Don’t forget the consequences
Many of the consequential improvement requirements of Part L of the 2006 Building Regulations are reinforced in the 2010 version. So building services engineers need to ensure they don’t forget what these requirements are, suggests Ant Wilson.
With the arrival of the Building Regulations 2010, building-services engineers again have to get to grips with new requirements. On the refurbishment side it is just as important not to forget what was in the 2006 version.
Experience has shown that many people involved in refurbishment projects have not followed the 2006 requirements for consequential improvements, either because they were not aware of them or it slipped their minds. This is reflected in Part L 2010, which has not changed the requirements very much but does emphasise these requirements more strongly. There are some changes though, and these are discussed in more detail later in this article.
However, the changes are meaningless if people do not take the trouble to make themselves aware of them. And, yes, when you are busy the prospect of wading through lengthy technical documents is unappetising, but it has to be done.
At this point it is worth reminding readers that Part L implements the Energy Performance of Buildings Directive, so compliance is a legal requirement. In many cases such compliance will be self-certified so it is important to get it right. Unfortunately, the success of schemes such as GasCert and Part P certification in the residential sector does not seem to have reached the commercial/industrial sector yet.
For example, we sometimes seem to get so fixated on plant efficiency that we forget about basic requirements such as insulation of pipes, ducts and vessels. It is surprising how many new buildings have unlagged pipes — and it is extraordinary that these buildings are certified.
Getting to grips with Part L means that you become more aware of the factors that trigger consequential improvements. As a quick reminder, in relation to non-dwellings, these are laid out in Part L2B and refer to work carried out on an existing building with a useful floor area of over 1000 m2. In such circumstances, any of the work listed below triggers consequential improvements.
• Extensions
• Material change of use
• Material alteration
• Controlled items — the provision, extension, alteration or renovation of a controlled element, service or fitting; i.e. walls, floors, roofs and alteration and renovation work as well as replacement.
Recognising the triggers is only part of the story though. It is also important to understand the extent of consequential improvements that is required. For example, if an existing building has a large extension, the consequential improvements should represent 10% of the value of the new work. So if you build a £30 million extension, spending £50 000 on upgrading lighting in the old building is nowhere near enough. Yet this fictitious example does typify how consequential improvements are often misunderstood.
Another common misunderstanding is that heritage buildings are exempt from consequential improvements. There may be limitations in terms of affecting the appearance of a building, but there is no excuse for not upgrading plant and systems that are hidden from view.
As mentioned earlier, there are also some new elements in Part L 2010, and to some extent this imposes a requirement to refer not just to Part L but also to related documents — following a ‘daisy chain’ of information. For example, plant replacement should be done in accordance with the relevant compliance guides to ensure that the appropriate standards, seasonal energy efficiency ratios and emissions levels are achieved.
Emissions are important because they will vary with fuel type. For example, it is possible to replace an oil boiler with a less efficient gas boiler because the emissions from gas are lower. Similarly, replacing an electric chiller with an energy efficiency ratio (EER) of 2.4 with an absorption chiller with an EER of just 0.9 will be acceptable where the absorption chiller is using waste heat, as overall emissions are reduced. To that end Part L 2010 now cross-references to the greatly extended list of fuel CO2 emissions factors in SAP 2009 (March 2010).
Additionally, when identifying the most appropriate consequential improvements to be made, notice should be taken of the Recommendation Report produced for the Energy Performance Certificate. This will highlight things that could be done better (in terms of energy performance), thus providing a ‘shopping list’ of desirable improvements that you could introduce, starting with low-cost measures that have a high carbon impact.
It is also worth noting that in some areas it will be advisable to refer to the Domestic Building Services Compliance Guide, for information on solar heating systems.
Part L 2010 also re-emphasises the importance of building log books in helping to ensure that the services are efficiently controlled, you know how much energy they are using and that the improved energy performance of any consequential improvements are maintained through the life of the building.
The importance of compliance is reinforced by CIBSE’s ‘Non-compliance costs’ campaign, which urges building-services engineers to play a key role in ensuring compliance. When it comes to refurbishment, this will be achieved not just by taking note of the changes to the new requirements of Part L 2010 but also revisiting the 2006 version to make sure we fully understand them.
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Ant Wilson is director of building engineering with AECOM.
