Part L2
The implications for M&E firms of the revisions to Part L (2006) of the Building Regulations for Work in Buildings Other Than Dwellings (L2A & L2B)
Amendments to Part L of the Building Regulations (Conservation of fuel and power) were published on the 15th March 2006 and came into force in England and Wales on the 6th April 2006. The revisions to Part L introduce new energy efficiency requirements and have been revised as part of the government’s drive to reduce greenhouse gas emissions. One important way of achieving this is by minimising emissions from buildings.
The Building Regulations are made under the authority of the Building Act, which is rarely changed and defines both the scope of coverage of the Building Regulations and the legal framework for their implementation.
Part L of the Building Regulations has been divided into four sections and covers all buildings. Approved Document L2A covers new buildings other than dwellings, while L2B focuses on work carried out in existing buildings other than dwellings. Approved Documents L1A and L1B cover new and existing dwellings respectively.
Compliance with Part L can be demonstrated by meeting five criteria:
Criterion 1: The predicted building CO2 emission rate (BER) is not greater than the target (TER) in units of kgCO2/m2 per annum.
Criterion 2: The performance of the building fabric, heating hot water and lighting systems are no worse than design limits set out in the Approved Document.
Criterion 3: In those parts of the building not provided with active cooling, appropriate passive measures are included to prevent overheating.
Criterion 4: The performance of the building, as constructed, is consistent with the criteria made in the predicted BER.
Criterion 5: The information, which must be given to the building operator in order that the building may be run in an energy efficient manner, is defined.
The Part L Approved Documents cover the whole building design and construction process. This guidance focuses only on the new requirements for fixed electrical installation works (internal, electrical heating systems, control systems and metering) within the scope of the new Part L2A and L2B Approved Documents, and the implications for firms (electrical contractors) that carry out work in buildings other than dwellings.
Competent Person Scheme
The Electrical Contractors’ Association (ECA) has developed the Electrical Energy Efficiency Scheme for firms wanting to self-certify that the electrical installation work carried out in commercial and industrial buildings complies with Part L of the Building Regulations.
The scheme comprises three different scopes covering the following areas of work:
* Lighting Installations
* Electrical Heating Installations
* Controls and Energy Monitoring
Firms that are registered with an authorised Competent Person Scheme have the right to self-certify that their work complies with the Building Regulations. This means that any electrical installation work carried out within the scope of Part L does not have to be inspected by a building control body.
Clients that use a firm registered as a Competent Person have the reassurance that they are using a firm that has been independently inspected and certified as competent to carry out the work.
Further information on the Electrical Energy Efficiency Scheme is available at www.partl.co.uk.
Fixed electrical installation work means any part of, or any controls associated with:
a) fixed internal or external lighting installations, but does not include emergency escape lighting or specialist process lighting: or
b) electric heating or electric hot water service.
Building Regulations
The members of Competent Person Schemes that are able to self-certify their own work must have an appreciation of how the Building Regulations, in general, affect their electrical installation work and they need to be sufficiently competent to confirm that their work complies with all the applicable requirements.
Such requirements include, but are not limited to:
* Part A (structure) – depth of chases in walls and size of openings in joists or structural elements.
* Part B (fire safety) – fire resistance of ceilings and walls including provision of fire alarm and detection systems.
* Part C (site preparation and resistance to moisture) – moisture resistance of openings or penetrations for cables through external walls.
* Part E (resistance to the passage of sound) – penetrations through ceilings and walls.
* Part F (ventilation) – ventilation rates for areas within a dwelling.
* Part L (conservation of fuel and power) – energy efficient lighting, effective controls including automatic controls.
* Part M (access to and use of buildings) – heights of switches, socket-outlets, etc.
These approved documents may be downloaded free of charge from the Department for Communities and Local Government (DCLG) website at www.communities.gov.uk.
Enforcement
Failure to comply with the Building Regulations is a criminal offence and local authorities have the power to request the removal or alteration of completed work that does not comply with these requirements.
The person carrying out electrical work that contravenes the Building Regulations can be fined up to £5,000 for the contravention, and £50 each day the contravention continues. Householders may also encounter problems selling their property if work carried out does not comply with the Building Regulations.
Part L Requirement
The following section is quoted directly from the Regulations and Approved Documents. The Regulations under which the Approved Documents covering energy efficiency are issued read as follows:
Reasonable provision shall be made for the conservation of fuel and power in buildings by:
a. limiting heat gains and losses
i. through thermal elements and other parts of the building fabric;
ii. from pipes, ducts and vessels used for space heating, space cooling and hot water storage;
b. providing and commissioning energy efficient fixed building services with effective controls; and
c. providing to the owner sufficient information about the building, the fixed building services and their maintenance so that the building can be operated and maintained in such a manner as to use no more fuel and power than is reasonable in the circumstances.
