All change for the Building Regulations
Author : Hywel Davies, CIBSE technical director
The last few months have seen some significant changes to the Building Regulations. The latest revisions to Part L were published earlier this year. Whilst the latest changes are not on the scale of the 2006 revision, there is plenty of detail under the surface. There are changes to Part L, which covers “Conservation of Fuel and Power”, or Energy Efficiency, in plain English.
There are four new Approved Documents, ADL1A&B covering new homes and work to existing homes, and ADL2A&B covering other new buildings and existing buildings, respectively.
There are also two new compliance guides, covering both domestic and non domestic building services. Much of the detailed guidance relating to specific “fixed building services” systems has been moved to the compliance guides rather than the Approved Documents. This means that the detailed guidance on lighting, hot water, heating and cooling and ventilation systems is now in the compliance guide, which is a separate document.
It is important to be aware that Part L, the regulatory requirement, is just a few short paragraphs. It requires that “Reasonable provision shall be made for the conservation of fuel and power...” and that “Fixed Building Services [shall be] energy efficient [and] have effective controls”. But Part L is a part of the Building Regulations, and is legally binding. In contrast, the Approved Documents are officially sanctioned guidance documents, along with the compliance guides.
The ADs and compliance guides provide guidance on how to comply with the requirements in Part L, in other words, they explain what “reasonable provision” could look like. But they are not prescriptive, except where they quote the regulations, and each document makes it clear that there is freedom to make “reasonable provision” in other ways, as long as the Building Control Officer accepts the alternative solution.
These various changes might not, at first sight, seem to affect the electrical sector. But with changes to the carbon emissions targets, which are now 25% more stringent than 2006, together with new carbon emissions factors for electrical energy, which increase the carbon emissions allocated to each kWh of electricity used by a third, the calculations of energy efficiency will be a little more demanding for electrical products. There is also a growing interest in heat pumps, low energy lighting products and feed in tariffs, which will be very relevant when considering Part L compliance and the selection of electrical products in buildings.
The method of calculating the target CO2 emissions factors for a new building has changed. In the 2010 edition the notional building used as the comparator for assessing the target emissions rating is different to the 2006 version. The notional building is now similar in form and geometry to the proposed building, but the allocation of rooflighting has changed, too. This in turn affects the role of daylight and, of course, in the absence of daylight on electric lighting. Combined with the increase in emissions factor for electrical energy, which has changed to 0.592kg/kWh from 0.422kg/kWh, there is likely to be considerable pressure to reduce the energy consumed in electrical systems. This is likely to increase the focus on energy performance, on energy labels and on better controls to reduce energy use in electrical systems.
Lighting is perhaps the biggest single area of direct interest to electrical suppliers and installers. It uses a significant proportion of energy in offices, schools, shops or factories. According to the International Energy Agency, 19% of electricity worldwide is used for lighting. So Part L might be expected to encourage the use of the British and European Standard developed to enable energy efficient lighting to be specified. BS EN15193, the standard for the design of energy efficient lighting for buildings, describes the Lighting Energy Numeric Indicator – LENI – which demonstrates the efficiency, or otherwise, of a lighting system. It specifies the annual lighting energy per m2 and is a measure of consumed energy, embracing all aspects of the building, and was prepared by the lighting industry and lighting professionals for this purpose.
In contrast Part L does not use LENI, but sets limits on equipment efficiency through installed power density. Unfortunately this can result in installations that comply with Part L but do not provide effective lighting. Inevitably, the lighting will be supplemented by additional light sources, increasing the energy consumption within the space, which is not really the intended outcome. Faced with the Part L requirement and guidance in the Approved Document and Compliance Guide, what should a lighting designer do?
Many lighting professionals consider the daylight element of the current guidance is extremely weak. It takes no account of location, orientation, shading or dirt. The guidance on lighting controls is also inadequate. Automatic controls are essential and should not be an option, which in the AD and compliance guide they currently are. Automatic lighting controls should not be seen as an option, but as a requirement under Part L 2010. Enough studies have shown that humans do not switch off lights, either on leaving a room or when there is enough daylight without them.
