An Energy Performance Certificate (EPC) is a certificate which demonstrates the Asset Rating (AR) of a building. Their requirement for UK buildings has been driven by the adoption of the EU Energy Performance of Buildings Directive (EPBD). With over 40% of the UK’s energy consumption and carbon emissions produced by buildings and their construction, there are significant savings to be made.The energy performance of a building is identified using an ‘A’ to ‘G’ rating system, similar to the energy ratings provided with a fridge or washing machine. Services such as lighting, heating and ventilation) are taken into account as well as the way in which these services are controlled. An ‘A’ rating is the most efficient and a ‘G’ rating the least efficient with the energy performance of the building shown as a CO2 based index. A commercial EPC is accompanied by a secondary report providing recommendations on how the energy performance of the building can be enhanced, together with an indication of the payback period. These recommendations are provided in three categories relating to the payback period.
Since 4th January 2009, Energy Performance Certificates (EPCs) have been mandatory upon construction, sale or lease for all non-dwellings, covering everything from small retail units to offices, industrial units and large scale commercial premises such as airports, as well as public buildings. Responsibility for enforcement in newly built properties will fall to Building Control, whilst Trading Standards departments will enforce certification of existing buildings. Non compliance risks a fine of up to £5000.
The following types of building do not require an Energy Performance Certificate:
- Places of worship
- Stand-alone non-dwellings less than 50m²
- Temporary buildings with a planned life of less than two years
- Industrial premises with low energy use where the space is mostly not heated or cooled (such as process and heavy engineering workshops and agricultural stores)
- Buildings to be demolished within two years
A Commercial EPC (Energy Performance Certificate) is valid for 10 years or until a newer EPC is produced, and must be made available to a prospective purchaser or tenant at the earliest opportunity before entering a contract for sale or lease and no later than the release of marketing material or the request for a visit to the property. There is no requirement for a Commercial EPC for existing tenancies. The EPBD only affects newly built commercial properties, those being offered for sale/lease, or following certain very specific types of modifications to a building. Only accredited Energy Assessors qualified in assessing non domestic buildings can carry out the assessments and produce a commercial EPC.
There are three levels of commercial property energy assessment:
Level 3: This covers smaller existing properties with simple heating, lighting and ventilation systems. Many commercial properties will fall under a level 3 assessment requirement. A Simplified Building Energy Model (SBEM) is used to generate the EPC.
Level 4: Typically a larger building with more complex heating, lighting and ventilation. These buildings will often feature a centrally controlled zonal heating system(s) and air conditioning, for example. An SBEM is used to generate the EPC.
Level 5: At this level, the building might be a very large office block, hospital or university campus with complex heating, lighting and ventilation systems, controlled by a building energy management system. A Dynamic Simulation Model (DSM) is used to generate the EPC.
In order to produce a Commercial EPC it is normally necessary for the assessor to visit the premises, and understand the internal layout of the building and for what purposes it is designed to be used. This is to understand the energy demands of each individual space (zone) in accordance with its designed use. Dimensions of the building are required either as verified from plans or as measured, in addition to
- heating and ventilation services for each zone (including type of system, metering, controls, fuel used etc.)
- lighting and controls used for each zone, and
- the construction of the fabric of the building and thermal efficiency of the materials used (roof, floors, walls, glazing)
If there are no plans for a building, the energy assessor will need to survey the building and gather the appropriate information. If there are up-to-date information and plans for the building this process will be less time consuming.
This information is used as inputs to SBEM or DSM software to produce the EPC and recommendation report.
The CO2 based rating a building receives depends on the energy used for space heating, water heating, ventilation and lighting, less any energy generated from energy generation technology installed in the building. The lower the number (on a scale of 0 to 150+), the lower the typical CO2 emissions. The rating is adjusted for the total useful floor area of a building so it is independent of size for a given type of building. Once completed, documentation can be sent via email as a .pdf document and/or in hard copy.
Due to the individual nature of Commercial EPC assessment, it is unlikely to be possible to give an estimate of cost without a site visit, in all but the simplest of cases. The vast majority of enquiries will be quoted after a meeting on site to establish size, complexity and information available.
Given the amount of information required, a lack of the any of that listed above will lead to a greater information gathering commitment for the energy assessor and will increase the cost. Conversely, where multiple EPCs are required at one site, economies of scale can be negotiated where a single or reduced number of visits are applicable.