What should you check before buying a flat in Badalona?

Sant Roc and Badalona's experience with aluminosis

In February 2003 the Catalan government signed an agreement with the four residents' associations of Sant Roc to speed up the rebuilding of the neighbourhood, one of several affected by structural defects such as aluminosis (the decay of concrete made with aluminous cement). The plan provided for 918 new homes and €60 million of public money to replace the existing blocks, in an area holding 5% of the city's homes.

The same press release mentioned similar schemes in Sant Cosme (El Prat), La Trinitat (Barcelona) and Arraona (Sabadell). In Badalona, then, aluminosis is part of the recent history of a specific neighbourhood, and it is worth asking about in any building of that era.

A public rebuilding scheme in one area says nothing about the building next door or in another district, though. The Barcelona building surveyors' association (CAATEEB) notes that joists from the 1950s and 1960s were made with both aluminous and Portland cement, often by the same factories, and only lab tests on samples show which one a floor has.

A later housing stock than Barcelona's

The decade with most homes in Badalona is the 1970s. The 2021 census counts 4,210 homes in buildings from 1951-1960, 24,486 from 1961-1970 and 31,115 from 1971-1980, so the end of that building cycle weighs more here than in the capital.

In practice, the CAATEEB places aluminous cement between 1950 and 1970. A block from 1975 falls outside that window, even if it shares other traits of its time such as poor insulation or original wiring and pipes. What counts is the exact year in the Catastro, Spain's register of buildings, not the decade. Another 23,376 homes are newer than 1980; there the focus moves to the energy certificate and the quality of later refurbishments.

A seafront city: flood exposure

Overlaying Badalona's boundary on the Spanish environment ministry's flood maps (SNCZI) gives 2 areas of potentially significant flood risk (ARPSI), and the first map layer that touches the city is the coastal one for a 100-year return period. Besides its streams, the coast has mapped flood zones.

If you look at a flat near the sea, what matters is the plot, not the city: the report overlays it on the river maps for 10, 100 and 500 years and the coastal maps for 100 and 500. An unmapped area is not proof of no risk, so for ground floors ask the community of owners about storms and water ingress.

Radon zone II: what it means and what it does not

Appendix B of the building code's health document (DB-HS6) places Badalona in zone II. There, new buildings and affected renovations must combine a gas barrier with an extra system: a ventilated containment space or ground depressurisation. The reference level is an annual average of 300 Bq/m³ in living spaces.

The zone describes the municipality, not your flat. A 1970s building went up without these rules, and radon mainly affects what is in contact with the ground: ground floors, semi-basements and homes over poorly ventilated crawl spaces. If you buy at that level, a measurement over several months is the only way to know the real concentration.

The inspection certificate and the sale

The Catalan Housing Agency requires every residential building to pass a building inspection (ITE) before it turns 45, using the Catastro year. In Badalona that covers any block from 1981 or earlier in 2026.

Depending on the defects, the certificate of fitness lasts 10 years (none or minor), 6 (significant) or 3 (serious or very serious, with safety measures done); without those measures it is refused. The seller must hand it over. Also ask for the full technical report and the community minutes, which show approved façade or structural works and how they will be paid.

What the HOUSINGFAX report tells you in Badalona

All 22 checks work for any address in the city. Check 03 gives the aluminosis risk level from the Catastro year; 10 looks at the plot on river and coastal flood maps; 22 records radon zone II; 07 compares the price with the housing ministry's average appraised value, €2,898.8/m² in the first quarter of 2026, 14.9% up on a year earlier.

Limits worth knowing: we do not check the Catalan inspection register yet, so the building condition only appears if you upload the inspection PDF, and the energy certificate shows no data because we do not check the Catalan Energy Institute (ICAEN) register yet either. The report does not replace a technical inspection of the building. Start with the free report; the essential one costs €11 and the complete one €19.