According to the law 4178/2013 it is prohibited and it is invalid any property contract transfer, without an engineer’s certificate, that confirms that the property is legal & has been build according to its building permit & the related legal plans. In the case that there is any construction beyond the permit limits, it is necessary to be "legalised" by an engineer & all the related documents along with the engineer’s certificate must be attached in the contract.

The certificate does not include the check of common use surfaces of the property.