England, Wales & Northern Ireland
The validity of a Display Energy Certificate (DEC) and Advisory Report (AR) depend upon the floor area of the building. For buildings with a floor area greater than 1000m2, the DEC is currently valid for one year and the AR for up to seven years.
For buildings with a floor area greater than 250m2 but less than 1000m2, both the DEC and AR are currently valid for up to ten years.
However, significant changes to the occupation of the building or its floor area may require a new DEC or AR. As the DEC relates to the occupier not the building, a change in occupier will require a new DEC.
There is no requirement to have an AR in Scotland and so a validity period is not relevant in this context.