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Energy efficiency in commercial buildings

Energy performance certificates: What, when and why?

Energy Performance Certificates


An energy performance certificate (or EPC) is a certificate containing information on the energy efficiency of a building.  It is produced by a qualified “energy assessor” who inspects the building and measures its floor space, the type of construction, energy saving features, heating and air cooling systems.

The certificate contains an “asset rating” ranging from A to G with A being the most efficient and G being the least efficient.  It also contains a “recommendation report” listing suggestions for the improvement of the energy performance of the building including cost-effective alterations and measures that will require a higher level of expenditure.


When a building is sold or let out the seller or landlord must provide a copy of the EPC free of charge to the buyer or tenant.  The obligation is triggered on the first of the following to occur:

  • the seller/landlord provides written information about the building to the person who has requested it
  • a prospective buyer/tenant views the building
  • a contract is entered into for the sale or letting of the building

When a building is erected or converted the EPC must be provided before the building inspector will issue the building regulations completion certificate.

But EPCs are not required for:

  • lease renewals, extensions or surrenders
  • the sale of shares in a company where the building remains in the ownership of the company
  • places of worship
  • temporary buildings with a planned use of 2 years or less
  • buildings which accommodate industrial activities in spaces which are not heated or cooled – eg warehouses and storage depots
  • agricultural buildings with low energy demand (ie only require heating on a few days a year)
  • stand alone buildings with a useful floor area of less than 50 sq m (approximately 540 sq ft)
  • off-plan sales or lettings of newly erected or converted commercial buildings


The EPC requirements have been phased in as follows:

  • Buildings over 10,000 sq m (107,639 sq ft)  –  6th April 2008
  • Buildings over 2,500 sq m (26,909 sq ft)  –  1st July 2008
  • All buildings  –  1st October 2008  


EPCs allow potential buyers or tenants to assess the energy efficiency of a building and the recommendation reports provide the occupier with advice on how to make improvements to the energy performance of a building.

The building sector accounts for approximately 40% of the EU’s total energy consumption and 50% of the UK’s total carbon dioxide emissions.  The European Commission passed the “Energy Performance of Buildings Directive” in 2002 which aimed to promote improved energy efficiency in both residential and commercial buildings in the EU.  The UK Government had to implement the EPB Directive by 4 January 2006 and then had  a further 3 years to bring it into force.  The Government has implemented the Directive in two stages:

  • Building and Approved Inspectors (Amendment) Regulations 2006.  These amended the Building Regulations 2000 to impose more stringent minimum energy performance requirements in buildings
  • Energy Performance of Buildings (Certificates and Inspections) (England and Wales) Regulations 2007.  These introduced the requirement for energy certificates and the inspection of air conditioning systems

Failure to comply with the EPC regime can result in a fine of between £500 and £5,000.

Display Energy Certificates

DECs are required for buildings with a useful floor area of over 1,000 sq m (10,763 sq ft) occupied by public authorities and institutions (central and local government, NHS trusts, schools, police, courts, prisons, MOD, army, executive agencies and statutory executive bodies) providing public services to a large number of persons and which are therefore frequently visited by those persons (schools, leisure centres – but not private clubs – hospitals, municipal golf clubhouses, public libraries, museums and art galleries).

A DEC is similar to an EPC but in addition to the information reviewed for an EPC, the energy assessor when preparing a DEC looks at the actual energy consumption of the building during its use by taking meter readings.

It is suggested that it in addition to public authorities and institutions who are obliged to display DECs, companies may want to commission DECs in order to analyse the energy efficiency of and energy consumption at buildings they occupy in order to both reduce their energy costs and improve their corporate social responsibility profile.

Inspection of air conditioning systems

The EPB Regulations 2007 impose an obligation on those who have control of air conditioning systems to ensure that the system is inspected at least every 5 years.  Following inspection the energy assessor must produce a report which will include an assessment of the efficiency of the system and the size of the system compared to the air cooling requirements of the building as well as advice on possible improvements.

For systems of any size installed after 1 January 2008 the first inspection must be carried out within 5 years of the system being put into service.

For systems installed before 1 January 2008, the first inspection for systems of more than 250kW must be carried out by 4 January 2009 and for systems of more than 12kW the first inspection must be carried out by 4 January 2011.