Why legalising matters
An unlicensed building can complicate a sale, a mortgage, an insurance policy or a holiday-let registration. In some cases it can also lead to fines.
Is it always possible?
No. Legalisation is only possible if the building can comply with the current planning rules, sometimes with adaptations. That is why the first step is always a feasibility analysis.
The usual steps
Gathering documents (tax registration certificate, land registry certificate, previous permits); an accurate survey of what exists; feasibility analysis; a legalisation project with the required engineering; submission and follow-up with the Municipality; and issue of the occupancy permit.
A final tip
If you are thinking of selling or buying a house with annexes or extensions, check its status before you sign. A preliminary analysis can save many months and a lot of money.