The ABC (and not forgetting P) of Building Regulations
Release Date: 31/10/2012
The ECA’s Richard Giddings and Giuliano Digilio summarise the sign-off process of electrical work in dwellings required under Part P, and outline the ‘other’ associated building regulation issues that contractors need to be mindful of.
‘Part P’ makes it a legal requirement to protect installers and users of typical domestic dwellings from fire and injury risks arising from the electrical installation.
Likewise, it defines ‘notifiable work’ regarding electrical installations that either need approval and sign off by the Local Authority Building Control, or, more commonly, ‘self-certification’ by a contractor registered with a Part P Competent Person Scheme, such as ELECSA.
It is also worth considering the sign off process and implications on the contractor when notifying work – particularly regarding the ‘other’ relevant building regulations.
Whichever method of sign-off is used, the overall declaration is that the work is ‘in compliance with regulations 4 and 7 of the building regulations 2000’ that says ‘all work covered by the sign off meets all of the requirements of the building regulations in total, as well as Approved Document P (and usually hence BS7671) and has been installed using good workmanship and materials’.
The process can be likened to a vehicle MOT. It is an ‘all or nothing’ situation to avoid making ‘false declarations’ under the statutory Building Regulations.
Building Regulations, just like BS7671 (the IET wiring regulations), continue to evolve and it is essential that organisations signing off their work through self certification continue to keep up to date with new requirements.
Because publications advising on the building regulations are not always current, competent person scheme assessments often discuss Building Regulation issues – and assessors should highlight any changes relevant to the job.
By following the guidance given in the Approved Documents (and in some cases second tier documents), a solution considered to meet Sections 4 and 7 of the Building Regulations may be achieved.
Approved Document A – Structure (2010) – This considers the potential weakening or overloading of a structure, that may occur when cutting away fabric of a building, or adding equipment as part of an electrical installation.
Most relevant is guidance given on maximum hole sizes in traditional softwood joists together with chase depths in walls – both of which are capable of weakening an existing structure to point of failure.
Additionally, with the growth in solar PV installations, the loading on existing roof structures sometimes needs to be considered.
Approved Document B – Fire safety - This section is split into several sections – the most relevant to dwellings being: Approved Document B – Fire Safety – Volume 1 – Dwellings (2010) and include issues such as fire detection and alarm systems, fire resistance of ceilings and wall linings including lighting diffusers and the fire resistance of openings and penetrations through building fabrics.
Guidance is given on the specifications for fire detection systems, their power supplies, considerations when cutting into wall or ceiling linings, and the sealing of penetrations into fire resisting building components.
Approved Document C – site preparation and resistance to contaminants
and moisture (2004) Practical areas of interest covered include the need to seal where cables enter building, perhaps through an external wall to prevent water entry.
Similar considerations would also be needed inside, to prevent moisture laden air from kitchens or bathrooms travelling to other rooms and leading to deterioration of the building fabric.
Approved Document E - Resistance to the passage of sound (2010) - In terms of practical issues for electrical contractors, consideration needs to be given regarding how noise may be transferred between gaps and openings, service ducts and risers.
It is most relevant (and rigorously enforced) in buildings that contain multiple occupancies such as flats and apartments, or indeed linked properties.
Practical issues to watch for include the sealing of any gaps or sound passages, and recognising that in some instances, typical materials used by other trades to limit sound transfer, such as glass fibre insulation, will of course also act as a heat insulator – which in turn imposes electrical issues on any cables in those areas.
Approved Document F – Ventilation (2010) - sets out the requirements for ventilation in buildings including positioning of standalone extractor fans in bathrooms and kitchens that often form part of a typical electrical contract. A new area covered in the 2010 version of this document, and its accompanying ‘Domestic Ventilation Compliance Guide’ - 2010 is the requirement to test performance because installing it under certain conditions, perhaps utilising ductwork, or fitting it into modern airtight building, may reduce the performance.
Approved Document L1A & L1B – Conservation of fuel and power (2010) These set out the requirements for energy efficient lighting and heating controls. Since the 2005 introduction of Part P, Approved Document L1 has been updated three times.
L1A covers new dwellings, with L1B relating to existing dwellings undergoing refurbishment or re-wiring. Both documents now refer to common guidance given in the second tier document ‘Domestic Building Services Compliance Guide’ – 2011.
Approved Document M - Access to & usage of buildings (2010) - This sets out the requirements for buildings to be easy to access and use by all - not just persons with disabilities. The most common requirements, involve heights of switches and sockets, and specific guidance is given of locating such wiring accessories between 450mm and 1200mm above finished floor levels in new dwellings.
Whilst Approved Document P is primarily concerned with electrical safety, it is the sign off or ‘notification’ process that implicates self-certifying contractors in compliance with the other areas of the Building Regulations affecting their work.
All of the Approved Documents as well as the ‘second tier documents’ can be downloaded from: www.planningportal.gov.uk/buildingregulations/ approveddocuments