Research
Labour is 45–60 % of a turnkey small house. Materials are the cheap part.
A finished 25 m² house in Sweden sells turnkey for roughly 800,000–1,400,000 SEK. The materials in it cost about 212,000 SEK. We traced where the rest goes, priced a bare structural shell line by line, and drew the honest conclusion: the affordability case for self-build runs through deleting purchased labour rather than through cheaper materials or clever machines.
Finding
Purchased labour is 45–60 % of the cost of a turnkey small house in Sweden. A bare structural shell plus envelope for ~30 m² costs about 96,500 SEK in materials (~3,200 SEK/m²); scoping up to a habitable house lands at roughly 8,000–16,000 SEK/m² in materials. Self-build with machine-cut parts is the one delivery model that moves the labour slice to the family instead of paying for it: our estimate is that a self-built house lands 40–55 % below turnkey price.
Two caveats belong inside the finding rather than in a footnote. First, a self-built shell is not cheaper per m² than a volume-produced market shell kit, because kit makers buy at volume. Second, if the same hours are instead bought as unskilled bulk labour at ~300 kr/h, the cost advantage halves rather than disappears. The lever is the family's own hours. That is why the software's whole job is to make those hours possible for people who have never built.
Method
We built a line-item bill of materials for a conventional ~30 m² stud-frame shell with an insulated, airtight envelope on screw piles, priced against published Swedish building-retail prices (July 2025–2026), and cross-checked it against costs reported by real Swedish self-builders. We then compared the total against published turnkey and shell-kit prices for the same size class, and against materials figures published by Swedish house suppliers. The labour share and hourly rates come from published market prices for carpentry and unskilled construction labour. Every number below carries its source; the full tables with links live in the underlying research files.
Numbers
| Item | SEK |
|---|---|
| Structural lumber (~1.9 m³ C24) | ~15,800 |
| Sheet goods (gypsum incl. storm board, partition ply, floor ply) | ~13,700 |
| Insulation (stone wool) | ~12,100 |
| Membranes and tape | ~3,400 |
| Fasteners / brackets | ~6,000 |
| Roofing (sheet metal) | ~4,000 |
| Cladding (wood facade) | ~10,800 |
| Foundation (screw piles) | ~22,000 (the single largest line, ~22 %) |
| Waste and consumables (~10 %) | ~8,800 |
| Total | ≈ 96,500 (~3,200 SEK/m²; plausible band 79,000–121,000) |
| Option | SEK/m² |
|---|---|
| Market shell kit, self-assembled (Easy House class) | ~6,500–8,300 |
| Self-built habitable house, no paid labour (our estimate) | ~13,000–21,000 |
| Same size class, turnkey | ~13,300–22,800 |
| Conventional new villa (Swedish average) | ~28,000–40,000 |
Assumptions: 2025–26 Swedish retail prices; screw-pile foundation (cheaper than concrete in both money and hours); a labour target for a full home of H ≈ 120 + 16·A person-hours (A = floor area in m²), which is a target to be measured rather than a result; unskilled bulk labour at ~300 kr/h, mid-range carpenter at ~650 kr/h.
What this does not show
- No Kult house has been built and priced end to end. The per-m² band for a self-built house is a modelled estimate; the first measured number publishes when the instrumented room module is priced end to end.
- The labour-hours target (H ≈ 120 + 16·A) is unproven. It is a standing kill criterion on the prototype programme: if measured hours extrapolate past it, the affordability thesis fails, and we will say so.
- "Cheapest" is not the claim. On raw shell cost per m², a volume kit beats self-cut parts; comparable open-source projects warn that their own cut chassis can cost more in material than conventional framing. Kult's claim is a finished, code-checked home at 40–55 % below turnkey, and it holds because the family supplies the hours.
- Land, permits, service connections and financing costs are excluded throughout; they vary by plot and municipality.
Sources
- Formhus — what an attefallshus costs (materials ~212,000 SEK for 25 m²): formhus.se
- Storhögna Trähus — build-cost breakdown, turnkey range: storhognatrahus.se
- Easy House — shell-kit vs turnkey prices: easy-house.se · LT Ingenjörsbyrå — villa cost per m²: ltingenjorsbyra.se
- WikiHouse — cost model and FAQ (chassis-vs-home scope; self-cut material caveat): wikihouse.cc/cost
- Byggahus forum — reported materials cost for a real 30 m² self-build: byggahus.se
- Kult internal research, "Pillar 6 — economics" and "Value-chain position" (2026-07-10/11) — full BOM tables, labour-rate sources, delivery-model comparison.
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All papers
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