Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Highland Park
A home addition or ADU in Highland Park typically runs $45,000 to $130,000, with detached ADUs reaching $90,000 to $220,000 depending on size, finishes, and foundation work. That’s the real number before anyone digs a hole. If you’re planning a room addition, second-story build, or garage conversion in the 75205 ZIP code, the two things that will make or break your job are Highland Park’s own building department and the Blackland Prairie clay under your foundation. Barrett & Sons Construction has worked both for over 29 years, and we answer the phone at (877) 610-1318 when you’re ready to talk numbers in writing.
Highland Park is not Dallas. It’s an independent municipality entirely surrounded by Dallas, with its own permits, inspectors, and a town-level architectural review board that enforces deed restrictions going back to the original 1907 planned development. Contractors who assume Dallas jurisdiction gets stopped, fined, or forced into redesign. We don’t make that mistake, and we’ll keep you from making it too.
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Why Barrett & Sons Construction Is Highland Park’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and his sons run the crews. When we say Home Additions & ADU, we mean the owner on the job site, the owner’s name on every contract, and the owner’s phone number in your hand. That’s how we’ve built a reputation in Highland Park that national outfits can’t touch.
Highland Park homeowners see us at the hardware store on Saturday. They see our trucks on Abbott Avenue and Armstrong Parkway, not a franchise van from three states away. When a Highland Park inspector wants to walk a foundation pour or review an exterior material spec, we’re standing there with the plans, the change orders, and the answers. Local knowledge here isn’t a marketing line. It’s the difference between a framing inspection that passes and one that sends your $90,000 addition back to the drawing board for a deed restriction conflict.
Every scope of work, every allowance, every price change arrives as a written change order before any work happens. And every completed job carries the 90-Day Done Right Promise, written on the contract itself: if it’s not right, one call brings Tom back.
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Our Home Additions & ADU Services in Highland Park
Room Additions
Ground-floor room additions in Highland Park usually range $45,000 to $130,000. Before you pick a paint color, you’ll need to know what’s under your house. Older homes along Beverly Drive, Lakeside Drive, and the streets platted in the 1920s through 1950s frequently sit on unreinforced foundations. Blackland Prairie clay shrinks in Texas summers and swells in wet springs, which means any new load-bearing wall needs engineered support, whether that’s a post-tension slab tie-in or deep concrete piers. We design for that on day one, not after excavation when the surprise invoice shows up.
Second Story Additions
Going up instead of out is how many Highland Park homeowners get the square footage they want without losing yard space on lots that were never large to begin with. Second-story additions here run $45,000 to $130,000, and they trigger the town’s architectural review process in ways a ground-floor build does not. Massing, setbacks, rooflines, and exterior materials all get scrutinized against deed covenants. We coordinate with your designer or architect early so the plan that goes to the Highland Park building department is the plan that gets approved, not the plan that gets sent back for a third revision.
ADU Design & Permitting
Highland Park has its own permit path for accessory dwelling units, and it is not Dallas’s. A detached ADU here runs $90,000 to $220,000, and the first line item isn’t lumber. It’s the permit set. We handle the drawings, the town-level review coordination, and the inspector sign-offs so you’re not the one reading deed restriction language at midnight. The permit inspector works for you, not for us. That’s why we like him in the room early.
Garage Conversion ADU
Converting an existing garage into livable space runs $30,000 to $80,000 in Highland Park and is often the fastest path to a rentable or in-law unit because the structure already exists. What doesn’t exist is the insulation, plumbing, electrical service, and egress that Highland Park’s building department will require before anyone sleeps in that room. We quote those line items before we start, in writing, with no allowance left off paper.
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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 Highland Park
When we order materials for Highland Park jobs, we order brands you can look up. In kitchens and baths we install Schluter waterproofing systems and Grohe fixtures. On roofing we use GAF. That matters because Highland Park’s review board will ask what material is going on the exterior, and “whatever the supplier had” is not an answer that passes. We keep relationships with local suppliers who stock these lines, which means fewer weeks waiting on a transom or a slab system that was supposed to arrive two Fridays ago.
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Common Home Additions & ADU Problems We See in Highland Park Homes
Highland Park’s housing stock runs from 1920s Tudor and Colonial Revival estates to brand-new custom builds exceeding 5,000 to 8,000 square feet, and the problems differ by era.
– Unreinforced foundations under 1920s to 1950s homes. We regularly see original pier-and-beam or thin slab foundations under older Highland Park homes that were never built for today’s loads. Adding a second story without deep pier support is how you get cracked walls and a failed inspection. The soil under Highland Park is Blackland Prairie clay, and it moves.
– Dallas-permit assumptions that fail Highland Park review. Contractors who do most of their work across the city line in Dallas sometimes never submit to Highland Park’s architectural review board at all. Then framing starts, an inspector flags the setback, and the job stops. We see this a few times a year, always from crews that don’t work Highland Park regularly.
– Long-lead materials ordered before the price is locked. Custom millwork, architectural glass, and specialty slab systems can run 10 to 16 weeks. If a contractor orders them before you’ve signed a fixed scope, you’re arguing about change orders when the item lands. An allowance that isn’t on paper is a surprise waiting for a date. We don’t order anything until your price is fixed in writing.
