Recent revisions to Part L mark the next step towards zero carbon homes but do they go far enough asks Bjorn Sejr Nielsen, Marketing Director at Danfoss. In his overview of the changes he highlights the role of heating control in achieving the new regulations.
Energy efficiency standards required under Part L Building Regulations play an important role in helping the UK meet its legally binding obligation to reduce greenhouse gas emissions. Regular revisions to Part L have raised these standards and the latest update, which came into force on 6th April 2014, demands a 6% improvement on 2010 regulations for new homes and 9% for non-domestic buildings. Whilst any uplift will contribute to cutting carbon emissions from UK buildings, these figures are lower than those originally proposed by the government.
Challenging economic climate
The key question, therefore, is should the changes have been tougher given the fact that the zero carbon target for new homes is just two years away? The current financial climate was clearly a factor in the decision to take a less ambitious approach rather than introducing stricter measures that might actually deter people from upgrading their homes’ energy performance. This decision was supported by negative feedback from homeowners and installers to the prospect of legislation on ‘consequential improvements’ to existing properties. According to a survey conducted by the Energy Savings Trust 38% of households would be put off doing any energy saving enhancements if standards were made too stringent. Similarly, installer groups felt that making standards too complicated and costly for their customers to comply with, even with Green Deal incentives, would make it even harder to win work in what are already challenging economic times. Concerns were also raised on how to police harsher rules and appropriate penalties for non-compliance.
New central heating systems
So let’s look at the main changes to Part L in relation to zoning and control of new central heating systems. When installing a new system in properties with a floor area of under 150m2 there must now be a minimum of one space heating zone with independent time control. This control can either be a room thermostat (or programmable room stat) and TRVs on all radiators, except radiators in the reference room(s), or individual networked radiator controls in each room. New systems in properties with a floor area of more than 150m2 must have a minimum of two space heating zones with independent time control options as per smaller properties. The same requirements also apply to new heating systems where existing pipework is utilised.
Community heating systems
The new Part L also covers requirements for dwellings with community heating systems. Properties up to 150m2 must have a minimum of two zones with independent temperature control, one of which must be assigned to the living area. A minimum of two zones with independent time and temperature control must be installed where the floor space is larger than 150m2. Temperature control must be provided either by room stat or programmable room stat in each zone, or in the main zone with TRVs on all radiators in other zones, or a combination of both. No boiler interlock is required to the HIU, for example, but from 1st June 2014 new metering requirements will be introduced.
Mandatory TRVs
Whilst these changes represent a reduction in zoning in houses up to 150m2, installing TRVs on all radiators is still mandatory, including radiators in bathrooms now. It has long been known by members of the BEAMA Heating Controls Group TACMA, of which Danfoss is a member, that fitting basic, standard controls to UK heating systems will not only improve comfort but will greatly enhance the efficiency of the system. This view has recently been confirmed by a research project conducted by Salford University into home energy consumption. Independent tests carried out in the University’s Energy House showed that energy consumption in a typical UK house can be reduced by up to 40% by installing a room thermostat and a full set of TRVs (thermostatic radiator valves), which is far more than previously assumed, and payback is typically 9 to 18 months.
Compliance date
Although the new Part L Building Regulation took effect from 6th April this year, ongoing installations which started before this date do not have to comply with the new rules. Also, changes in Part L 2014 do not apply if a building notice, including a full planning application, was deposited before 6th April and where building work commences before 6th April 2015.
To sum up, many believe that Part L will need to get much tougher than this latest revision if the industry is to achieve the ultimate goal of zero carbon homes by 2016. So watch this space!
For more information about Danfoss Heating Efficiency Packs, including where to buy, please visit www.heating.danfoss.co.uk