Real Construction Cost Calculator: what your house actually costs in the end

Why the catalogue price almost never matches the final price

Hardly any figure in house building is as tempting — and as deceptive — as the catalogue price of a prefabricated house. It appears large in the brochure, is displayed on the price boards of the show-house parks and is presented in advertisements as the price. Yet hardly anyone reads the fine print about what this amount really covers: as a rule, it refers to the erected house “from the top edge of the floor slab” in the advertised finishing level. Everything that turns a house body into a habitable home is missing from it. This is exactly where the nasty surprise sets in for many homeowners — and this is exactly the gap our honesty calculator lays bare.

The first major item missing from the catalogue price is the foundation. Whether floor slab or full basement — the decision quickly makes a difference of several tens of thousands of euros. Earthworks, soil survey, sealing and a frost skirt must be paid for before the house is even delivered. A basement creates valuable usable space, but easily costs three times as much as a floor slab. Anyone who calculates too optimistically here punches a hole in the budget before the topping-out ceremony.

The second major chunk is the ancillary construction costs (Baunebenkosten). You should plan about 15 percent of the pure construction sum for this, in the worst case up to 20 percent. These include building permit and structural verification, surveying and soil survey, servicing and the utility connections for electricity, water, waste water and telecommunications, plus construction water, construction electricity, construction insurance and building acceptance. These items look like formalities, yet they add up to five-figure amounts. You can find a detailed breakdown in our guide on ancillary construction costs.

Shell-finish house, kitchen and garden: the hidden budget eaters

Anyone who opts for a shell-finish house (Ausbauhaus) deliberately pushes down the catalogue price — and in return takes on part of the interior fit-out themselves. This is a legitimate and often clever way to save. But “shell-finish house” does not mean “ready to move into”: painting, floor coverings, some interior doors and the final plumbing installation are still outstanding. Even those who do a lot as self-performed work pay for materials and tools and put in considerable time. For these trades, our calculator therefore adds a realistic extra item for the shell-finish house — this is precisely where homeowners underestimate their budget especially often.

Two further items are almost always missing from the brochure, but are indispensable: the kitchen and the outdoor works. A fitted kitchen of solid quality quickly costs 15,000 to 20,000 euros, with no upper limit. The outdoor works too — driveway, terrace, fence, carport preparation and planting — come to a five-figure amount. Anyone who skips these items during planning ends up with a finished house, but with an exhausted budget and an unfinished plot.

Region and plot: the decisive levers

Finally, the region determines the level of tradespeople's wages and thus the final price. In southern Germany, especially around Munich and Stuttgart, construction costs are well above the national average, while in large parts of eastern Germany building is cheaper. Our calculator accounts for this effect via a regional surcharge or discount. And not to be forgotten: if you do not yet have a building plot, this — depending on the location — largest single item, plus property transfer tax, notary and land registry, is added on top. Anyone who honestly adds up all these factors goes into the bank meeting with a reliable budget. A complete overall calculation including a reserve is additionally provided by our prefabricated house cost calculator. The official construction price indices are provided by the German Federal Statistical Office (Statistisches Bundesamt).