Cracks in three of 21 wooden beams were found during routine inspections but more work is needed to find the source of the problem, causing the administration to temporarily close part of the building, a statement said.
“The parliament has decided to take strong measures as a matter of precaution and prevention,” said spokesman Jaume Duch.
The parliament’s next plenary is scheduled to take place from September 10 to 13 in its other home in the French city Strasbourg.
The partial closure “is a fantastic metaphor for the structural weaknesses of the EU,” said British eurosceptic MEP Nigel Farage.
“It is running out of popular support, the European Union and euro are both showing cracks.