Producing DECs

An energy assessor, accredited to produce DECs, is the only person who can produce a DEC and advisory report for your building. It is acceptable for employees to produce DECs provided they meet the standards of and are accepted by an accreditation scheme.

Firstly the energy consumption data provided will be reviewed by the energy assessor in line with the approved methodology. Under certain conditions, the methodology allows adjustments to be made for longer hours of occupation, variations to weather and climate and allows certain activities to be separated if they are not typical of the type of building (separable energy uses).

The carbon dioxide emissions for the certificate are based on the adjusted energy consumption and adjusted total useful floor area and building type to give a measured CO₂ emission per square metre.

The energy assessor will then use an approved tool to calculate the operational rating and produce a DEC and advisory report from the information gathered in line with the approved methodology.

To produce the first DEC and advisory report, the energy assessor must visit the site. In subsequent years the DEC and advisory report can be based on previous knowledge of the building, provided that:

• they are being produced by the same assessor; and
• a declaration that nothing has changed has been provided by the building occupant

The DEC and advisory report must be lodged on the national register and given a unique certificate reference number.

Energy assessors must act in an independent manner – this is ensured by their membership of an approved accreditation scheme. Energy assessors are responsible for conducting an energy assessment, producing a DEC and advisory report and lodging the DEC and advisory report with their accreditation scheme.

The accreditation scheme is responsible for checking and lodging certificates on the national register. Accreditation schemes are also responsible for monitoring the quality of the certificates energy assessors produce.

Once an energy assessor has been commissioned to produce a DEC and advisory report, there are 3 main steps to performing the assessment, which are:

• gathering the relevant information (dimensions, energy meter readings and building energy services)
• entering the information into an approved software (operational rating methodology) program
• the software producing the certificate and the advisory report for the building

The energy assessor then submits the certificate and advisory report to their accreditation body for lodgement on the government’s register and provides the building occupier with a copy.