The Institute for Energy and Transport (IET) is one of the 7 institutes for scientific research of the Joint Research Centre (JRC), a Directorate-General of the European Commission (EC). 3 of the IET's buildings (Nos 308, 309 and 312) have been leaking for some time. An architectural survey has discovered that there are some architectural defects which, in conjunction with the necessary maintenance, can cause serious leaks. This invitation to tender includes carrying out maintenance and adjusting architectural defects on Building Nos 308, 309 and 312.