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 Boulder City
Adding a room, a second story, or a detached ADU in Boulder City typically runs $45,000 to $130,000 for a home addition and $90,000 to $220,000 for a full detached ADU, depending on whether the lot sits inside the Historic District or on county-governed acreage with septic and well setbacks. Tom Barrett and his sons have built additions and ADUs across Boulder City for years, and we’ve learned that the real cost drivers here aren’t what most contractors talk about: they’re the Historic Preservation Commission review on 1930s Bureau of Reclamation bungalows, septic leach field setbacks on acreage lots, and freeze-thaw cycles that punish shortcuts in concrete and exterior sealing. Call (877) 610-1318 and we’ll walk your property, pull the county records, and give you a written line-item quote before you sign anything.
We’re Home Additions & ADU builders who live in the same valley you do. That matters when the job is a detached ADU off Adams Boulevard or a second-story addition on a Mission Revival bungalow in the 89005 zip. We know which lots are on city sewer and which still run septic. We know which streets sit inside the Historic District overlay and which don’t. And we know that a written change order beats a surprise invoice every single time.
Why Barrett & Sons Construction Is Boulder City’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998 and his sons run the crews. When we say someone with the Barrett name will be on your Boulder City job site, we mean it literally, not as marketing. That’s why our Boulder City customers tend to be folks who’ve already been burned once by a national outfit that quoted one number on the phone and handed them another at the door. We answer our own phone, we publish our license number, and every price change arrives in writing before a single nail moves.
Boulder City isn’t a big town. People talk. If we cut a corner on a sunroom off Nevada Way or mishandled a permit on a garage conversion near Lake Mead, you’d hear about it at the hardware store by Saturday. That accountability is the whole model. Tom lives twenty minutes away and wants to know if something isn’t right. Our 90-Day Done Right Promise is written on every contract: one call brings him back.
The crew members who show up at your Boulder City property are background-checked, uniformed, and they carry the Barrett & Sons name. They’re not dispatched strangers. They’re the same people who’ll wave at you at the coffee shop next month. That’s the difference between an owner-operated company and a revolving door.
Our Home Additions & ADU Services in Boulder City
Boulder City gives us two very different job profiles, and we scope them differently. Inside the Historic District, the job is about period compatibility and review timelines. Outside it, on acreage lots governed by Clark County rather than city rules, the job is about septic, wells, drainage, and material hauling. Here’s how we handle the work most Boulder City homeowners call us for.
ADU Design & Permitting
A detached ADU in Boulder City’s Historic District doesn’t just need a building permit. Any exterior modification visible from the street, including massing, window style, and roofing material, goes before the Historic Preservation Commission. We draw ADUs that match Mission Revival proportions from day one, because resubmitting a modern box costs you three weeks and a change order. On acreage outside the Historic District, we’re dealing with Clark County permitting, septic and well setback verification, and sometimes a soils report before we ever quote foundation work.
New Detached ADU
A new detached ADU in Boulder City runs $90,000 to $220,000. That range exists because a flat lot on city sewer with good access is a very different job from an open desert parcel where septic setbacks force the ADU to shift, well lines run through the build area, and every sheet of plywood gets hauled up from the Las Vegas valley. We scope all of it before you sign. On a mid-century ranch off Adams Boulevard in 89005, we built a 600-square-foot detached ADU with a KraftMaid kitchenette. The lot was on septic, so we surveyed the leach field and shifted the foundation five feet to keep the required 10-foot setback. That’s the kind of thing that doesn’t show up on a cheap quote until the rough-in is already dug.
Garage Conversion ADU
Converting an attached or detached garage in Boulder City runs $30,000 to $80,000. This is often the most cost-effective way to add a rental unit or in-law suite, because the shell already exists. But garage conversions have their own surprises: slab elevation often sits below the floodplain requirement, electrical service needs an upgrade, and older Boulder City garages sometimes have slab edges that freeze and heave more than newer construction. We pull permits on every conversion, because an unpermitted ADU will come back to haunt you at sale.
Junior ADU & Interior Conversion
A junior ADU, typically an interior conversion of a large bedroom, den, or bonus room into a self-contained living space with efficiency kitchen and private entry, is one of the fastest ways to add income or family space in Boulder City without changing the footprint. Because it’s interior work, it often avoids the Historic Preservation Commission exterior review entirely, which saves real time. But it still requires permitted plumbing and electrical work, and we write every allowance and every scope change in writing before work proceeds.
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 Boulder City
We don’t install mystery brands off a van. On Boulder City additions and ADUs you’ll see materials you can look up: KraftMaid in kitchenettes, Schluter systems in bathroom and wet areas, GAF on roofing where it ties into the existing structure, and Grohe fixtures in bathrooms where a homeowner wants German engineering without the showroom markup. Because we haul our own materials up to Boulder City on our own flatbed, we’re not at the mercy of supplier delivery schedules or the surcharges some distributors tack onto mountain-area deliveries. That keeps your timeline and your price predictable.
Common Home Additions & ADU Problems We See in Boulder City Homes
- Historic District review flags a window style mid-project. A homeowner picks a modern window unit, the HPC review catches it, and now there’s a three-week delay and a change order while period-compatible units are special-ordered. We pre-check window specs against HPC guidelines before we submit.
