- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 07 Feb 2018
Target fabric energy efficiency rate
Dwelling Fabric Energy Efficiency rates (DFEE) and Target Fabric Energy Efficiency rates (TFEE) were introduced by the 2013 edition of approved document L1A of the building regulations, 'Conservation of fuel and power in new dwellings', which came into force on 6 April 2014. The energy performance requirements of the 2013 edition have been strengthened to deliver a 6% carbon dioxide saving across the new homes build mix relative to the 2010 edition.
Dwelling Fabric Energy Efficiency rates and Target Fabric Energy Efficiency rates sit alongside the requirements for Target CO2 Emission Rates (TER) and Dwelling CO2 Emission Rates which were already part of the 2010 edition of the approved document.
The Target Fabric Energy Efficiency rate is the minimum energy performance requirement for a new dwelling approved by the Secretary of State in accordance with regulation 25 of the building regulations. It is expresses as the amount of energy demand in units of kilowatt-hours per square metre of floor area per year (kWh/(m^2.year).
The TFEE is derived from a notional dwelling of the same size and shape as the actual dwelling being constructed. A summary of the Part L 2013 notional dwelling is published in Table 4 of approved document L1A and the full detail is set out in the Standard Assessment Procedure (SAP 2012) Appendix R. However, following responses to the consultation on the 2013 changes, a further 15% is permitted to allow some design flexibility.
If the actual dwelling is constructed entirely to the notional dwelling specifications it will meet the fabric energy efficiency targets, however, the notional dwelling is not prescriptive and developers are free to vary the specification, provided that TFEE rate is achieved or bettered.
Before work starts, the builder must calculate the DFEE rate of the dwelling as designed, to demonstrate it is not greater than the TFEE rate. The builder must give this design-based calculation to the Building Control Body (BCB) along with a list of specifications used.
When work is complete, the builder must notify the BCB of the DFEE rate and TFEE rate, and whether the building was constructed in accordance with the list of specifications submitted to the BCB before work started. A list of any changes to the design-stage list of specifications must be given to the BCB.
For a building that contains more than one dwelling (such as a terrace of houses or an apartment block), average rates can be used. An average cannot be calculated across separate multiple buildings on a site.
To guard against poor performance of individual elements, limiting fabric values are retained in Table 2 of approved document L1A and limiting building services efficiencies are set out in the Domestic Building Services Compliance Guide.
 Find out more
 Related articles on Designing Buildings Wiki
- 2013 changes to the approved documents for part L of the building regulations.
- Approved document L.
- Approved documents.
- Building control body.
- Building Regulations.
- Dwelling emission rate.
- Limiting fabric parameters.
- Standard assessment procedure.
- Target emission rate.
 External references
This article contains public sector information licensed under the Open Government Licence v2.0 ref:
- Approved Document L1A, Conservation of fuel and power in new dwellings, 2013.
- DCLG circular New and amended Approved Documents and new Building Services Compliance Guides to support the energy efficiency requirements of the Building Regulations. 3 December 2013.
Featured articles and news
ICE responds to a transport consultation advising the government to make decisions enabling more inclusive cities.
BRE and Loughborough University complete first phase refurbishment of demonstration home.
How the risk of collapse of fibrous plaster ceilings is being addressed in theatres.
If you’re a great writer and have practical experience of the construction industry, it could be you.
Frustrated by long documents or technical jargon? Put off by sign-up forms or costs? Take this 5 min survey to help improve construction knowledge.
These are attached to land that is the subject of a planning permission, and used to compensate for negative impacts.
ICE Scotland launch its new report for a long-term, holistic approach to infrastructure planning and funding.
Building surveys provide a detailed evaluation of a property's condition and involve an extensive inspection.
Government announces additional £2m funding for councils to tackle rogue landlords.
Maintenance is the process of ensuring that buildings retain a good appearance and operate at optimum efficiency.
Andrew Wyllie CBE, the CEO of Costain, becomes the 154th ICE President.