Part L2A 2013 – “How to pass” – Part 1

Part L2A 2013

The Building Regulations Approved Document Part L2A 2013 for non-domestic buildings have recently been released. These regulations come into force in England on 6th April 2014. Separate rules apply to Wales, Scotland and Northern Ireland.

Transitional arrangements will apply and these are the same as for the 2010 regulations update – if the site is registered with Building Control before April 6th 2014 and work is started on site (excluding demolition) within a year of this date the 2010 regulations can still be applied.

How compliance is assessed

In order to assess compliance with the regulations, the building geometry, fabric and systems details are entered in to an approved software package. The CO2 performance of this building is modelled and compared to the CO2 performance of a baseline ‘Notional’ building under certain standard conditions such as occupancy and hours of use. In order to pass, the predicted building CO2 emissions (the Building Emissions Rate or BER) must not be greater than those of the Notional building. The Notional emissions in kgCO2/m2 per year are known as the Target Emissions Rate (TER).

In addition to complying with the CO2 emissions target (Criterion 1), minimum standards must also be met -for example for U-values (Criterion 2) and the building must comply with the limit on solar gains (Criterion 3). There are 2 further criteria relating to the quality of construction and commissioning and on providing sufficient information for energy-efficient operation (Criteria 4 and 5).

Reduced carbon targets

On average (for non-domestic buildings) the CO2 target for the 2013 regulations are 9% lower (tougher) than for the 2010 regulations. This average is based on the UK mix of building stock and therefore will vary by building type – an office would need to be around 12% better than 2010 Part L and a school around 8% in terms of CO2 emissions.

Next: Part L2A 2013 – “How to pass” – Part 2