The cost bands
| Configuration | Shell per m2 | Current finished level per m2 |
|---|---|---|
| Two-storey block (4-6 units) | EUR 750 - 950 | EUR 1,300 - 1,700 |
| Three to four storeys (8-12 units) | EUR 700 - 900 | EUR 1,200 - 1,600 |
| Reference: detached house | EUR 800 - 1,000 | EUR 1,600 - 2,000 |
At equal finish level, multi-unit construction costs 15-25 per cent less per m2 than a detached house. The decline is not linear: it grows with the number of floors while the structural economies dominate, then fades when additional requirements kick in (mandatory lift, fire prevention above height thresholds, second staircases). For the small developer, the most efficient configuration is often the one just below a regulatory threshold.
Where the economies of scale come from
Foundations and roof spread out. These are the most expensive blocks per m2 of footprint: in a three-storey building they are divided by three habitable floors instead of one.
Services that can be centralised and repeated. Common risers, heat metering, bathrooms stacked floor on floor: vertical repetition is the cheapest form of building services.
A more efficient site. A crane serving 900 m2 amortises its hire better than one serving 120; crews repeat the same trades floor after floor with real learning curves.
The items a detached house never meets
| Item | Order of magnitude | Note |
|---|---|---|
| Stair core and lift | EUR 60,000 - 120,000 lump sum | The lift weighs more on small blocks than on large ones |
| Common areas (entrance, cellars, lighting) | 3 - 6% of cost | Built area that cannot be sold as habitable |
| Fire prevention | grows with height | Above regulatory thresholds, equipment and filings kick in |
| Acoustic insulation between units | 2 - 4% of cost | Requirements between dwellings far stricter than within a house |
| External works and parking | variable | Planning parking standards to be checked immediately |
The acoustic item deserves emphasis: it is the most contested defect of multi-unit buildings at handover, and correcting it afterwards is among the most expensive interventions in construction. Acoustic testing during the works costs little and prevents much.
Budget example: six-unit block, 620 m2 saleable
Three storeys above ground, current sale-grade finish level, medium-cost area. The example includes common parts and external works.
| Item | Calculation | Amount |
|---|---|---|
| Construction cost | 620 m2 × EUR 1,450 | EUR 899,000 |
| Professional fees (design, structures, supervision, safety, ~11%) | EUR 98,900 | |
| Urbanisation fees and building contribution (estimate) | EUR 55,000 | |
| Connections and site utilities | EUR 15,000 | |
| Contingencies (8%) | EUR 71,900 | |
| Total excluding land | EUR 1,139,800 | |
| Per unit (average) | / 6 | ~EUR 190,000 |
The per-unit reading is what matters to whoever sells: to the technical cost of ~EUR 190,000 per dwelling must be added land, finance costs and marketing to reach the full cost to compare against local market values. That is the comparison that decides whether the operation stands up, before any site optimisation.
The small developer's point of view
Three recurring rules separate successful operations from painful ones. The plot is bought with the numbers done: saleable value in the area, estimated technical cost, target margin; if the arithmetic only works on optimistic assumptions, it is the land price that must come down. The sales specification is written early: defining finishes and variants before signing on the drawings avoids the spiral of on-site customisations, which destroy programme and margins. Regulatory thresholds are mapped at feasibility stage: fire safety heights, lift obligation, parking standards; each moves the cost in steps, not linearly.
Note: the figures shown are 2026 orders of magnitude for the Italian market, for guidance only. Every project requires a specific estimate based on a bill of quantities and up-to-date regional price books.