Comunidad de propietarios
The legally-mandated homeowners' association every apartment building has under Spanish law (Ley de Propiedad Horizontal).
The comunidad de propietarios is the homeowners' association every Spanish apartment building automatically has under the Ley de Propiedad Horizontal (the Horizontal Property Law). All apartment owners are members by virtue of ownership; you cannot opt out.
The comunidad manages common areas — the lobby, lift, pool, garden, rooftop, façade, communal lighting — and collectively pays for maintenance, building insurance for the structure, administrator fees, and any voted-on improvements. It is funded by monthly fees from all owners, calculated based on each apartment's cuota de participación (participation coefficient), which is recorded in the property deed.
Decisions are made at the annual junta (general meeting), where each owner has voting rights proportional to their cuota. A president is elected from the owner group, and a professional administrator (administrador de fincas) is typically engaged to handle day-to-day operations.
When buying, request the last two AGM minutes (actas), the current budget, the reserve fund balance, and any derramas (special levies) voted in the last 24 months. The comunidad's financial health and culture is part of what you're buying — sometimes the most important part.