Is a Part P cert required for electrics to garden studio?

All domestic electrical work must comply with Part P of the Building Regulations. There are certain works that also require notification to the Local Authority Building Control (LABC) office. The work to your studio IS notifiable . The problem with all this Part P is, it is abused. If your electrician is registered with a competent person scheme (CPS) such as NICEIC, NAPIT, Stroma et al then he would be allowed to self-certify his work under Part P and he would inform them when he completes the job and the CPS would notify the LABC. If he isn't a member he has already broken the Law by not informing you about this. It is YOUR responsibility to tell the LABC not his. Its a Building Regulation not an Wiring Regulation requirement. Unfortunately nobody is enforcing Part P so it is a free for all and open to abuse. Not a lot you can do I'm afraid. The LABC don't get involved and if the electrician is not a member of a CPC there is little you can do to get the Part P approval. Incredibly Part P has been in force since January 2005, 16 years!! You would think it would have been sorted out by now. Good luck with your 'electrician'. Contractually your builder is responsible as well. He has sub-contracted the work so you have no contractual relationship directly with the electrician. Messy one but not uncommon.

A garden offices electrics need to comply with Part P of the Building Regulations. It is a legal requirement that a qualified electrician undertakes any domestic electrical work, and this includes connecting the electrical system of your garden office to your house's mains SUPPLY.

Agreed with all the above. I would ask your "electrician" if he is registered with a Competent Person Scheme so as to certify/notify the works. If he isnt, then you need to take it up with your builder. But it certainly DOES need Building regs notification & certification.