So lighting designers can point to the requirement for lighting systems to be energy efficient and have effective controls, turn up BS EN15193 and use it, and explain to the client, the building control officer and anyone else who asks that this is the European Standard method for designing energy efficient lighting. It should therefore be taken as making “reasonable provision for the conservation of fuel and power” in a building, and as meeting the requirements of the Building Regulations.
Part L Requires the commissioning of fixed building services, which are defined as lighting, heating, domestic hot water, ventilation and air conditioning. Requirement L1b says that these should all be commissioned to ensure that they operate in an energy efficient manner.
Commissioning of buildings and building services is vital if they are to operate efficiently and effectively in accordance with the design intent. However, it is often not carried out – or carried out systematically. The CIBSE Commissioning Codes cover air systems, boilers, controls, lighting, refrigeration and water systems, all of which contain electrical components. Commissioning Code M provides an overarching guide to the management of the whole commissioning process to deliver integrated working systems. Code M presents current standards of good commissioning practice in the form of recommendations and guidance, and it is the approved method of demonstrating compliance with the commissioning requirement of Part L.
Code M may be used in a variety of contractual frameworks, and users need to ensure that its use is considered when contractual arrangements are being made, so as to ensure that the recommendations of the Code are not in conflict with those of the contract. In particular, it is important that contractual arrangements make due allowance for taking the needs of commissioning engineers into account during design stages, and that the construction phase allows adequate time properly to commission building services systems in full accordance with the requirements of Part L and the Code.
The CIBSE Lighting Commissioning Code covers lighting systems, which tend to be stand alone. It advises on the commissioning of internal lighting systems and their associated controls. Following this Code when commissioning lighting systems is an effective way of demonstrating compliance with the requirement to commission. Both Codes contain specimen commissioning completion certificates, which can be used to meet the requirement in the Building Regulations for the building control officer to receive a commissioning certificate.
A further requirement of Part L is the provision of sub meters. These should be installed to measure at least 90% of the energy going into a building by end use, so that the user has clear information about where the electrical energy is going in the building. CIBSE also produces guidance on the design and installation of sub meters, in CIBSE TM39, Building Energy Metering.
As the latest revisions of the regulations push new buildings to use less energy, there will be pressure on designers and installers of both new buildings and of major refurbishment works to select the most energy efficient electrical products, in order to achieve the targets required in the energy and carbon calculations for the building.
As yet only lighting products and fans have to meet the product specific ‘backstop’ minimum efficiency targets. But the Energy Related Products Directive is bringing in a wide range of minimum energy efficiency standards for all the energy uing electrical products that go into buildings (and a lot more besides!). E.g., no minimum target has been specified for electric ovens or motors. This requirement to select efficient electrical products will increasingly pass down the supply chain. Under the latest regulations, not only must the Target Emissions Rating and Building Emissions Rating be calculated, but when the plans are deposited the calculation and the specification on which it is based must also be deposited.
This opens up the prospect that if a building fails to achieve the BER required, and products have been substituted with alternatives of inferior energy efficiency, whoever made the substitution may find themselves held responsible for the building’s non compliance. This is a new departure, but one for contracts managers to watch carefully.
For non-domestic electrical products, designers, installers and procurement staff have to be careful in the final selection of the equipment.
In general, if a building can reduce electricity use it will meet the TER more easily. For non-domestic buildings, the following electrical products are likely to become more popular as they will help to reduce the emissions rating of the design:
Variable speed drives
High efficiency motors and pumps
High efficiency transformers
Equipment with smart energy controls
In addition, the following technologies may be considered, either to satisfy the carbon calculations, or to meet the demands of local planning policies:
Solar Photovoltaic
Biomass CHP
Heat pumps (air-source or ground-source)
Wind turbine
The new regulations bring risks if designers and installers do not have the professional capacity to design and deliver the building to the required standards, and there are compliance risks if suppliers or manufacturers over-state the capabilities of their products. This will give clients and other parties grounds for potential legal or contractual arguments.