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Part L 2010 – getting there slowly

by Mel Starrs on May 26, 2010

in Part L

So Part L AD’s did finally get released. I figure most of the readers of my blog will have noticed this. I wanted to write a full review but unfortunately we are still twiddling our thumbs waiting for supporting documentation (this sound familiar at all, or am I getting (more) cynical and grumpy in my old age?).

For those who have had trouble finding the page with the new approved documents, it can be found here. The only supporting document released so far “Non-Domestic Building Services Compliance Guide 2010 Edition” is available here. The crucial missing piece of the jigsaw is the 2010 NCM Modelling Guide, which will detail exactly how the aggregated 25% split across non-domestic buildings will work. I’m guessing the reason why cSBEM v1.4 is also not released is because the two need to be issued at the same time. I expect when the modelling guide is issued it will live on the same website as the NCM and SBEM, here.

The key change is under paragraph 4.6 in the Approved Document:

Note that the TER is no longer based on a 2002 notional building and an improvement factor; for 2010 it is based on a building of the same size and shape as the actual building, constructed to a concurrent specification. This concurrent specification for Part L 2010 is given in the 2010 NCM modelling guide. Developers are still given the freedom to vary the specification, provided the same overall level of CO2 emissions is achieved or bettered. This approach to target setting has been adopted because the level of improvement that can reasonably be expected varies significantly by building sector, and so a blanket improvement factor would be inequitable. The specification delivers an overall 25% reduction in CO2 emissions across the new-build mix for non-dwellings sector (the so-called ‘aggregate approach’). Some building types will be required to improve by more than 25%, some by less, but all should achieve the required level of improvement at approximately the same cost of carbon mitigation.

Until the NCM Modelling Guide is released, we have to second guess the aggregate approach (using the figures from the initial consultation) and hoping cSBEM is not a million miles too wrong. *Sigh*.

This throws up interesting questions for what is going to happen to EPC ratings and BREEAM ENE1 credit. Currently credits are awarded on an EPC score. The EPC score is a CO2 index (and reflects the carbon per m2). A compliant building under Part L 2010 will still have a CO2 index, presumably. But a hotel will be compliant with a CO2 index which is considerably different to a shallow plan office, for example. Will the rating bands for EPC’s need to be adjusted for different building types? And similarly for BREEAM credit ENE1?

Also where will the points be awarded for BREEAM 2010 Excellent – an EPC of 40 in 2010 will be easier to gain (as in it is closer to the pass rate) – will the goalposts move, ie an EPC of 30 or less?

I am going to a BREEAM consultation event very soon, so hope to have some answers then.

For reference, my original posts on the consultation are available: part 1, part 2 and part 3.

One of the best posts I have seen so far is this over at the IES blog – well worth checking out the pdf which shows really clearly the difference between the old notional building and the new version.

  • http://jtecservices.co.uk LinniR

    Mel, a question, one that you may have an answer for at your fingertips.
    You said that the SBEM EPC score is a CO2 index (and reflects the carbon per m2). But, it’s the BER that is a CO2 index – the actual EPC score is a ratio between the CO2 index for the building being assessed c.f. the target. You then said that a hotel, for instance, will be compliant with a CO2 index which is considerably different to a shallow plan office – again I guess you are talking about the BER there, i.e. the BER has met the target TER. So when the EPC score (the ratio) is calculated for the different building types, will that compensate for the different building types, meaning that no adjustment to the EPC bands for building type will be needed?
    I don’t do so much with SBEM any more (thank goodness) so won’t be going to that BREEAM consultation event, but am looking forward to your further updates on this.

  • http://jtecservices.co.uk LinniR

    Mel, a question, one that you may have an answer for at your fingertips.
    You said that the SBEM EPC score is a CO2 index (and reflects the carbon per m2). But, it’s the BER that is a CO2 index – the actual EPC score is a ratio between the CO2 index for the building being assessed c.f. the target. You then said that a hotel, for instance, will be compliant with a CO2 index which is considerably different to a shallow plan office – again I guess you are talking about the BER there, i.e. the BER has met the target TER. So when the EPC score (the ratio) is calculated for the different building types, will that compensate for the different building types, meaning that no adjustment to the EPC bands for building type will be needed?
    I don’t do so much with SBEM any more (thank goodness) so won’t be going to that BREEAM consultation event, but am looking forward to your further updates on this.

  • admin

    Linn – you might have hit the nail on the head there! That would mean the bands could stay the same – but this add even more confusion? We’ll have to wait and see!

  • admin

    Linn – you might have hit the nail on the head there! That would mean the bands could stay the same – but this add even more confusion? We’ll have to wait and see!

  • http://jtecservices.co.uk LinniR

    Everything about SBEM is confusing, so why worry about one more thing? Seriously though, it’s not uncommon to forget the impact of this simple difference between SBEM and SAP. SAP is an absolute indication of performance – based on energy cost per m2, but pretty closely mapped to CO2 emissions most of the time – but the SBEM EPC rating is a relative indicator of performance compared to a standard. I’ve never received any explanation of why the difference; surely the EPC should indicate the absolute performance for non dwellings, just as it does for dwellings? What does BREEAM use – it is the EPC result or the DER?

  • http://jtecservices.co.uk LinniR

    Everything about SBEM is confusing, so why worry about one more thing? Seriously though, it’s not uncommon to forget the impact of this simple difference between SBEM and SAP. SAP is an absolute indication of performance – based on energy cost per m2, but pretty closely mapped to CO2 emissions most of the time – but the SBEM EPC rating is a relative indicator of performance compared to a standard. I’ve never received any explanation of why the difference; surely the EPC should indicate the absolute performance for non dwellings, just as it does for dwellings? What does BREEAM use – it is the EPC result or the DER?

  • admin

    @LinniR
    BREEAM ENE1 uses EPC score. An engineer can calculate the CO2/m²/yr of a design fairly early on, but needs a lot more detail to get to an EPC rating (as you need the DER). This causes problems in predicting what BREEAM score is likely at an early stage, and even more problems if planning ask for BREEAM certification at planning stage. I’ll feed all this back to the BRE at the consultation, but it’s too late for Part L now…

  • admin

    @LinniR
    BREEAM ENE1 uses EPC score. An engineer can calculate the CO2/m²/yr of a design fairly early on, but needs a lot more detail to get to an EPC rating (as you need the DER). This causes problems in predicting what BREEAM score is likely at an early stage, and even more problems if planning ask for BREEAM certification at planning stage. I’ll feed all this back to the BRE at the consultation, but it’s too late for Part L now…

  • MartinL

    The NCM Modelling Guide has now been published at http://www.2010ncm.bre.co.uk – an initial skim shows some departures from what the consultation document suggested, but it will take a bit more digging to establish whether what it says means a post-2010 EPC will be comparable with a pre-2010 EPC.

  • MartinL

    The NCM Modelling Guide has now been published at http://www.2010ncm.bre.co.uk – an initial skim shows some departures from what the consultation document suggested, but it will take a bit more digging to establish whether what it says means a post-2010 EPC will be comparable with a pre-2010 EPC.

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  • Nkwc

    Hello,

     

    I found thi blog because I am about to take a NDEA course.  I am confused
    about the software.  The course I am looking at uses IsBEM software, but at
    Stroma they use SAP software.  Does anyone know what the difference is and is it better to learn
    one over the other and select a training course based on the software used?  Or
    am I confused.  Is SAP for domestic and IsBEM for non domestic.  Also there was
    some talk of reference to Co2.  Also , do you know if the methodology used for
    DEA and NDEA used comply with ISO 14064 (1).  Many thanks