How the Latest Building Regulations will affect your EPC's

Posted by NRG Focus on 5th March 2022 -

The Government has finally issued the new building regulations Part L aimed at making Domestic and Non-Domestic buildings greener and more efficient. Heating and powering buildings currently account for 40% of the UK’s total energy usage. In 2019 the government introduced a legally binding target to reduce greenhouse gas emissions to net zero by 2050

Energy Performance Certificates are calculated using the National Calculation Methodologies (SAP and SBEM) and for each fuel type, there is an associated amount of carbon per kWh.

 

1.     Mains Gas 0.206KgCO₂eq/kWh

2.     Grid Electricity 0.591KgCO₂eq/kWh

 

As can be seen electricity has always been the poor relative with a carbon factor approximately 2.5 times worse than mains gas, this resulting in a poor EPC rating for electricity heated buildings.

The main reason behind this has always been the way in which electricity is produced in the UK, fossil fuelled power stations and the inefficiency in terms of losses through the grid. For every 1 kW electricity consumed in your home the power station has to produce 3 kW.

Over the last decade the UK has installed significantly more renewables especially in offshore wind and this has ‘greened up’ our grid electricity supply this being the reason why the Government is pushing electrical heating systems, especially heat pumps and the fuel for our cars in the future.

The new Building Regulations, PartL will have new updated carbon emission factors for grid supplied electricity, these will be approximately 20-25% less than mains gas per kWh.

How will this effect my building?

In England and Wales, when an EPC is calculated using the approved software ISBEM the “actual building” is compared against a “reference building” The the software compares the kWh/m² for the following:

1.     Heating

2.     Cooling

3.     Auxiliary

4.     Lighting

5.     Hot water

The reference building is always heated by gas and naturally ventilated so, in the past an electrically heated building, fuelled by ‘high carbon mains electricity’ was compared against a much cleaner fuel for the reference building.

After the change this year (June), that same building will now have a much lower carbon factor assigned to it, ‘clean’ electricity” compared against the same gas heated building resulting in the rating improving, even if just heated via electric panel heaters.

Essentially your building will very likely get a better rating without doing or spending anything.

What Level is my Building and what software should I use?

There has always been confusion as to what level of complexity buildings are regarding Commercial EPC’s, is it Level 3, 4 or 5?

In very basic terms:

Level 3 – Naturally ventilated buildings with basic Heating, Ventilation and Air Conditioning (HVAC) – Using standard ISEM software

Level 4 – Mechanically Ventilated with a Centralised HVAC system. - Using standard ISEM software

Level 5 – As level 4 but also with a Central Glazed Atrium, atria (internal glazing has to be modelled), significant external shading and daylight controls. – Dynamic Simulation Software (DSM)

 

DSM software allows natural light to flow from the glazed atrium into the offices surrounding the atrium, this reducing the lighting load, this also works very well on industrial units with a large number of roof/skylights.

Level 5 software can be used on any building complex. A DSM Level 5 rating is not always better, in some cases it is worse, but it is more accurate. A client could spend money on improvements based upon simplified findings where some more accurate modelling might have been sufficient to show the buildings true rating.

With the new MEES legislation and having to eventually achieve a B rating, accuracy is extremely important.