building regs ?

Can someone help me to find a building regulation regarding running water in a bathroom.

The story being a combi boiler has been fitted in a property with out checking the water flow rates to the property. When the washing machine is on or the downstairs tap is turned on there is no water supply to the bathroom. Meaning if some uses the toilet they can not wash their hands or run a bath.

Was wanted a Building regulation section number

many thanks

There isn't one. B/regs don't cover this situation

It sounds like the combi system has been either poorly installed or is undersized & presumably you’re trying to get it fixed! Although there is no Building Regulation covering this, it should have been highlighted as a result of standard pre installation checks which I’m sure will be covered under points of good practice for the plumbing & heating trades. Try a new post in the central heating & plumbing forum; I’m sure one of the gurus on there will advise on the best way to proceed & if the culprit is registered with one of the plumbing trade associations, they may also be able to help.