Starting July 20, 2013, homeowners must present potential buyers or tenants with the building’s energy certificate before the transaction is completed, otherwise the contract is considered void, Alexandru Petrescu, managing partner of real estate consulting company Esop Consulting, said Wednesday.

The measure is stated in Law 159/2013, which was published in the Official Journal last week and amends Law 372/2005 on energy efficiency in buildings.

The measure should have been applied starting 2010 but was put off several times as notaries argued it would lead to a 5%-10% increase in old home prices, which would freeze transactions. Also, the Government said the norms to apply the new system were not clear enough and the number of energy auditors was scarce.