Terrace and roof terrace renovation

A terrace attached to a flat is very frequently not private property in the way the estate agent implied, and foreign buyers are rarely told before completing.

Private use of a communal element

Most roof terraces and many first-floor terraces in Barcelona are elementos comunes de uso privativo — communal elements assigned to your exclusive use. You use it alone, nobody else may go on it, but the structure and the waterproofing below it belong to the building. The practical consequence is the one that costs money: maintenance of the surface you walk on is normally yours, while the structural deck and the waterproofing layer are the comunidad de propietarios’ responsibility, funded by a derrama split by coeficiente de participación. Where the boundary sits is written in the deeds and the building’s statutes, not decided by common sense, and it is the first thing we read before quoting.

Why this matters before you spend anything

Rebuild it privately when it is the building’s and you have paid for something the association would have funded. Lay expensive paving over a membrane it later has to renew and your paving comes up. For an owner abroad, settling that boundary is a written exchange with the administrator, not a conversation on the stairs.

A leak downstairs is not a private matter

When water reaches the flat below, the neighbour claims. If the failure is in the waterproofing and the waterproofing is communal, it goes to the building’s insurance and the association. If it is in work you had done, it is yours, and an unauthorised alteration weakens your position considerably.

Glazing it in is the most expensive mistake

Enclosing a terrace usually creates additional built floor area. That means a licence, a technical project, a change to the registered description of the flat and — because the appearance of the building changes — authorisation from the junta. Owners who did it without permission discover it at sale, when the buyer’s lawyer stops. Undoing it costs more than doing it properly. We check what the planning rules and the statutes allow before drawing anything.

Documents you get, being remote

• Photographs of the stripped deck before the new membrane goes down
• The flood test recorded with the date and the result
• Written confirmation from the administrator where any communal element is touched
• Falls and outlet positions marked on a drawing, not agreed verbally on site