- Septic and well setbacks force a redesign after rough-in is quoted. On acreage outside the Historic District, county jurisdiction controls septic setbacks. If nobody surveys the leach field before the quote, the ADU foundation ends up five feet from where the plan said, and you pay for the redesign. We survey first.
- Open desert lots without drainage swales send monsoon runoff under the new slab. Boulder City sits high in the Mojave, and when the summer monsoon hits, water wants somewhere to go. If grading wasn’t in the original scope, the first storm runs water under your new addition. Grading and drainage scoping is part of our site prep, not an afterthought.
- Freeze-thaw cycles crack concrete slab edges and stress stucco. Boulder City’s elevation means occasional hard freezes that Las Vegas proper rarely sees. That expansion and contraction punishes shortcuts in slab pours and exterior sealing. We spec concrete and sealants for thermal cycling, not just for the mild winters most contractors assume.
Pricing for Home Additions & ADU in Boulder City, NV
Here are the honest ranges for Boulder City work. A full home addition runs $45,000 to $130,000. A new detached ADU runs $90,000 to $220,000. A garage conversion runs $30,000 to $80,000. What moves you within those ranges: whether you’re inside the Historic District and need period-compatible materials, whether the lot is on septic with limited leach field room, whether we’re hauling up a steep grade or across open desert, and whether the existing structure was built in 1938 or 1988. We give you a written line-item quote before work starts, and every scope change comes as a written change order. No surprises at the end. Call (877) 610-1318 to schedule your free estimate.
| Project Type | Boulder City Price Range |
|---|---|
| Home Addition | $45,000 - $130,000 |
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion | $30,000 - $80,000 |
Those ranges are for Boulder City specifically. They account for the elevation, the drive time, the Historic District review where it applies, and the septic and well work that acreage lots require. We don’t quote Boulder City work off a Las Vegas price sheet and add a mystery surcharge. We scope the actual lot.
We Also Serve Cities Near Boulder City
Beyond Boulder City itself, Barrett & Sons serves Henderson, Whitney, Paradise, and Enterprise. If you’re close to the Boulder City line and wondering whether we’ll come out, the answer is almost always yes. We coordinate dispatch and scheduling from our Las Vegas office, but crews work locally in Boulder City and the surrounding communities every week.
Serving Boulder City, NV - Our Local Coverage Area
We’re based in the Boulder City 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 Boulder City
Yes. Any exterior addition or modification visible from the street within the Boulder City Historic District must go before the Historic Preservation Commission for design review before you can pull a building permit. That review covers massing, window style, roofing material, and exterior finish. A detached ADU that matches the Mission Revival proportions and materials of the original 1930s Bureau of Reclamation bungalow can move through smoothly; a modern box will get sent back. We draw to HPC standards from the first sketch so you don’t burn three weeks on a resubmission. Call (877) 610-1318 and we’ll tell you early whether your lot sits inside the overlay.
The typical issue is that the leach field sits closer to the planned build area than Clark County’s required 10-foot setback allows, so the ADU foundation has to shift. Nobody surveys the leach field, the quote gets written, and then the redesign hits after rough-in is underway. We survey the septic and well lines before we quote, so the foundation location in the quote is the foundation location on the ground. That one step saves thousands in change orders. For an exact quote on your Boulder City lot, call (877) 610-1318.
Because Boulder City sits outside the normal delivery radius for many Las Vegas valley suppliers, and some distributors add a mountain-area or extended-radius surcharge on top of the base delivery fee. We haul our own materials up on our own flatbed from the Las Vegas valley, which removes that surcharge entirely. It also means we control the schedule instead of waiting on a supplier’s truck to find room for a Boulder City run. Call (877) 610-1318 and ask us to quote the material logistics on your specific lot.
Yes, and not just any engineer: one who understands 1930s Bureau of Reclamation framing, which includes original wood members sized differently than modern dimensional lumber. The existing load path has to be verified before a city or county inspector will sign off on the new gravity loads. We bring in a structural engineer who has worked on Boulder City historic housing stock before, so the stamp doesn’t turn into a three-month back-and-forth. For a second-story addition on your bungalow, call (877) 610-1318 and we’ll tell you what the engineer will need to see.
Boulder City’s elevation near 2,500 feet means occasional hard freezes that Las Vegas proper rarely sees, and the thermal cycling between freezing nights and intense Mojave sun stresses concrete joints, slab edges, and any masonry interfaces. A slab poured without proper control joints and subgrade preparation will show edge spalling and hairline cracking within a few seasons. We spec Boulder City slab work for thermal cycling: deeper footings where freeze risk is real, proper expansion joint placement, and sealants rated for high UV plus freeze-thaw. Call (877) 610-1318 for a slab quote on your Boulder City ADU or shop.
If you’re thinking about a home addition, a detached ADU, or a garage conversion in Boulder City, and you want a contractor who puts the whole scope in writing before the first nail moves, call Tom Barrett and his sons at (877) 610-1318. We’ll walk the lot, pull the county and city records, and give you a written line-item estimate. Free. No trip charge inside the county. And if you’re 65 or over, or a veteran, ask about the permanent 10% discount.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Boulder City since 1998.