Part L2A – New Buildings Other Than Dwellings
This Approved Document deals with the construction of new buildings other than dwellings; the first fit-out works in buildings that were built to comply with Part L as amended in 2006 (if the fit-out was deferred); and the construction of extensions to existing buildings where the gross floor area of the extension is greater than 100 m2 and greater than 25% of the gross floor area of the existing building. When a building contains dwellings, account should also be taken of Approved Documents:
* L1A – Conservation of fuel and power in new dwellings
* L1B – Conservation of fuel and power in existing dwellings
General lighting efficacy in office, industrial and storage areas in all building types
Office areas include those spaces that involve predominantly desk-based tasks, including classrooms, seminar rooms and conference rooms, including those in schools. (Note that schools are no longer exempt from the Building Regulations.)
Approved document L2A states that:
Reasonable provision would be to provide lighting with an average initial efficacy of not less than 45 luminaire-lumens/circuit-watt as averaged over the whole area of these types of space in the building.
The average luminaire-lumens/circuit-watt is calculated by:
(Lamp lumens x LOR) summed for all luminaires in the relevant areas of the building, divided by the total circuit-watts for all the luminaires where:
Lamp lumens = the sum of the average initial (100 hour) lumen output of all the lamp(s) in the luminaire and
LOR = the light output ratio of the luminaire, i.e. the ratio of the total light output under stated practical conditions to that of the lamp or lamps contained in the luminaire under reference conditions.
This is similar to the provision in the Part L 2002 edition except for the increased efficiency requirement from 40 to 45 Im/W and the removal of the luminaire control factor.
General lighting efficacy in all other types of space
The Approved Document recognises that for lighting systems serving other types of space, it may be appropriate to provide luminaires for which photometric data are not available and/or are lower powered and use less efficient lamps. For such spaces, the requirement would be met if the installed lighting has an average initial (100 hour) lamp plus ballast efficacy of not less than 50 lamp lumens per circuit-watt. This is again a similar approach to the Part L 2002 edition.
Lighting controls for general lighting in all types of spaces
Lighting controls should be provided so as to avoid unnecessary lighting during the times when daylight levels are adequate or when spaces are unoccupied. For safety reasons, automatically switched lighting systems should be subjected to risk assessment.
Reasonable provision would be local switches in easily accessible positions within each working area, or at boundaries between working areas, and general circulation routes that are manually operated by the deliberate action of the occupants. Manual switches include rocker switches, push buttons and pull cords and remote switching devices such as wireless transmitters and telephone handsets. ‘Switches’ includes dimmer switches and ‘switching’ includes dimming. It would usually be reasonable for dimming to be effected by reducing rather than diverting the energy supply. The distance on plan from any local switch to any luminaire it controls should generally be not more than six metres, or twice the height of the luminaire above the floor if this is greater. Where a space is a daylit space served by side windows, it would be reasonable for the perimeter row of luminaires to be separately switched.
Occupant control of local switching can be supplemented by other controls such as automatic systems which:
a) switch the lighting off when they sense the absence of occupants or
b) either dim or switch off the lighting when there is sufficient daylight.
An alternative way of meeting the requirement would be to follow the recommendations in BRE Digest 478 Selecting lighting controls, 2006. The main differences from the Part L 2002 edition are that the maximum distance from manual switches to the luminaires they control has been reduced and that there is no control factor.
Display lighting in all types of space
Reasonable provision for display lighting would be to demonstrate that the installed display lighting has an average initial (100 hour) efficacy of not less than 15 lamp-lumens per circuit-watt. In calculating this efficacy, the power consumed by any transformers or ballasts should be taken into account. This will rule out GLS lamps but allow most types of tungsten-halogen lamp. Spaces where display is present would normally be expected to also have general lighting used for circulations and for purposes of cleaning and restocking outside public access hours. The above lighting paragraphs apply in this case.
Controls for display lighting in all types of space
A way of meeting the requirement would be to connect display lighting in dedicated circuits that can be switched off at times when people will not be inspecting exhibits or merchandise or attending entertainment events. In a retail store, for example, this could include timers that switch the display lighting off outside store opening hours, except for displays designed to be viewed from outside the building through display windows.
Systems not covered by Part L
Emergency escape lighting, specialist process lighting and vertical transportation systems are not subject to the requirements of Part L.
