Additional Certification & Testing

For certain new buildings, conversions and extensions, the Building Regulations requires testing and certification to be provided to demonstrate compliance. County Building Control will make you aware of the requirements relating to your individual project during the ‘plan check’ stage – but typical examples are shown below.

SAP calculations for dwellings

SAP Calculations are a requirement of the Building Regulations, and are required for all newly built dwellings in the UK. SAP stands for ‘Standard Assessment Procedure’. It is the only official, government approved system for assessing the energy rating for a new home. SAP assessors must be accredited and registered with a certification body.

SAP calculations are required for New Build Domestic Projects, Substantially Glazed Extensions and dwellings formed by Material Changes of Use. SAP determines the energy efficiency and CO2 emission rate of a dwelling and demonstrates compliance with Parts L1A and L1B of the Building Regulations 2010. An Energy Performance Certificate (EPC) is also issued at completion, based on the ‘as built’ SAP calculations.

Homes built after April 2014 in England are also assessed on Fabric Energy Efficiency. This is not a measure of carbon, but energy demand in units of kilowatt-hours per m2 per year. How well a home retains the heat it produces will have an impact on its CO2 emissions as well as being assessed separately to gauge compliance. Fabric Energy Efficiency is assessed using DFEE/TFEE figures. As with emissions the target is set within SAP using a set of baseline values depending on the size of the property.

SAP calculations for extensions

Building regs require that areas of new glazing should account for no more than 25% of new floor area, plus the area of existing openings covered by the proposals. Of course, many extension designs will propose more than this, and therefore will not comply against this rule. Glazing and openings lose more heat than walls and roofs, which is why the building regs set the 25% limit. However by upgrading or over compensating in construction of other elements, or perhaps demonstrating additional, useful solar gains by virtue of that extra glazing, the negative impact of larger expanses of glass can be removed. A SAP calculation can be used to demonstrate compliance and give greater flexibility on design and use of glazing to create additional natural light.

SBEM & EPC for Commercial Buildings

Commercial buildings also require the submission of CO2 emission calculations, but for buildings other than dwellings this is produced via the SBEM method/ software.

An SBEM (Simplified Building Energy Model) Calculation is required for all Commercial New Build Projects, Fit Out Work and Large Extensions.

SBEM determines the energy efficiency and CO2 emission rate of a commercial building and demonstrates compliance with Parts L2A and L2B of the Building Regulations 2010.

An Energy Performance Certificate (EPC) is issued at completion.


Water efficiency calculations

Building regulations demand that new dwellings meet the minimum 125 litres per-person-per-day water consumption limit, and planning departments also have powers to stipulate this must be further limited to 110 litre per-person-per-day. A water efficiency calculation is required to demonstrate how this will be achieved.

Pre completion sound testing

Building regulations Part E requires that buildings are to be tested prior to completion in order to determine the airborne sound insulation (speech, music) and impact sound insulation (footfall) standards that have been achieved between residential dwellings.

The person carrying out the building work should arrange for sound insulation testing to be carried out by a testing body with approved qualifications and affiliations. Failure in the test will result in the sound insulation needing to be improved and the construction type re-tested.

Ventilation testing

Part F of the Building Regs applies to ventilation requirements, and was updated in December 2010.Testing validates air flow measurements for the new dwelling and ensures that the system has been configured correctly. Testing should be carried out by a BPEC qualified engineer using UKAS calibrated equipment.The tests may be simple background and intermittent fans, or whole house mechanical extract systems with heat recovery.

Air pressure testing

Air tightness signifies the extent to which the building fabric enables either inward or outward uncontrolled air permeation. Testing is undertaken to determine a building’s air permeability rating, most commonly in order to demonstrate Part L compliance. Air leakage is a significant cause of heat loss, and is therefore a major contributor to energy inefficiency in buildings. For this reason, Part L of the Building Regulations requires new buildings to meet specific air permeability targets.

Regulation 9 of the Building (Approved Inspectors etc.) Regulations 2010 dictates that County Building Control must have no involvement in any aspect of design on projects where we are providing the Building Control function. County Building Control have an affiliate company agreement with Falcon Energy Ltd- Energy conservation specialists, who can provide additional designs, testing and certification when required. However, there is no obligation to use any particular company and County Building Control encourages architects, agents and owners to choose an engineer based on the specific needs of their project and services offered by the company.

Falcon Energy


Falcon Energy
Unit 12 First Floor
Foundry Lane
West Sussex
RH13 5PY

Tel/Fax 01403 253439