This guide covers England, where Croydon is. Building regulations set minimum standards for safety, health and energy use. They’re separate from planning permission, which is about how buildings look and what they’re used for, and from any consent your lease requires.
The short answer
According to the Planning Portal, refitting a bathroom with new units and fittings does not generally require building regulations approval, although drainage or electrical work might. In practice, that means looking at four things.
1. Electrics (Part P)
A room containing a bath or shower is a “special location” under Approved Document P. In England these jobs are notifiable:
- Installing a new circuit, for example for an electric shower or underfloor heating
- Replacing the consumer unit (fuse box)
- Any addition or alteration to circuits in the bathroom itself
Notifiable doesn’t mean a separate application from you. An electrician registered with a competent person scheme self-certifies the work and you receive a certificate. Keep it: you’ll need it when you sell.
Bathroom zones
2. Ventilation (Part F)
Approved Document F sets a minimum extract rate for bathrooms of 15 litres per second for a fan that runs when the room’s in use. A window that opens isn’t a substitute. A new or replacement fan should meet that rate, be ducted to the outside, and in a room without a window, carry on running for a while after you leave.
3. Drainage
Swapping a toilet or basin in the same place is fine. Moving the toilet, adding a new soil connection or altering the soil stack is drainage work that can need building control involvement. A new toilet needs a waste with enough fall, and in an internal room, a way of venting it.
4. Structure
Removing or making an opening in a loadbearing wall, or cutting into floor joists more than the regulations allow, needs approval. A typical example is knocking the separate toilet into the bathroom in a 1930s semi: often the wall is a lightweight partition, but not always.
Planning permission
Internal changes to an ordinary house don’t need planning permission. Exceptions:
- Listed buildings need listed building consent for internal alterations
- Extensions to create a new bathroom may need planning permission
- Leasehold flats need whatever your lease requires, which is separate from planning. See our leasehold guide
Who sorts it out?
You’re responsible for making sure the work complies, but in practice the people doing it handle the paperwork. For the work we do, we arrange the electrical certification and any notifications needed, and tell you up front if a part of your job needs building control involvement.