why have all the sockets and spurs on one 20 a breaker
It would be better on either two or more circuits if you have the consumer unit shown in the drawing and spare ways!
Although the wiring shown is possibly within the regs , it is not good practice,
Try to stick to a proper radial circuit a ring or more circuits rather than branching off, At what i assume will be a joint ,as it is in the middle of nowhere
Pvc conduit would be easier for you rather than metal conduit
It would be better on either two or more circuits if you have the consumer unit shown in the drawing and spare ways!
Although the wiring shown is possibly within the regs , it is not good practice,
Try to stick to a proper radial circuit a ring or more circuits rather than branching off, At what i assume will be a joint ,as it is in the middle of nowhere
Pvc conduit would be easier for you rather than metal conduit