Beyond the unit price: budgeting your ADU project
The unavoidable costs every ADU project carries on top of the unit, whether you build with Nestron, another prefab, or on site. Nestron buyers typically land at ~$80K to ~$150K all in.
A recent r/AccessoryDwellings thread, titled “Neighbor’s cost of building an ADU in San Diego came in at $340K and the breakdown was eye opening,” has been making the rounds. 180+ upvotes, 160+ comments, mostly from people sharing their own surprise totals.
We see the same surprise at Nestron. Prospects who get excited about a unit at $49,800 to $89,800 sometimes go quiet after a local contractor walks the lot and comes back with another $25K to $50K in site work, permits, and fees. The all-in number doesn’t match the unit number, and it can feel like something was withheld.
Every legal ADU carries the same local costs on top of the unit, no matter who built it. What changes the headline total is the unit itself. A site-built or large-format prefab ADU drives totals like the $340K project above. A Nestron unit, fully built and finished in the factory, keeps the headline far lower.
Typical Nestron project, all in
- Unit (factory-built and finished)$49,800 – $89,800
- Shipping + delivery $15K – $25K
- Local site work, utilities, permits, fees $15K – $40K
- All-in total~$80K – $150K
This piece walks through two real Nestron projects (one harder lot, one simpler) and how to build a budget for your own.
Two real Nestron projects, end to end
The clearest way to show what an all-in number looks like is to walk through real examples. Both come from recent customers. Numbers anonymized and rounded.
High-end example: Pacific Northwest customer with above-average site challenges. Dead-end street that required road closure permits for craning, and existing utility lines about 8 feet deep that made the sewer tie-in more involved than usual.
| High end · harder lot | Project total~$122,000 |
| Nestron Cube Two (base unit, fully built) | $69,800 |
| Shipping + port-to-site delivery | $20,000 |
| Foundation (4 concrete pier footings) | $3,000 |
| Water line tie-in | $1,500 |
| Power conduit + tie-in | $3,000 |
| Sewer line (8 ft deep) | $8,000 |
| Craning with road closure permits | $10,000 |
| System Development Charge (deferrable, ~$60/mo over 120 months) | $7,000 |
Low-end example: Florida customer on a straightforward site. Flat lot, utility mains close to the build, easy crane access, and a lower-fee jurisdiction typical of much of the Southeast.
| Low end · simpler lot | Project total~$101,800 |
| Nestron Cube Two (base unit, fully built) | $69,800 |
| Shipping + port-to-site delivery | $20,000 |
| Foundation | $3,000 |
| Utility connections (water, sewer, power) | $2,000 |
| Crane + installation | $5,000 |
| Permits + impact fees | $2,000 |
Across our customer base, the local-cost portion of an ADU project typically falls $15K to $40K. Harder lots like the Pacific Northwest example run higher; simpler lots come in lower.
Soft costs (permits, design, engineering, plan check, financing) typically account for 10% to 25% of total project budget, per Terner Center for Housing Innovation at UC Berkeley.
What’s in your Nestron pricing, and what comes from local?
The advertised Nestron unit price covers what we build and what we directly control. Local-cost categories come from local contractors operating under local code.
| In your Nestron pricing | From local contractors |
| The unit, fully built and furnished | Permits, impact and connection fees |
| Product design and architectural drawings | Foundation work |
| Jurisdictional permitting audit | Utility trenching and tie-ins |
| Shipping coordination | Crane operation |
| Installation coordination with your local contractor | General contractor coordination fees |
We don’t quote local costs because we can’t quote them accurately. Permit fees, utility distances, and labor rates all vary by location. A vertically integrated builder will quote one all-in number, but that number typically carries a 20% to 30% markup on the local work to cover their risk. Most Nestron buyers come out ahead paying actual local cost with direct visibility into the bids.
Build your own budget
- Unit + delivery
Unit prices: $49,800 (Cube One, Legend One), $69,800 (Cube Two, Legend Two), $89,800 (Cube Two X). Add shipping at $15K to $25K. Your project manager confirms a current shipping estimate close to your purchase date.
2. Site cost
Get a written estimate from a local GC, civil engineer, or permit expediter covering site prep, foundation, utility tie-ins, permit and impact fees, and any code-required additions. Typical lots land $15K to $40K.
3. Contingency
Add 15% on top of the combined total. Most buyers don’t use most of it; it covers the rare surprise like unexpected soil conditions or an old septic that needs decommissioning.
Typical all-in by model, standard lot:
Cube One / Legend One 254 sq ft
Unit price $49,800
Typical all-in~$80K – $120K
Cube Two / Legend Two 328 / 375 sq ft
Unit price $69,800
Typical all-in~$100K – $135K
Cube Two X 398 sq ft
Unit price $89,800
Typical all-in~$120K – $150K
What does the all-in number cost per month?
~$840/ month
$120K all-in financed over 30 years at current home equity rates (~7.5%).
Why this monthly figure works
- Nestron units are permitted as permanent homes, so financing rates track traditional home loans (well below tiny-home or RV rates).
- Most buyers use the unit as a rental, family suite, or downsize. Rental income or alternative housing cost usually covers the monthly payment.
Common financing routes
- HELOC or cash-out refinance
- Construction loan
- Renovation loans: Fannie Mae HomeStyle, Freddie Mac CHOICERenovation
- Specialty ADU lenders
Nestron partners with RenoFi for buyers who want a vetted option, and you’re free to use your own bank or a mortgage broker who has financed ADU projects before.
Bottom line
Nestron’s expertise is building well-designed tiny homes at market-leading value and getting them to your lot ready to live in. Our mission is to make homeownership simpler and more accessible for more Americans, whether the unit becomes a first home, an in-law suite, or a rental investment to grow wealth.
Permitting requirements are complex and different in every US county. We’d love to be experts in every one, but we can’t. We support your project as much as we can along the way. Local costs beyond the unit are unavoidable for any serious ADU project, whether you build with Nestron, choose a competitor, or go stick-built.
Those local costs typically add $15K to $40K, plus $15K to $25K for shipping. The Nestron unit price is what we control, and we hold it firm. Most customers land ~$80K to ~$150K all in.
Have a specific lot in mind? Your Nestron project manager can walk through your numbers with you. The full lineup is at Nestron.