Electrical Space Heating and Hot Water Heaters
Guidance given in this section covers the following types of electrical heating installations, which may be used to provide primary or secondary space heating in buildings other than dwellings:
* Electrical boilers for central heating systems
* Electrical panel heaters
* Electrical warm air heaters
* Electrical storage heaters
* Electrical fan, convector and radiant heaters
* Electrical underfloor heating systems
The following electrical hot water heaters systems covered are:
* Point of use electrically heated water heater systems
* Instantaneous electrically heated water heater systems
* Local electrically heated water heater systems
* Centralised electrically heated water heater systems
Reasonable provision for the performance of heating and hot water system(s) would be:
a. the use of an appliance with an efficiency not less than that recommended for its type in Non Domestic Heating, Cooling and Ventilation Compliance Guide; and
b. the provision of controls that meet the minimum control requirements as given in the Non Domestic Heating, Cooling and Ventilation Compliance Guide for the particular type of appliance and heat distribution system.
Commissioning of Heating and Hot Water Systems
The heating and hot water system(s) should be commissioned so that, on completion, the system(s) and their controls are left in the intended working order and can operate efficiently for the purposes of the conservation of fuel and power. In order to demonstrate that the heating and hot water systems have been adequately commissioned, Regulation 20C states that:
1) This regulation applies to building work in relation to which paragraph L1(b) of Schedule 1 imposes a requirement, but does not apply where the work consists only of work described in Schedule 2B.
2) Where this regulation applies the person carrying out the work shall, for the purpose of ensuring compliance with paragraph L1(b) of Schedule 1, give to the local authority a notice confirming that the fixed building services have been commissioned in accordance with a procedure approved by the Secretary of State.
3) The notice shall be given to the local authority:
a. not later than the date on which the notice required by regulation 15(4) is required to be given; or
b. where that regulation does not apply, not more than 30 days after completion of the work.
Controls and Energy Metering
Systems should be provided with appropriate controls to enable the achievement of reasonable standards of energy efficiency in use. In normal circumstances, the following features would be appropriate for lighting, heating, ventilation and air conditioning system controls:
c. The systems should be subdivided into separate control zones to correspond with each area of the building that has a significantly different solar exposure, or pattern, or type of use; and
d. Each separate control zone should be capable of independent timing, and temperature control and, where appropriate, ventilation and air recirculation rate; and
e. The provision of service should respond to the requirements of the space it serves. If both heating and cooling are provided, they should be controlled so as not to operate simultaneously; and
f. Central plant should only operate as and when the zone systems require it. The default condition should be off.
In addition to these general control provisions, the systems should meet specific control and efficiency standards as set out in the Approved Document.
Energy Meters and Monitoring
Reasonable provision for energy meters would be to install energy metering systems that enable:
a. at least 90% of the estimated annual energy consumption of each fuel to be assigned to the various end-use categories (heating, lighting, etc.). Detailed guidance on how this can be achieved is given in CIBSE TM39; and
b. the performance of any Low and Zero Carbon (LZC) energy source systems are to be separately monitored; and
c. in buildings with a total useful floor area greater than 1,000m2, automatic meter reading and data collection facilities.
Ideally, all energy consumption should be directly metered, but this is not always practical or cost effective. With this in mind, the Building Regulations ask for at least 90% of each incoming energy to be accounted for through the use of metering. The Regulations also allow various estimation methods to be used where direct metering is impractical. This allows you the flexibility to mix and match in order to:
a) overcome practical installation problems.
b) optimise capital and installation costs.
c) integrate metering into the services as they are designed.
d) ensure that operators have a practical method of establishing an audit of energy use.
Commissioning
The building services systems should be commissioned so that, on completion, the system(s) and their controls are left in working order and can operate efficiently for the purposes of the conservation of fuel and power. Regulation 20C states that:
1. This regulation applies to building work in relation to which paragraph L1(b) of Schedule 1 imposes a requirement, but does not apply where the work consists only of work described in Schedule 2B.
2. Where this regulation applies, the person carrying out the work shall, for the purpose of ensuring compliance with paragraph L1(b) of Schedule 1, give to the local authority a notice confirming that the fixed building services have been commissioned in accordance with a procedure approved by the Secretary of State.
3. The notice shall be given to the local authority:
a) not later than the date on which the notice required by regulation 15(4) is required to be given; or
b) where that regulation does not apply, not more than 30 days after completion of the work.
Schedule 1 is to be found in SI 2531 of 2000. L1B is simply a reference to ‘controlling the operation of the space heating and hot water systems’.
Schedule 2B is to be found in SI 3210 of 2004, and is the list of work that need not be notified under the Part P Scheme.
Reg 15(4) is to be found in SI 2531 of 2000. It calls for notification to the Building Control body within 5 days of completion of the work.
Building Log-Book
In accordance with Requirement L1(c), the owner of the building should be provided with sufficient information about the building, the fixed building services and their maintenance requirements so that the building can be operated in such a manner as to use no more fuel and power than is reasonable in the circumstances.
A way of showing compliance would be to produce information following the guidance in CIBSE TM31 Building Logbook Toolkit. The information should be presented in templates as or similar to those in the TM. The information could draw on or refer to information available as part of other documentation, such as the Operation and Maintenance Manuals and the Health and Safety file required by the CDM Regulations.
