The energy certificate: duties, deadlines and what buyers should read

Anyone selling or letting a property must present prospective buyers with a valid energy certificate no later than the viewing — unprompted. The listing itself must already state the certificate type, the energy figure, the main energy source, the year of construction and the efficiency class. Omit them and you risk a fine.

Demand-based or consumption-based?

The consumption certificate looks backwards: it takes the last three years of heating bills and derives a figure. Cheap and quick — but it says more about the previous occupants than about the building. A frugal single person in a large house produces a flattering number.

The demand certificate looks forwards: a specialist surveys the building fabric, insulation, windows and plant, and calculates theoretical demand under standardised use. More effort and more expensive, but independent of occupant behaviour and therefore the more honest figure for a buyer.

For residential buildings with up to four units whose building application predates 1 November 1977 and which have not since been brought up to the thermal standard of that time, the demand certificate is mandatory. Otherwise you may choose.

Valid for ten years

An energy certificate is valid for ten years from issue. After that a new one is needed — assuming the building is to be sold or let. Purely owner-occupied use carries no obligation. After a thorough renovation a new certificate is worth having anyway: it documents the improvement and shows up immediately in the listing.

What buyers should actually read

The efficiency class from A+ to H is a guide, not a verdict. Three details together tell you far more:

• the energy source — a 2010 gas boiler has a different replacement horizon than a heat pump
• the age of the plant, which is recorded in the certificate
• the modernisation recommendations on the last page, routinely skipped, which carry the most concrete indication of costs ahead

A poor class is not a deal-breaker but a pricing argument — provided you know what the upgrade costs. That is precisely the calculation we work through with you before you make an offer.