How much does it cost to renovate an old house and which mistakes make it more expensive

The question how much does it cost to renovate an old house appears when the building condition is uncertain. In these cases, priorities should be technical first, not aesthetic.

If structure, roof, or damp issues are not diagnosed early, the budget becomes unreliable and site risk increases.

Overruns often come from unplanned demolitions, on-site system changes, and late layout decisions.

Unexpected issues in foundations, slabs, and construction junctions are also common in older buildings.

Start with diagnosis, then intervention strategy, then itemized budget, and finally tendering with closed scope.

At BAU, we apply this sequence in old-house renovations to balance technical feasibility, spatial quality, and financial control.