Approved document L
To help develop this article, click 'Edit this article' above.
The Building Regulations set out requirements for specific aspects of building design and construction. Regulation 26 of the building regulations states that “Where a building is erected, it shall not exceed the target CO2 emission rate for the building…”, and Schedule 1 – Part L Conservation of fuel and power states that provision for conservation of fuel and power shall be made by: limiting heat gain and losses and providing building service which are efficient, have effective controls and are properly commissioned and that information is provided so that the building can be operated efficiently.
A series of approved documents provide general guidance on how different aspects of building design and construction can comply with the Building Regulations.Approved Document L: Conservation of fuel and power, deals with energy efficiency requirements.
There are four parts to Approved Document L:
- Approved Document L1A: Conservation of fuel and power (New dwellings).
- Approved Document L1B: Conservation of fuel and power (Existing dwellings).
- Approved Document L2A: Conservation of fuel and power (New buildings other than dwellings).
- Approved Document L2B: Conservation of fuel and power (Existing buildings other than dwellings).
Key criterion described in Approved Document L include:
- The designed carbon emission rate (Dwelling Emission Rate (DER) for self-contained dwellings and individual flats (excluding common areas) and Building Emission Rate (BER) for buildings other than dwellings) must not exceed the Target Emission Rate (TER) for a notional building of similar type, size and shape. Both are expressed in kgCO2/m2 per year.
- Fixed building services should achieve a reasonable standard of energy efficiency. This is intended to prevent inappropriate trade-offs between different elements of the building. Minimum limiting parameters are set for key components of the building fabric to ensure that this is the case.
- Solar gains should be limited.
- As-built performance should be consistent with the DER. This includes air-permeability testing and appropriate commissioning of building services systems.
- Provision should be made for energy efficient operation by providing the building owner with information enabling them to operate the building in a way that uses no more fuel and power than is reasonable. This might be done by the preparation of a building log book.
- Limiting fabric parameters.
Within 5 days of the completion of the construction, a report must be issued to the BCB setting out the TER, BER or DER, any changes that have been made to the specification, and an energy performance certificate (EPC). These calculations require that an air-permeability test is carried out to ensure that the building envelope has been constructed to a suitably high level of workmanship so that air (and so heat) will not 'leak' through the building fabric. In addition, the BCB is likely to require a commissioning notice.
For buildings other than dwellings, the TER and BER can be calculated and the EPC produced by following the National Calculation Method (NCM). This can be done by using approved simulation software (Approved Dynamic Simulation Models (DSMs)) or by using the Simplified Building Energy Model (SBEM), a 'simplified' compliance tool developed by BRE, which has a user interface called iSBEM.
 2013 changes
The approved documents were upgraded on 6 April 2014, with a 6% increase in performance standards for new dwellings and 9% for non-domestic buildings. See 2013 changes to the approved documents for part L of the building regulations for more information.
The 2013 edition of approved document L1A for new dwellings, introduced Target Fabric Energy Efficiency rates (TFEE) to sit alongside Target Emission Rates. The TFEE is the minimum energy performance requirement for a new dwelling. The Dwelling Fabric Energy Efficiency (DFEE) rate is the actual energy performance of the new dwelling. The DFEE must not exceed the TFEE. See Target fabric energy efficiency rate for more information.
 Related articles on Designing Buildings Wiki
- 2013 changes to the approved documents for part L of the building regulations.
- Accredited construction details ACDs.
- Air permeability testing.
- Air tightness.
- Approved documents.
- Building emission rate.
- Building Research Establishment.
- Building log book.
- Building regulations.
- Controlled fitting.
- Conventions for U-value calculations (2006 edition) BR 443.
- Dwelling emission rate.
- Dwelling fabric energy efficiency rate
- Energy performance certificate.
- Energy targets.
- Floor insulation.
- Lighting energy numeric indicator.
- Limiting fabric parameters.
- National Calculation Method.
- Non-domestic building services compliance guide.
- Roof insulation.
- Simplified Building Energy Model.
- Standard Assessment Procedure.
- Target emission rate.
- Target fabric energy efficiency rate.
- Zero carbon homes.
- Zero carbon non-domestic buildings.
 External references
- Planning portal: Approved document L
Featured articles and news
What will the General Data Protection Regulations (GDPR) mean for you when they come into force in May?
Business Secretary chairs a new taskforce to monitor and advise on mitigating the impacts of Carillion’s liquidation.
Sir John Armitt is appointed the new chair of the National Infrastructure Commission.
High quality and high density homes - is it what we need or is it storing up trouble?
Government announces its intention to strengthen planning rules to protect music venues and neighbours.
National Audit Office reports that there is little evidence that PFI offers better value than other forms of contracting.
What is liquidation and how does it apply to contractors in the construction industry?
Scrutiny is placed on Carillion's controversial 2013 decision to extend subcontractor payment terms to 120 days.
RSHP unveil their involvement in a boundary crossing which will provide a new entry point into Hong Kong.
With PFI currently under the spotlight due to Carillion, this introductory article explains what they are.
Estimates suggest that up to 30,000 small firms could be at risk of non-payment as a result of Carillion's collapse.