– Foundation cost surprises after excavation. In Highland Park’s expansive clay, a $45,000 room addition can become a $75,000 room addition if the slab design wasn’t engineered up front. We put the pier or post-tension spec in the original estimate, not in a change order after the hole is open.
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Pricing for Home Additions & ADU in Highland Park, TX
| Project Type | Highland Park Price Range |
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| Home Addition | $45,000-$130,000 |
| ADU Construction | $90,000-$220,000 |
| Second Story Additions | $45,000-$130,000 |
| Garage Conversion | $30,000-$80,000 |
What pushes a job toward the top of those ranges? Foundation engineering on expansive clay, exterior materials that pass Highland Park’s deed restriction review, custom millwork and glass with long lead times, and the coordination time with designers and architects. What pushes it down? A smaller footprint, standard fixtures, and a plan that clears review on the first submission. We give you a written line-item estimate before any work starts, and the price doesn’t change unless you change the scope, in which case you get a written change order to sign first. Call (877) 610-1318 for your free estimate.
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We Also Serve Cities Near Highland Park
While this page is about Home Additions & ADU in Highland Park, we also serve University Park, Dallas, Richardson, and Irving. If you’re a few blocks past the town line, the same crew, the same written pricing, and the same 90-Day Done Right Promise apply.
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Serving Highland Park, TX - Our Local Coverage Area
We’re based in the Highland Park 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 - Home Additions & ADU in Highland Park
Does Highland Park require its own permits for a garage conversion ADU, or can we use Dallas permits?
Highland Park requires its own permits. It’s an independent municipality with its own building department and inspection process, and a Dallas permit will not cover any work inside the Highland Park town limits. Our team submits to Highland Park directly and handles the full review path so you’re not stuck mid-project.
How do Highland Park’s deed restrictions affect a second-story addition we want to build?
Highland Park’s town-level architectural review board enforces deed restrictions on top of the building code, which means exterior materials, setbacks, massing, and even rooflines can trigger redesign even if the structural plan passes. We coordinate with the review board early so the plan you build is the plan that was approved. Call (877) 610-1318 if you want us to look at your deed restrictions before you spend money on drawings.
Why does a home addition in Highland Park cost more per square foot than in Dallas?
Highland Park additions cost more because of the town’s separate permit and architectural review process, the prevalence of older unreinforced foundations that need pier or post-tension work, and the high-end finishes most homeowners on these streets expect. Blackland Prairie clay adds engineering cost that doesn’t exist on every Dallas lot. Our estimate tells you exactly where every dollar goes, in writing.
Can we get a fixed price for a Highland Park ADU before the permits are approved?
Yes, with a clear scope. We can’t tell you a final number if the scope isn’t defined, but once the scope, allowances, and material selections are written down, our price is fixed and any change arrives as a written change order before it happens. We don’t order long-lead items until that fixed price is signed.
How long does a second-story addition take in Highland Park compared to a ground-floor room addition?
A second-story addition in Highland Park usually runs several weeks longer than a ground-floor room addition because of the architectural review timeline, foundation and structural work on the existing frame, and lead times on long-lead items like specialty glass and millwork. On Highland Park jobs, the lead times, not the labor, usually set the calendar. Call (877) 610-1318 for a realistic schedule on your specific property.
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What Actually Sets the Calendar on a Highland Park Addition
Highland Park is not a place where you order stock windows on Tuesday and hang them on Thursday. This is a town where clients want architectural glass, custom millwork, slab systems from specific fabricators, and fixtures with a 10-week factory lead time. So here’s the honest truth about timing: the labor doesn’t set the calendar. The lead times do.
Our crew recently framed a second-story addition on a 1940s Tudor in the 4300 block of Arcady Avenue, where the original unreinforced foundation required deep concrete piers before we could set load-bearing walls. We coordinated the rough-in for a Kohler alcove tub and a custom Wellborn vanity through one inspection sign-off, then waited three weeks on a specialty leaded-glass transom from the mill shop. Proof that on Highland Park jobs, the lead times, not the labor, set the calendar. That’s also why we fix the price in writing before ordering anything with a long lead time. When a 14-week millwork item lands and the allowance was exceeded, someone is getting a change order. Better that it’s discussed and signed before the order goes in, not after the delivery truck pulls away.
Highland Park’s review board adds another layer of time. The town enforces deed restrictions alongside the building code. Exterior materials, massing, setbacks, rooflines. A contractor who assumes Dallas jurisdiction won’t just get slowed down; they’ll get stopped. We plan for Highland Park’s process from the first conversation, not as damage control at the framing inspection.
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Call Barrett & Sons Construction for Your Highland Park Addition or ADU
If you’re planning a room addition, second-story build, garage conversion, or detached ADU in Highland Park, call us at (877) 610-1318 for a free estimate. You’ll get a written line-item scope, pricing that doesn’t shift unless you change the scope, and the 90-Day Done Right Promise on paper. Tom Barrett’s name, address, and license number are published and verifiable. Ask anyone on your street, or look us up yourself. Then call.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Highland Park with owner-operated home additions and ADUs since 1998.