Part L 2013 has finally arrived

Thomas Vazakas | RPS Health, Safety and Environment  

The much anticipated Part L 2013 which was due to come into force in October 2013, following consultation that began in January 2013, was finally officially launched at the beginning of October  During the launch it was promised that the Approved Documents and beta versions of the SAP and SBEM software would be issued within weeks. However it took until the 25th November before Approved Documents L1A and L2A were released and there is still no confirmed release date for the Approved Documents for existing buildings. Meanwhile the test version of SBEM software is due to be released on 2 December and the SAP software on 9 December, at which point practitioners will no doubt begin to discover anomalies within the software. Nevertheless, there is one certainty – that on the 6th of April 2014 all buildings will have to comply with Part L 2013!

As Part L regulations set out the energy efficiency requirements for buildings, Part L 2013 was always seen as critical to making all new homes zero-carbon by 2016 and all non-residential building zero carbon by 2019 – a key part of the Government’s commitment to cut the UK’s carbon emissions, as stated in the 2013 Budget.  Now Part L 2013 is seen as an important ‘technical’ step to strike a balance between Zero Carbon and growth commitments, with options for Allowable Solutions and the Housing Standards Review leaning heavily towards growth at all costs.

Domestic Buildings

Most of the changes in Part L 2013 focus on residential new build, which makes sense considering that the zero carbon target is only 2 years away. There is a 6% uplift in the Target Emissions Rating (TER) on 2010 levels. This is slightly lower than the 8% target originally put forward as the Government’s preferred option when it consulted in 2012, the reasoning being that “it was difficult for detached houses to achieve the 8% target through fabric measures only, on basis of cost effectiveness and consistency of construction.”

Arguably the most significant difference between 2010 and 2013 Building Regulations is the introduction of Target Fabric Energy Efficiency (TFEE) and Dwelling Fabric Energy Efficiency (DFEE). These two new mouthful acronyms are measured in kWh/m2/yr and practitioners will need to learn to use them a lot in the short term future. For a dwelling to comply with Criterion 1, the DER must be less than the TER and the TFEE less than the DFEE. So, what is the TFEE and how is this calculated? The TFEE is approximate equal to the Interim FEES (Fabric Energy Efficiency Scheme) level, as defined by Zero Carbon Hub a couple of years ago. For those of you familiar with the Code for Sustainable Homes, FEES is the Ene2 credit.

Another new element within Part L 2013, is the introduction of the Elemental Recipe. This recipe includes a performance specification for the building fabric and services, which is compliant with Criterion 2 and if it is followed by the design team should achieve compliance in almost all dwellings for Criterion 1. [1] This recipe will give a compliant DER and a compliant DFEE (as the TFEE is calculated by increasing the kWh/m2/yr of the elemental recipe by 15%). This doesn’t mean that all buildings need to be designed in line with the recipe. Developers and the design team can always decide to follow a different specification if their approach still meets the TER and TFEE.

For existing buildings no changes have been made.

Non-Domestic buildings

In Part L 2013 there is a target of 9% aggregate reduction in CO2 emissions compared to 2010 levels. This is again lower than that proposed in the consultation documents (11%).

Contrary to changes to Part L for domestic buildings, Part L2A 2013 has no introduction of a DFEE/TFEE requirement nor an elemental recipe. The main difference between Part L 2013 and 2010 for commercial buildings is the split of the side lit notional building (e.g. office), to side lit heating only and side lit with air conditioning.   There are no changes to the notional top lit (e.g. warehouse) or no lit (e.g. plant room) buildings.  Within Criterion 2 the U-values for the notional building remains the same, with some small changes in the services. The most significant change within Criterion 2 is the introduction of LENI (Lighting Energy Numeric Indicator) methodology to ensure compliance for lighting, which is something that the lighting industry has been arguing for a long time.

On existing buildings there are minor changes to the fabric standards for replacement or renovation, and a number of changes on the replacement of services, in line with the changes to the Non-Domestic Building Services Compliance Guide.

Transitional provisions

The transitional provisions for Part L 2013 are the same as for Part L 2010. Effectively, if a Building Regulations submission is made prior to 6th April 2014, the current regulations apply, providing work on that application commences within twelve months.  A valid commencement is any building work, such as excavation of foundations or laying of drains. The transitional provisions will apply to the whole Building Regulation application which means that only one plot on a site will need to commence to validate all of the plots on the application under the current Part L requirements.

Will we meet zero carbon?

Based on the watered down changes and the long transition lead-in times, some people (including the writer) might argue that the changes in Part L 2013 are minimal. Which raises two big questions. First of all why it was delayed for so long, if no significant changes were to be made and secondly, and possibly most importantly, how is the industry going to achieve the zero carbon target of 2016? Because, within two years the building industry needs to find the silver bullet to reduce its CO2 emissions from new housing down to zero. How are they going to do this? The answer – through allowable solutions – is possibly the worst fear of most professionals. Developers will end up paying a fee to offset their emissions. The consultation for allowable solutions is still out so there is nothing concrete as to where this money will be spent. It could be to fund off-site renewables. But it could as easily be spent on refurbishing an existing block within the same local authority area.

Will this mean that we meet Zero Carbon in 2016? As far as the Government is concerned, yes, they will have technically met their target. However we all know that this will not be Zero Carbon.


[1] Criterion 1: achieving TER. Criterion 2: limits of design flexibility

Twitter icon
Google icon
LinkedIn icon
Pinterest icon
Reddit icon
e-mail icon