Apartment building construction costs per m² of gross floor area

Figures published in 2026 for a new apartment building run from around 2,000 to over 5,000 euros per square metre of habitable area. The range therefore exceeds a factor of two.

The lowest and highest differ by a factor of two and a half. A logical contradiction is worth noting: the lowest figure is presented as including all ancillary costs under DIN 276, while one of the higher figures is expressly labelled as construction cost excluding ancillary costs and excluding foundations. A figure with a larger scope therefore sits well below a figure with a smaller one. At least one of the two cannot be right.

For your own cost planning the same rule follows as throughout this branch: figures without complete qualifiers cannot be computed with. The conversion calculation for a figure found online is set out in the article on detached house construction costs and applies here unchanged.

Multi-storey housing is consistently cheaper per square metre than a freestanding house. Three robust reasons account for it.

Fixed cost degression. Heating plant, utility connections, site establishment, servicing and basic design services arise largely independently of the number of dwellings and spread across a multiple of the floor area.

A better envelope ratio. A multi-storey form with dwellings stacked above one another needs considerably less external wall, roof and foundation area per square metre of usable area. The same principle explains why a terraced house costs less than a detached one: two expensive external walls disappear and are replaced by cheaper party walls.

Repetition. Similar layouts stacked above one another reduce design effort, set-up times and material waste, and improve the position at tender because larger quantities are called for under each item.

These effects are why construction method matters less for apartment buildings than for detached houses. Masonry and prefabricated systems occupy a similar price band here, because the prefabrication advantage recedes against the scale effects of multi-storey construction.

Against those savings sit items that are absent or much smaller in a single dwelling. They consume a substantial part of the scale advantage.

Underground parking is the largest single item here and the most frequently underestimated. It can shift the building cost of the whole scheme noticeably, and it enters gross floor area in full without contributing any habitable area.

Which of these requirements bite at which threshold depends on the applicable state building code and the building classes defined in it. The thresholds differ between the federal states, which is covered in the article on German building regulations.

For apartment buildings, conversion between habitable area and gross floor area weighs more heavily than for detached houses. An evaluation of 223 residential buildings puts the habitable area share at an average of around 53 to 56 per cent of gross floor area, corresponding to a conversion factor of about 1.80 to 1.90.

By comparison, for a detached house without a cellar the factor sits at about 1.40. The difference is accounted for by stairwells, lift shafts, storage compartments, plant rooms, bicycle stores and underground parking, all of which enter gross floor area in full.

In practice this means a figure in euros per square metre of habitable area sits arithmetically almost twice as high for an apartment building as the same situation in euros per square metre of gross floor area. Placing a benchmark from a professional dataset, which works in gross floor area, beside a market figure working in habitable area produces an apparent difference of around 80 per cent arising entirely from the reference area. The system is set out in the article on reference areas.

Storey count. As the number of storeys rises, cost per square metre initially falls, because foundations, roof and circulation core spread across more floor area. Above certain thresholds the effect partly reverses: higher building classes bring stricter requirements for fire resistance, escape routes and lifts, and above the high-rise threshold a fundamentally different regime applies. For conventional multi-storey housing the economic optimum sits at middling storey counts.

Unit size. Small dwellings cost more per square metre, because bathroom, kitchen, entrance door, meters and connections arise per dwelling rather than per square metre. A building with many small units therefore carries a noticeably higher benchmark than a building of the same area with few large ones. On micro-apartment schemes this effect is the dominant cost driver.

In multi-storey housing the area benchmark alone is not enough. A second measure, cost per dwelling, captures precisely what the area benchmark does not show.

The reason is the cost structure: a substantial part of building cost arises per dwelling rather than per square metre. That includes the bathroom, kitchen connections, entrance door, consumer unit, meters, entry phone and a share of the circulation. Two buildings of identical area, one containing twelve dwellings and the other twenty, differ considerably on these items.

In practice it is therefore worth carrying both benchmarks in parallel at early stages. One serves marketing, the other cost control.

Where the two results diverge sharply, the cause is almost always an unusual unit mix. That is not an error but a signal, and the cost estimate should make it visible.

A growing share of German housing arises not on open sites but by adding storeys to existing buildings or by infill development. New build benchmarks do not transfer to this work.

Costs run lower because site, servicing and in part foundations fall away. They run higher because the existing structure must be assessed and frequently strengthened, because work proceeds in occupied buildings, because site establishment and material transport are more demanding, and because fire safety must be reassessed for the building as a whole. A lift retrofit is regularly added once the additional storeys cross a threshold in the state building code.

Dispersion on such schemes is markedly wider than in new build, because a substantial part of the cost only becomes known once the fabric is opened up. The framework for work on existing buildings is covered in the branch on renovation costs per m².

A study of production costs in new residential construction puts the average for German major cities in the fourth quarter of 2024 at around 4,473 euros per square metre, against around 3,028 euros in 2020. That is a rise of nearly 50 per cent in five years.

These figures are valuable for reading the market, but their scope needs checking before use: production costs in that system are not congruent with the building cost of cost groups 300 and 400. What they establish above all is that benchmarks predating 2021 have become unusable without updating.

• Residential construction costs in Germany
• Detached house construction costs per m² of gross floor area
• Reference areas: BGF, NRF and Wohnfläche
• Regional construction cost differences in Germany
• Construction costs per m² in Germany