S.L. 623.1 ст. 8Existing buildings.

(1) When buildings undergo major renovation, in order to ensure that the renovated part thereof is upgraded to meet the minimum energy performance requirements in force at the time, the owner has to provide to the Building and Construction Authority a compliance certificate drawn up by a warranted architect (perit) or engineer or both, as the case may be, certifying such compliance, within one month of completion of works and before the use of the building.

(2) means technical equipment for space heating, space cooling, ventilation, domestic hot water, built-in lighting, building automation and control, on-site electricity generation, or a combination thereof, including those systems using energy from renewable sources, of a building or building unit;

(3) When a building element that forms part of the building envelope which is -

(a) greater than 10% of the whole building envelope area in case of opaque elements; or

(b) greater than 5% of the whole building envelope area in case of glazed elements, and is retro-fitted or replaced, in order to ensure that it meets the minimum energy performance requirements, the owner has to provide to the Building and Construction Authority a compliance certificate by a warranted architect (perit) certifying such compliance within one month of completion of works and before the use of the building.