IES Blog

The news about this is out in the industry but spreading slowly!!  Please pass it on…

It was confirmed by the Government the other week that although Part L 2010 will come into force on 1st October 2010 as planned; the related EPC section has been delayed until 27th March 2011.

Obviously this has implications for all Energy Assessors – both domestic and non-domestic. 

As mentioned, this deferment will not affect implementation of Part L 2010 for Building Regulation purposes on 1st October 2010, or the transitional provisions already laid before parliament.  The main complication comes when an application is submitted after 1st October 2010 and the project completed before 27th March 2011, therefore requiring an EPC. 

Calculations for building regulations DER/TER (both at design and completion stage), will be to Part L 2010, but the EPC will have to be done to Part L 2006 methodologies.  In many case this will mean extra work for the EA with no additional return.  For example, if using iSBEM separate models will need to be built in different versions of the software; one for Building Regulations compliance and the other to calculate the EPC!

Though it is not expected that this will affect many developments, as most will not be in a position to lodge an EPC within the delayed period, what has been overlooked is the need for design professional to understand the relative difference between EPC ratings – which will be one of the main questions asked by their clients!

Lack of clarity on exactly what the changes to EPCs calculations will be will hamper understanding, and ultimately reduce clients and designers opportunity future-proof buildings.

Designers who need to go back to a previous software version for final Part L ‘as built’ compliance will also face many of the same issues and its therefore essential that any software user who wants the flexibility to switch between 2006 and 2010 versions for whatever reason makes sure that their software will enable this without doubling their effort.

As a consequence, we’re in the process of adding a new feature to our software allowing designers to easily switch between our VE Compliance 2010 and 2006 modules.  This previously unavailable backwards compatibility (of the VE Compliance model) will enable IES users to avoid double input of data resulting from the delay in the new EPCs.  While this will provide a useful facility for projects during the transition between the 2006 and 2010 regulation frameworks, it will also aid in allowing users to easily go back to Part L (2006) if required for old projects.

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Tags:Energy Assessors, EPCs, IES, Part L, Part L 2010, ve-compliance

Responses to consultations on the proposed changes in Part L 2010 have been talking up quite a bit of my time recently.  Obviously, an area of particular interest to us is the calculations tools. 

The Building Research Establishment (BRE) developed SAP and SBEM drafts to support the Part L 2010 consultation package, both of which we’ve been looking at in-depth.  However, in this blog I’m just going to look at the proposed changes to SAP.

For SAP 2009, the proposals centre around the adoption of a monthly calculation method instead of the current annual calculation, with the addition of factors to address thermal mass and cooling.  This has a number of ramifications for various parts of the calculation.  The justification for this is the need to consider the energy balance at different times through the year with more rigour, for instance within very-low energy dwellings.

While there is certainly a need to ensure compliance methodologies don’t penalise the design techniques required to achieve very low-energy dwellings, could it be that that changing the current SAP methodology is an unnecessary route – one that is both expensive and potentially a disruptive burden on the industry?

The current SAP approach, based on a worksheet, is well understood by its users and is a simple, but reasonably transparent assessment suitable for the majority of conventional dwellings.  When you consider that there are other monthly calculation tools already developed and in-use in the non-domestic arena, why would the government invest taxpayers money in the research, development and implementation of another methodology especially when public spending is under severe constraints?

SBEM and DSM could cheaply and easily be extended to the domestic sector at virtually no cost, as could the existing training and accreditation routes.  In fact, many designers of low energy dwellings have already tried and tested dynamic thermal simulation in their day-to-day design.  SBEM is a monthly calculation (as is being proposed for SAP 2009), whereas DSM is a 8760 hourly annual calculation.  SBEM and DSM also provide a way to include treatment of thermal mass and cooling.

By offering a choice of calculation engine at the domestic level; SAP (simple heating only dwellings), SBEM (most dwellings) or DSM (all dwellings), all low energy technologies could be studied in the right level of detail by those with the right level of skills and without needless upheaval and cost.

The current SAP calculation could be left essentially as it is – negating the need to develop yet another publically funded energy calculation tool, with the associated significant upheaval and burden on the industry of re-training and accreditation.

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Tags:Building Research Establishment, Part L 2010, SAP 2009, SAP Calculation