Rule breaker, risk taker

When it comes to mounting consumer units, Part P and Part M of the Building Regulations have left many in the industry confused.

Traditionally, the consumer unit is positioned either high up on the wall out of eye line, in the downstairs toilet or perhaps in a cupboard under the stairs. Judging by much of the new build that we see, most people clearly still believe that this is where it should stay.

Unfortunately this does not meet with the requirements of either Part P or Part M. In fairness the legislation is hardly clear on the matter.

Part P section 1.6 states that: “Wall-mounted socket outlets, switches and consumer units should be located so that they are easily reachable where this is necessary to comply with Part M. Approved Document M shows ways of complying.”

This seems to be clear enough. Unfortunately, if you then refer to Part M, there is no overt mention of consumer units, hence the muddied waters. Here you need to dig deep, and it is probably not a surprise that few bother. If you want to comply with the Building Regulations, however, you must.

Section 8 of Approved Document M, which applies to new dwellings, includes the objective of “assisting people whose reach is limited to use the dwelling more easily, by locating wall-mounted switches, socket outlets and other equipment at suitable heights, so that they are easily reachable for use.”

The NICEIC indicates that “other equipment” includes circuit breakers and therefore the consumer units that they are sited in.

Suitable heights for switches and socket outlets are between 0·45 m and 1·2 m from the finished floor level.

However, a more limited height range of 0·75 m to 1·2 m above finished floor level is recommended for simple push button controls, isolator switches and circuit breakers that require limited dexterity. So the maximum height should be 1200 mm to the centre of the switches and controls. If you are using a multi-row enclosure, then all the devices must be within these height ranges.

In fairness, this clearly complies with the spirit of Part M. Consumer units should be accessible so that people can operate circuit breakers in an emergency and for the routine testing and resetting of RCDs. This means that they must be in reach as defined by Part M.

It is time for the industry to be aware of all Part M requirements

In addition, they should not be installed in a lockable cupboard – which is, after all, hardly accessible. Any consumer unit that complies with BS EN 60439-3 and has switches that are located behind a cover is fit for purpose.

The NICEIC also makes the point that consumer units must be accessible for safe working. Regulation 15 of the Electricity at Work Regulations 1989 states that to avoid injury “…adequate working space, adequate means of access and adequate lighting shall be provided at all electrical equipment on which, or near which, work is being done in circumstances which may give rise to danger.”

For a consumer unit, such work should include the measurement of maximum prospective fault current, a test that may give rise to danger. It should therefore be mounted at a height that allows adequate access for such work to be carried out safely.

Mounting a consumer unit at a suitable height for inspection, testing and maintenance is also necessary for compliance with the accessibility requirements of Regulations 131-12-01 and 513-01-01 of BS 7671.

You will note that this article only refers to new build. You do not need to move a consumer unit to Part M heights for a house rewire or for building an extension. It might, however, be considered best practice to do so.

One final point, if a consumer units is fitted in the garage, then it must also comply with Part P and Part M. You should choose a position where it’s unlikely to be damaged. Back walls are generally better than side walls.

It is time for the industry to be aware of all Part M requirements and to at least draw the main contractor’s attention to its legal obligations. The fact that this might cause some builders inconvenience is not an argument.

Arguments about aesthetics are not a barrier to complying with the regulations. Indeed, many boards have modern aesthetic designs. If a board sticking out of the wall will cause a hazard then install a flush fit unit.

Many of the issues which are currently surrounding Part M are due to be clarified by the end of this year. In the meantime, make sure that you at least draw attention to the regulations.

According to one recent blog, an electrician told the NICEIC inspector who rejected a consumer unit installation to shove Part M. While this may have been satisfying, it carries no legal weight.