How long does a home renovation take?
For an apartment of around 100 m², design takes 6–10 weeks and construction a further 4–6 months. Of that, 8–10 weeks is the lead time on bespoke joinery — which is ordered at the end of the design phase, not at the start of construction.
Krizbai András · Last verified: August 2026
| Stage | Duration (around 100 m²) |
|---|---|
| Design | 6–10 weeks |
| Bespoke joinery lead time | 8–10 weeks, starting at the end of design |
| Construction | 4–6 months |
Bespoke joinery is the critical path in a renovation programme. If the joinery order slips to the start of construction, those 8–10 weeks do not absorb into the build — they add to it: services complete, no kitchen. This is why joinery production drawings are finished at the end of the design phase, and why the order goes out when the drawings are approved.
Design time is not lost time
There is an old joke: three months of design and six months of construction, or six months of design and three months of construction — you end up in the same place. Just not for the same money.
At the level where a client pays EUR 70 per square metre for design, every hour spent designing is shift-left problem solving. The mistake is the same mistake either way; what differs is where it surfaces. A badly placed service shaft on a drawing costs an afternoon. The same mistake on site costs demolition, new material, delay and a contractor's goodwill. The design phase is long because that is where errors are cheap.
There is a limit to this. A design cannot be finished, only stopped. There is always one more version that is better in some respect. So the finish line is not “complete” — it is the design freeze: the stated point beyond which the design does not change and from which procurement begins.
Design freeze needs the client too
A design freeze — the point at which the documentation is approved for production — is a shared achievement, not a designer's decision. It asks two things of the client.
First, to let go of things at the right moment and at the right point. Timing matters: everything is open during concept, progressively less during design development, and nothing after freeze — not out of rigidity, but because orders are running by then.
Second, to say so honestly when something is not understood. If a drawing or a decision is not clear, it gets explained until it is unambiguous. Unspoken uncertainty does not go away; it reappears on site, when the wall is already up.
Why this takes time: few people can read a drawing
A professional observation rather than measured data: the great majority of people cannot read construction drawings and cannot sense space from a plan. That includes architects and interior designers. It is not a shortcoming but how spatial perception works — a two-dimensional projection is not a space.
This is why visualisations, the digital twin and a walkable model are not vanity. They exist so that what is coming is visible before the decision is taken — because the purpose of the design phase in Ren Design practice is to bring every problem to the surface while it is still on paper. That takes time, and a project either spends that time at the front or pays for it at the back.
When programming a renovation, avoid these: ordering bespoke joinery at the start of construction; starting on site without a design freeze; shortening the design phase on the grounds that “we'll decide it on site”; and approving a drawing the client does not understand.
The durations above are indicative figures from Budapest practice for a full renovation of around 100 m². Actual programme depends on scope, permitting and contractor availability.
A project either spends design time at the front or pays for it at the back. What an interior design project costs → · How we work →