of the Trinity. We start all three of those applications in parallel with the city permit, because running them sequentially can add two to four months to the timeline. Call (971) 497-2402 for a written scope that includes every permit line item.
In Irving’s expansive black clay, an engineered pier foundation for a detached ADU typically needs to go 10-12 feet deep, drilled to a depth that reaches stable moisture content below the active shrink-swell zone. A standard shallow slab that would pass in other Texas cities will heave and crack here within the first year. We hire a geotechnical engineer on every Irving ADU, and the pier depth is in the written price before we start. Call (971) 497-2402 to see what your specific soil report says.
You’ll need an elevation certificate from a licensed surveyor and a floodplain development review through the county before the City of Irving will issue a building permit for a detached ADU in a FEMA Special Flood Hazard Area. Depending on the flood zone, the finished floor elevation may need to be raised, which changes the foundation design and the access stairs. We pull that certificate in the first week of the project so it never becomes a last-minute delay. Call (971) 497-2402 for a written quote that includes flood review.
Usually, yes, but access determines the method. On a tight Irving lot with a narrow driveway, we may bring a modular unit like Dvele or Abodu in sections with a smaller crane, or we may switch to panelized construction that assembles on site. Our Hackberry Creek project used a crane because the only street access couldn’t accommodate a full wide-load prefab, and the unit cleared floodplain review in six weeks. Call (971) 497-2402 and we’ll walk the lot before we recommend a system.
It needs independent HVAC. Irving summers regularly push past 100°F, and your main home’s unit almost never has surplus capacity to condition a second dwelling. We size a dedicated system for the ADU based on its own square footage, orientation, and window load, and that line item is in the written price. Sharing ductwork with the main house is a code problem and a comfort failure in a Texas summer. Call (971) 497-2402 to get a written quote with the HVAC specified, not guessed.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Irving since 2015.