Honest ranges for ADUs, shops, garages, pole barns, and storage buildings in southeastern North Carolina. Not a quote — a starting point so you can tell whether your budget is in the right neighborhood before anyone comes out.
Because numbers create accountability, and because every site is different. Both of those are true. But refusing to give anyone a range wastes everybody's time — you end up sitting through three sales visits before you learn a project is double your budget.
So here is the honest version: the ranges below are what projects actually cost in New Hanover, Brunswick, Pender, and Onslow counties. The spread is wide because finish level, foundation type, site access, and utility work genuinely move the number that much. Where you land inside a range is a conversation, not a mystery.
Stick-built, permitted, finished living area. Excludes site work and fees.
| ADU Type | Size | Typical Range | Per Sq Ft |
|---|---|---|---|
| Studio ADU / backyard cottage | 300–450 sq ft | $60K–$115K | $190–$260 |
| One-bedroom ADU / guest house | 500–650 sq ft | $90K–$170K | $180–$260 |
| Two-bedroom ADU / in-law suite | 700–900 sq ft | $130K–$235K | $180–$260 |
| Garage apartment (living space above garage) | 600–800 sq ft + garage | $120K–$260K | varies |
| Garage conversion to ADU | 400–600 sq ft | $55K–$130K | $130–$220 |
| Attached ADU / in-law addition | 400–800 sq ft | $70K–$190K | $170–$240 |
| Pool house with full bath & kitchenette | 200–400 sq ft | $45K–$110K | $210–$280 |
Permitted, coastal wind-engineered. Shell plus basic electrical; interior finish varies.
| Shop Size | Square Feet | Typical Range | Notes |
|---|---|---|---|
| 24×30 workshop | 720 | $35K–$60K | Hobby shop, one to two bays |
| 30×40 shop | 1,200 | $55K–$95K | Most requested size |
| 40×60 shop | 2,400 | $85K–$140K | Working shop, lift-capable |
| 50×80 shop | 4,000 | $130K–$250K+ | Small commercial scale |
| Insulation package | — | +$4–$10 / sq ft | Batt or spray foam |
| Bathroom (half / full) | — | +$8K–$22K | Under-slab plumbing required |
| Mezzanine / loft | — | +$25–$55 / sq ft | Cheapest square footage available |
| Mini-split HVAC | — | +$4K–$12K | Per zone, sized to insulation |
Slab or pier foundation, overhead and walk doors, siding matched to your home.
| Garage Type | Common Size | Typical Range | Notes |
|---|---|---|---|
| One-car detached | 14×24 | $12K–$28K | Minimal storage |
| Two-car detached | 24×24 | $18K–$45K | Highest-volume build |
| Two-car with storage depth | 24×28–24×30 | $24K–$55K | Room for a bench |
| Three-car detached | 24×36 | $30K–$65K | Three bays |
| Four-car / garage-plus-shop | 30×40+ | $45K–$95K | Best value per bay |
| RV or boat garage, tall door | 16×40, 14–16 ft walls | $40K–$95K | 12–14 ft overhead doors |
| Loft / attic storage | — | +$6K–$20K | Storage-rated trusses and stair |
| Carport, freestanding | 20×20 | $6K–$18K | Cover without enclosure |
Post-frame construction, engineered for the applicable coastal wind zone.
| Structure | Common Size | Typical Range | Notes |
|---|---|---|---|
| Small storage building | 12×20 | $8K–$20K | Yard and lawn equipment |
| Open-sided pole barn | 24×30 | $12K–$30K | Roof and columns, open walls |
| Enclosed storage building | 30×40 | $25K–$60K | Sided, lockable, doors |
| Large equipment / ag building | 40×60 | $45K–$110K | Tractors, implements, hay |
| Boat / RV storage, tall | 16×40+ | $30K–$80K | 12–14 ft doors |
| Horse barn with stalls | 36×36 | $45K–$120K | Stalls, tack, ventilation |
| Lean-to addition | 12 ft deep | +$25–$55 / sq ft | Along either long wall |
| Concrete slab (vs. gravel) | — | +$7–$14 / sq ft | Thickness and reinforcement dependent |
Two identical buildings on two different lots can differ by $40,000. Here is where it comes from.
Trees, stumps, slope, wetlands, poor soil, and whether a concrete truck can physically reach the pad. Clearing and grading commonly runs $2,000–$15,000, and a difficult site can go well beyond that. This is the single most underestimated line item.
Running water, sewer, and power to an outbuilding costs real money based on distance and obstacles. For an ADU on septic, capacity is the make-or-break question — a system expansion can run $8,000–$25,000, and a new system more. City sewer connection means impact fees.
Gravel floor, monolithic slab, thickened-edge slab, stem wall, or piers. A slab adds roughly $7–$14 per square foot over gravel, and lift-rated or elevated foundations cost more again. Flood zone elevation requirements can change this dramatically.
On an ADU, the same 600 square feet can be built for $110,000 or $170,000 depending on cabinets, countertops, flooring, fixtures, and trim. On a shop, it is insulation, interior sheathing, lighting, and whether you condition it.
Every foot of wall height and every foot of door width costs money in framing, headers, and hardware. A 14-foot overhead door is not a small upgrade over a 9-foot door — it changes the structure around it.
Permit and impact fees, surveys, soil evaluations, stormwater review, engineered drawings, and any variance application. On an ADU these commonly total $3,000–$15,000+ depending on jurisdiction and whether you need a variance.
Higher wind zones mean more fasteners, heavier connectors, stronger doors, and specific roof attachment. Flood zone parcels may require elevated construction and flood venting. Non-negotiable, and priced into every job we do.
Material pricing and subcontractor availability move. We hold written proposals for a defined period and tell you plainly when a number is exposed to a commodity we cannot lock.
A free estimate is not free. It is paid for by the customers who sign, which means honest people subsidize tire-kickers — and it pushes contractors toward optimistic numbers that climb once you are committed.
We charge $250 for a site visit and a written, itemized proposal. We come out, take real measurements, check setbacks and site constraints, and put a number on paper that we will stand behind. The $250 is credited back to your project at contract signing.
If you are comparing three contractors and two gave you a verbal ballpark over the phone, you do not have three estimates. You have one estimate and two guesses.
Request an EstimateRanges get you oriented. A site visit gets you a number. $250, credited back at signing.