In brief
For a KfW-40 house, expect turnkey costs of around €280,000 (100 m²) to €540,000 (180 m²) in 2026 — about 5 to 10 percent more than a house built to the statutory minimum standard (GEG). The Efficiency House 40 standard means: only 40 percent of the primary energy demand of a reference building, achieved through top insulation, triple-glazed windows, a heat pump, a ventilation system with heat recovery and usually photovoltaics. In return there are low-interest KfW loans (up to €150,000 per unit in the Climate-Friendly New Build programme with QNG seal) and permanently low energy costs of often under €1,000 per year.
What a KfW-40 house as a prefab home costs – the overview
With the KfW-40 house as a prefab home, prefab construction pays off above all in the price: a binding fixed price ex works protects against nasty surprises, the short build time lowers the interim financing costs and the high energy standard gives you access to KfW funding in 2026. It is precisely these three levers that keep the calculation predictable.
The wall and ceiling elements are built to the millimetre in weather-protected factory halls, and the shell often stands on the building site after just one to three days. Less time on the building site means less weather risk – and that also lowers the price in the end.
This speaks in favour on price
- Binding fixed price – calculable from the start
- Short build time reduces the interim financing
- High energy standard secures KfW funding
- Price can be adjusted deliberately via the finishing stage
This drives the price up
- An upmarket selection of finishes can raise the per-m² price considerably
- The plot and incidental building costs always come on top
- Subsequent floor-plan changes cost a lot
Putting per-square-metre costs and the total price 2026 in context
The price for a KfW-40 house as a prefab home depends decisively on the finishing stage: turnkey, the per-square-metre costs in 2026 are around 2,000 to 3,500 EUR/m², as a shell house from about 1,300 EUR/m². From €280,000 is a realistic starting price for the turnkey basic version.
In addition to the pure house price, factor in the incidental building costs (around 15–20 % of the construction sum), earthworks and a buffer. With our cost calculator you can determine your individual total price. How each price factor works is shown on the Prefab house prices 2026 page.
For a KfW-40 house, reckon on turnkey costs of €280,000 to €540,000 in 2026. The additional costs compared with the GEG minimum standard usually pay off through promotional loans and energy savings within 10 to 15 years. Realistic price ranges by living area:
| Living area | KfW 40 | KfW 40 with QNG seal | KfW 40 Plus (with PV & storage) |
|---|---|---|---|
| 100 m² | €280,000 – 315,000 | €295,000 – 330,000 | €310,000 – 350,000 |
| 120 m² | €325,000 – 365,000 | €340,000 – 385,000 | €360,000 – 405,000 |
| 140 m² | €375,000 – 415,000 | €395,000 – 435,000 | €415,000 – 460,000 |
| 160 m² | €420,000 – 465,000 | €440,000 – 485,000 | €465,000 – 510,000 |
| 180 m² | €460,000 – 505,000 | €485,000 – 525,000 | €510,000 – 540,000 |
Values excluding plot and ancillary construction costs (15 to 20 percent). In the Climate-Friendly New Build programme, the KfW provides funding with low-interest loans — with the QNG seal up to €150,000 per unit. Many prefab house manufacturers now deliver KfW 40 as standard, which steadily lowers the additional costs. As of 2026.
