Part L2a England 2021 consultation

[Terence]

The consultation period for the next update to the regulations for non-domestic buildings in England was opened on 19th January and will close on 13th April 2021.

The official consultation document can be viewed here: https://assets.publishing.service.gov.u ... cument.pdf

The contact details for responding prior to 13th April can be found in the document.

You can register & download the consultation version of iSBEM here: https://www.uk-ncm.org.uk/page.jsp?id=30

England Consultation NCM Modelling Guide 2021 edition: 2021 NCM Modelling Guide can be viewed here: https://www.uk-ncm.org.uk/filelibrary/N ... _Draft.pdf

One major change is to the CO2 emissions factor for Grid Supplied Electricity which has reduced greatly from the 2013 value and will vary depending on the month of the year. You can see the proposed factors in the following document here: https://www.uk-ncm.org.uk/filelibrary/B ... n_SBEM.pdf

As it is a consultation period nothing is finalised but IES will as ever strive to have our own software approved in time for the "go live" date, whenever that will be. We don't currently plan a beta but if the software is available end of this year we will consider putting one out.

[Terence]

Comparison between the 2013 Notional Building and the proposed 2021 Notional Building inputs.



Other notes on the proposed changes

The new regulations are intended to deliver on average a 27% reduction in Carbon Emissions compared to the existing Notional Building. As with previous updates some building types will be more than 27% and some will be under 27%.

A new NCM Activity Database will be included for Part L2a 2021.

The Criterion 1 Pass/Fail for Compliance is dependant on both the Actual Building Emission Rate (BER) being lower than the Notional Building Emission Rate (TER) & the Actual Building Primary Energy Rate (BPER) being lower than Notional Building Target Primary Energy Rate (TPER).

The Notional Building will benefit from the inclusion of PV.

2016 CIBSE Weather Files will now be used for Compliance & EPC calculations.

Some new NCM System Types

Changes to Demand Control ventilation factors for Auxiliary Energy calculations

Thermal Bridging factor increased for constructions in both buildings to 25%

Criterion 3 benchmark glazing types have reduced g-value's.

Notional Building HWS will have a defined Storage & Secondary Circulation setup.

[LeightonSS55]

Thanks for confirming the above information, very helpful.

I note that the 2021 consultation verson of SBEM has been released - just wondering if you are planning on having a VE Compliance DSM equivalent? i.e. VE Compliance 2021 in the interim to test the impact of the changes within IES-VE, rather than wait for the official release.

I'd like to test out how this will impact EPC ratings & Part L performance on existing models and don't really want to build an SBEM from scratch.

Thanks

[PCully]

Hi,

we won't release a consultation version as we can't move on with the development until the NCM is finalised (too much framework depending on the rules). if possible I'd like to see a public beta of our dsm prior to go live but again will depend on the time between final NCM and the official gi live dates if our development can produce that in good time

Phil

[Terence]

The BRE have released their version of iSBEM approved for the Part L 2021 regulations and the approval pack to third party developers seeking approval for the new regulations, you can read about the update on their latest news page here

We are already working on development of this with the aim of having it approved for both DSM and SBEM methods before the go live date on 15th June 2022.

The team are working with the intention to have the software fully validated ahead of the deadline, if we can share a preview version before then as a beta we will. To register an interest in this please email beta@iesve.com, we can't give an eta but will be in touch with more details when we can.