Cost of Prefab Homes 2026: Unit, Delivery, Site, and Permits
The unit is about a quarter of what you will spend. Deltec says its shell is about 1/4 of the total, and that the total runs $250 to $600 per square foot. Mighty Small Homes prices its 600-square-foot kit at $48,144 and its own finished estimate at $120,360 if you build it yourself, or $192,576 to $240,720 with a builder.
Your budget also has to cover the truck, the crane, the ground, and the county. Every figure below comes from the maker's or the county's own page. Where nobody publishes a figure, the cell says "not published". Get that number in writing before you pay anything.
Layer 1: the unit
Deltec has advertised a discounted shell price of $47,924. We used the regular price. Backcountry Hut prices are in Canadian dollars, and the US figure is its own conversion of $274,698 CAD.
Layer 2: the truck and the crane
No maker we read publishes a crane price. Backcountry Hut says the client unloads its System S and strongly recommends a crane to do it. Get the crane in the delivery quote as its own line.
Layer 3: the ground and the utilities
Hookup and trenching costs are set by the lot and the local utility. We found no national .gov figure for them, so this piece does not give one.
Layer 4: the county
Permit fees are set locally. These 3 fee schedules show the range for 2026.
The Warren County sum is 600 x $0.35 = $210, plus $25, plus $75. Essex is 600 x $0.20 = $120, plus 3 x $75, plus $75. Thurston's figure is base fees for the septic approval alone, before the building permit and before anyone digs.
The all-in at 3 price points
As an example only, using the makers' own finished estimates. Neither includes land.
The arithmetic: $120,360 minus $48,144 is $72,216, and $120,360 divided by 600 is $201. For Deltec, $278,019 minus $59,905 is $218,114, of which $35,000 is the site allowance, and $278,019 divided by 746 is $373. Deltec calls its number an estimated minimum, and freight and sales tax sit on top of it. Add Warren County's fees to the Hideaway, and the permit layer is 746 x $0.35 = $261, plus $25, plus $75, or $361. Next to the $218,114 gap, that is small.
What the layers say
The unit is 20% to 40% of the finished cost. Mighty Small Homes' kit is 40% of its own self-build estimate and 20% to 25% of its builder estimate, and Deltec's shell is 22% of its total.
Price per square foot on the quote understates the build by a factor of 2.5 to 5. The Modern 600 is $80 per square foot as a kit and $201 to $401 finished, on the maker's own numbers.
Delivery is the layer makers publish least consistently. DEN includes it, Avrame charges $3.25 per mile, Backcountry Hut budgets up to $20,000 CAD per truck, and Deltec and Zook publish nothing.
Septic paperwork can cost more than the building permit. Thurston County's septic fees total $2,467, against $310 for Warren County's whole permit stack on a 600-square-foot unit.
Before you order
Do these 3 before any money moves.
- Price the ground. Run the lot through the site-prep cost estimator, and read the raw land guide if the parcel has no utilities yet.
- Confirm the loan. Start with the lender locator. A lender needs the all-in figure, and the maker's quote covers 1 layer of it.
- Pull the county fee schedule. Search the county's own site for the current year's schedule and add every line that applies, septic included.
For running costs after the build, see what it costs to run an Airbnb. For finished units, see the 8 best prefab cabins, rated, and for a village built from small units, the Evergreen Cabins playbook.
Host Camp is not a licensed tax, legal, or financial adviser. Confirm figures for your situation with a professional.
