A commercial Energy Performance Certificate is required when a building is offered for sale or to let, and it should be available for when written information about a building is requested by a prospective buyer or tenant, or when a building is viewed by a buyer or tenant.
In any event, an EPC must be obtained before a contract for sale or to let is entered into by the parties.
Commercial properties are categorised for EPC assessment by qualified assessor's according to the buildings level of complexity served by their fixed service systems of heating, cooling and mechanical ventilation.
The types of commercial buildings that require having an EPC range from newly constructed to existing retail units, offices and industrial buildings to very large scale buildings such as out of town shopping malls and airports. Existing commercial buildings naturally ventilated with heating systems around 100kw output and with localised comfort cooling at around 12kw are the most common category and account for around 70% of the commercial building types in the UK.
A commercial EPC is required by law on the Construction, sale or lease of a building.
For the purpose of clarity of the regulations, a building is defined as: "a roofed construction having walls for which energy is used to condition the indoor climate and a reference to a building includes a reference to any part of a building which has been designed to be used separately".
A commercial EPC assessment is quite different to that of a residential property.
A commercial EPC assessment differs to a residential one by the wider scope of information required to be collected about the building, and the time required for the data to be inputted into the SBEM software that produces the EPC and accompanying recommendations report for the building.
On a residential assessment only the external perimeter walls and construction type are noted and measured, with also the floor and roof types also recorded. During a commercial assessment however, all building elements of external and internal wall constructions, floors, ceilings and roofs are recorded and their areas measured, external windows and access doors are also recorded and measured.
The overall building is then internally divided into separate zones for data collection and calculation purposes, these zones are determined by the activity within them and by the level of natural daylight entering them and also the type of fixed heating, cooling, ventilation and electrical lighting serving the zones.
With many existing buildings there may not be any current building plans or a log book with details of any history of fixed services and the lighting types within the building. In these cases a full detailed building inspection will need to be carried out and also floor plan drawings of the building completed.
The computer software program used to calculate the energy efficiency and carbon emission rating of a building is called the Simplified Building Energy Model (SBEM). This calculation methodology is also used for checking for Building Regulation Part L compliance purposes.
The Energy Performance Certificate records how energy efficient a building is and provides this on a A to G rating scale.

The energy performance of a building is shown as a carbon dioxide (CO2) based index rating. These ratings are produced using standards, methods and assumptions about energy use so that the energy of one building can be compared with another building of the same type.
Two other comparision ratings are also given which shows a rating if the building was newly built to current regulations and also that of a similar building of the same type.
The EPC is always accompanied by a recommendations report that details cost effective and other improvement measures to help reduce energy costs and carbon emissions of a building.
The EPC and recommendation report allows prospective buyers and tenants to see information about the energy efficiency and carbon emission levels of a building so that they can consider this as part of their interest in a building and their investment decision to purchase or occupy the building.
A commercial EPC when lodged on the National Register is valid for 10 years or until replaced by a newer one.
Display Energy Certificates...
Since October 2008 occupiers of public buildings with floor areas of more than 1000m2 (approx 10 000 sq ft), have been required to have a Display Energy Certificate (DEC).
It is the responsibility of the occupier of the building and not the building owner to ensure that a valid DEC is commissioned for the building and they will be liable for any penalty fines for failure to display the certificate.
The penalty for failure to display a DEC is £500 and a further £1000 for failing to obtain an Advisory Report. The legislation is enforceable by every Local Weights and Measures Authority.
DECs were introduced to raise public awareness of energy use by displaying the actual energy use and energy efficiency of the buildings they visit. This is based on records of gas, electricity and other meter readings or fuel delivery records in the case of oil or solid fuel.
DECs include an A-G energy rating for the building, where A has the lowest carbon emissions (best) and G the highest carbon emissions (worst). The certificate is similar to those that are required for fridges and many other new white goods.

The rating is also shown as a number. A typical building of its type would have a rating of 100 and a building with twice the typical carbon emissions would have a rating of 200 (or G). The DEC rating shows whether the occupier is using energy well or badly and performance over the last three years.
All buildings over 1000m2 mts in floor area require a certificate, and fuel consumption can be apportioned based on floor area where there are not separate meters on individual buildings. A copy must be displayed in each qualifying building.
The DEC should be clearly displayed at all times in a prominent place clearly visible to the public. A DEC is accompanied by an Advisory Report which lasts for 7 years, but does not need to be displayed and lists effective measures to improve the energy rating of the building. DECs are valid for one year, and therefore require updating annually.
The accompanying Advisory Report is valid for seven years. Both must be produced by an accredited DEC energy assessor.
How much will a DEC cost to produce?
The cost of a DEC certificate depends on information the occupier can make available to the assessor.
The occupier, in collaboration with the energy assessor, will need to know the floor area of the building being assessed and actual meter readings or consignment notes for all fuels used in the building over the period of one calendar year.
Where the building has accurate meter readings for the last 12 months up to the date of the certificate and reasonably accurate floor areas or plans from which they can be measured the cost should be relatively low.
Where estimates of fuel consumption have to be calculated because of incomplete or estimated fuel bills or floor areas need to be measured, then higher costs will be incurred.
Local IDEA
A Good IDEA For Local Independent Energy Assessment