New garden office, Cable selection and method...?

[malcolmsanford]

You won't be able to get a 3 core 10mm T+E though.

Can I ask if your an electrician?. Because as I mentioned in post #14 you may find the 4mm CPC is good enough, but you need to do the adiabatic equation to make sure

 

[RISElectrical]

3 core and earth? You would just need the 10mm T+E and then a separate 10mm earth. Basically just ensure that the size of the earth is always at 10mm for the whole run. If that makes sense