Checklists
The checklist prompts for the evidence that needs to be provided to allow the check to be made, and who could produce the evidence. For most steps, the evidence could be provided by an approved Competent Person, or a suitable qualified person acting for the developer, and may be accepted at face value at the discretion of the Building Control Body dependent upon the credentials of the person making the declaration.
In the checklist, the ‘Produced by’ column indicates the expected source of the evidence, and the header and footer blocks of the checklist allow opportunity for the credentials of those submitting the evidence to be declared. If the evidence is not produced by an approved Competent Person, Building Control Bodies have the discretion to accept evidence from other groups of appropriately qualified and/or experienced individuals.
Electronic versions of the compliance checklist can be downloaded from the DCLG website www.communities.gov.uk.
Part L2B – Work Within Existing Buildings Other Than Dwellings
There are exclusions to what counts as an existing building, e.g. where the proposed extension has a total floor area that is both:
a) greater than 100 m2; and
b) greater than 25% of the floor area of the existing building
then the work should be regarded as in a new building and Approved Document L2A should be followed.
Where there is a material change of use, the building or part of a building should comply with the applicable requirements of various Parts of Schedule 1, including Part L. Specific requirements apply to the provision or extension of controlled services.
Regulation 17 requires “consequential improvements” to improve the energy efficiency of the whole building when there is an extension or alteration of over 100 m2. For lighting, it is considered that reasonable provision for consequential improvements would be, for any general lighting system serving an area greater than 100m2 and which has an average lamp efficacy of less than 40 lamp-lumens per circuit-watt (i.e. below the standard in the Part L 2002 edition of Approved Document L2), to upgrade it by the provision of new luminaires or improved controls.
General Lighting
The efficiency criteria are generally the same as the “fall-back” criteria for new buildings, i.e. 45 luminaire-lumens per circuit-watt for offices, industrial and storage areas, 50 lamp lumens per circuit-watt in other types of space, and 15 lamp lumens per circuit-watt for display lighting along with requirements for controls, with the addition of a control factor (see below).
The average luminaire-lumens/circuit-watt is calculated by:
(Lamp lumens x LOR) summed for all luminaires in the relevant areas of the building, divided by the total (circuit-watts x control factor) for all the luminaires where
Lamp lumens = the sum of the average initial (100 hour) lumen output of all the lamp(s) in the luminaire and
LOR = the light output ratio of the luminaire, which means the ratio of the total light output of a luminaire under stated practical conditions to that of the lamp or lamps contained in the luminaire under reference conditions.
Control Factor
Unlike the requirements for new buildings, those in Approved Document L2B still include a controls factor defined as the factor applicable when automatic controls substantially reduce the power consumption of the luminaire when electric light is not required. The control factor is stated to have been included in Approved Document L2B to allow greater flexibility and to encourage better controls.
Commissioning
The building services systems should be commissioned so that, on completion, the system(s) and their controls are left in working order and can operate efficiently for the purposes of the conservation of fuel and power. Regulation 20C states that:
This regulation applies to building work in relation to which paragraph L1(b) of Schedule 1 imposes a requirement, but does not apply where the work consists only of work described in Schedule 2B.
Where this regulation applies, the person carrying out the work shall, for the purpose of ensuring compliance with paragraph L1(b) of Schedule 1, give to the local authority a notice confirming that the fixed building services have been commissioned in accordance with a procedure approved by the Secretary of State.
he notice shall be given to the local authority:
not later than the date on which the notice required by regulation 15(4) is required to be given; or
where that regulation does not apply, not more than 30 days after completion of the work.
Building Log-Book
In accordance with Requirement L1(c), the owner of the building should be provided with sufficient information about the building, the fixed building services and their maintenance requirements so that the building can be operated in such a manner as to use no more fuel and power than is reasonable in the circumstances.
A way of showing compliance would be to produce information following the guidance in CIBSE TM31 Building Logbook Toolkit. The information should be presented in templates as or similar to those in the TM. The information could draw on or refer to information available as part of other documentation, such as the Operation and Maintenance Manuals and the Health and Safety file required by the CDM Regulations.
Checklists
Similar to L2A requirements.
Useful Websites
Electrical Energy Efficiency Scheme www.partl.co.uk
Department for Communities and Local Government www.communities.gov.uk
Local Authority Building Control www.labc.co.uk
The Carbon Trust www.thecarbontrust.org.uk
Energy Technology List www.eca.gov.uk/etl/
Buying Solutions www.ogcbuyingsolutions.gov.uk
Environment Agency www.environment-agency.gov.uk
NetRegs www.environment-agency.gov.uk/netregs
Defra www.defra.gov.uk