Building regs for an outbuilding?

[Cushionandpillow]

Off the back of another thread I thought I would ask more knowledgeable mumsnetters!
I recently purchased a house that has an outbuilding at the bottom of the garden which I was planning on converting into an office in the summer. The outbuilding is also attached onto next doors outbuilding so width wise it goes from one end of the garden to the other. I’m assuming this used to be the outside toilet as it has water and electric to it, so it has been built a good while! Would I need building regs for the building?
When I bought the house I never thought of building regs for this building but now actually thinking about it, it makes sense!
Any help would be appreciated
Thank you

My understanding is that you would only require building regs approval if you were going to materially change the use and put in sleeping accommodation and so make it residential.

As long as no one is going to be sleeping there then you don't need to worry.

Although if you were to knock it down and construct an entirely new outbuilding then you would have to consider whether you would need building regs approval or not.

So, probably easiest to just convert it and repair if necessary rather than thinking about knocking it down and building from scratch.

www.planningportal.co.uk/info/200130/common_projects/43/outbuildings/2

When you say ‘convert to an office’ , what work are you planning on doing?

That is very helpful thank you @Loofah01

@tanstaafl I was just thinking along the lines of getting it properly insulated having the electrics rewired so they safe, putting in a small kitchenette and a desk and using it as a place I can work in relative peace. I was also thinking that if I wanted to sell my house a few years down the line the building could have multiple uses for any new buyers but from reading up on this I would need building regulations for it to be used as a bedroom

@tanstaafl sorry it also needs a new roof, it is basically just a shell at the moment

You would need br for it to become a habitable room,

Assume this is a brick ‘outhouse’ from your OP.
You want to convert an outside toilet then?

I mean go ahead but just how much internal space is there ?