GLA Energy and Cooling Hierarchy: 2022 Changes

GLA Energy and Cooling Hierarchy: 2022 Changes

This month brings in the biggest changes to energy targets in English Building Regulations since SAP was first introduced over 15 years ago.

New homes will need thicker insulation, low carbon heating and solar panels to meet the 31% uplift on the previous emission targets.

Many planning authorities already set higher requirements than the standard Building Regulations, so what’s going to happen to local policies now the national targets have been significantly improved?

The GLA, which manages planning policy in London, sets some of the strictest carbon targets for new building projects anywhere in the country.

Their Energy Hierarchy has been adjusted to align with the targets set out in the new Approved Documents Part L (energy efficiency), and Part O (overheating).

These changes will apply to all new submissions to the GLA moving forward.

Energy targets

Under previous London Plan rules, developers needed to show a 10% reduction over the Target Emission Rate through fabric improvements alone (15% for non-residential), and an overall saving of at least 35% when low carbon technologies and renewables are added into the mix.

On top of this, any remaining CO2 from the buildings must be offset by paying into a carbon offsetting fund.

The targets in the new Approved Document Part L (2021) encourage the use of heat pumps, discourage the CO2 compliance target by 31%.

The GLA has not only confirmed their 35% additional reduction requirement is remaining in place on top of the new Building Regulation targets, but they also expect residential areas to push further and aim for a 50% reduction.

But this isn’t as scary as it sounds, as long as the development adopts a heat pump strategy. Both the GLA and new Building Regulations are pushing the use of heat pumps, and designers can expect to see a healthy reduction over the targets if they use this type of heating system instead of gas boilers or CHP engines.

Overheating

The GLA require TM59 modelling on all major schemes. This 3D forecasting method provides a detailed review of the overheating risk of a development.

Passive design measures and shading strategies are encouraged, while the addition of energy intensive air conditioning systems will only be approved as a last resort.

Until now, Building Regulations haven’t covered overheating in any detail, but the new AD O introduces mandatory checks for all dwellings.

Most new homes in England will be able to comply using a Simplified Method, but it’s recommended that every development in London is assessed against the Dynamic Thermal approach, which uses TM59 modelling.

However, the parameters in the background of AD O are more strict than the conventional TM59 approach used by the GLA, which makes it more difficult to reach compliance.

Parameters are a pre-set list of assumptions built into the model. One parameter, for example, assumes the occupant will open all windows when the internal temperature hits 26 degrees.

To avoid confusion between the two targets, the GLA has updated its policy to require the AD O Dynamic Thermal is followed as standard.

This is a sensible step, as setting different targets between planning and Building Control stages could leave developers yo-yoing between the two stages to find a compliance sweet-spot.

Energist’s Technical Team includes specialists in GLA Energy Strategies, Dynamic Thermal modelling for both TM59 and AD O targets. Contact us to make sure your upcoming projects fall in line with both the latest GLA policy and Building Regulations targets.

If you have any questions about these Building Regulation changes, feel free to contact the Energist team. Otherwise keep an eye out on our ‘Articles’ page for more guidance about the incoming changes.