The UK Water Regulations make it illegal for plumbers to connect bidet devices that are the ascending spray type, or that have a flexible hose, directly to the mains water supply. Such bidets are usually foreign imports, and even though you can easily buy them in the UK, they are not made with UK water regulations compliance in mind. In the UK, there are only two ways you can install them legally:

1) Connect them to a gravity feed from a header tank. However, in most cases this is not practical, especially in houses with a combi boiler, or pressurised hot cylinder, that do not already have a header tank.

2) Connect them to the mains supply via a Type DC pipe interrupter for fluid category 5. British manufacturer, Dudley, supply one of these that is really intended for use in urinals. It could potentially be used for a bidet spray, but it would need to be fitted well above the toilet near ceiling level to give sufficient pressure. So again, this is not a very practical solution for a bidet, and the pipework required would be somewhat unsightly.

In practice, most handheld bidets sprays present in UK homes have been installed illegally. As a professional plumber, I choose to stay within the law.

The UK Water Regulations expect bidets to be the over-rim type, such that the spout is at least 20mm above the spillover level of the bowl, such as in this photo. A bidet is therefore an option to think about when you are redesigning your bathroom, but is not an easy thing to add to an existing bathroom.

If you need a bidet facility for religious or cultural reasons, the most practical legal solution is to use a jug and to fill it from the basin tap before you use the toilet.