I hope someone can help me with advice on the positioning of a consumer unit in a retail outlet (non public area), I am aware of plenty of guidelines regarding domestic premises. Can someone point me in the direction of some definitive guidelines – Non Domestic. I have seen a consumer unit positioned at the top of a stairway on a small landing, a step ladder is needed to access it. In my opinion this is unsafe, I would appreciate some technical guidelines to support my argument, as there are also third party contractual issues present.

Gashead, You are on about an electrical distribution board? Nick has covered gas metering, which is slightly different. Firstly your designer has a statute law duty to work to CDM requirements. Look at the requirements of CDM, and see if your top of a stairwell example with a ladder is acceptable?... It must be secure from tampering and incompetent access to comply with EAWR89, EN60439-3/61439-3 distribution boards are suitable for use by unskilled persons, however, you would not want them accessible to the general public, I do note you say it's in a staff-only area. It must be accessible so that it meets the maintainability requirements of CDM Reg 9 & EAWR Reg 15 So this takes us to the WAH regs and the hierarchy of control for WAH. 1. Don't do it. So to comply with statute law the designer of the installation must place the distribution board at a height such that there is no requirement for WAH. QED. If you want more look to BS7671 Reg 341.1, 132.12, 513.1, 529.3 (this is a good one!). A distribution board must be accessible for both live & dead testing, along with routine operation for isolation and re-energising circuits, thus, it can be considered that working on or near it may give rise to danger, thus, you must minimise this danger, so, remove the hazard of working at height first as it’s easy to do! If the designers of your electrical installation don't understand these simple requirements of statute law, & BS7671, then you need to find new designers! ;) You won’t find a height for it like you will under Part M. It is the designers statute law duty to minimise the dangers from maintenance, AFARP, and it is easy & cheap to design out the risk of WAH at the design stage, thus there is no economic reason not to design it out. Look also to BS8300, and, you are free to specify whatever you like when you go to tender, as long as what you specify would not result in a breach of statute law, or I suspect, BS’s & accepted industry practice in making it less safe.