Christian McArdle wrote:
House to Garage = 8m
Garage to Shed = 6m
Shed to Summerhouse = 5m


There are lots of ways you could do this. I'd run 6mm 2 core SWA from the
house to the garage, with a 32A Type B MCB in the house.

At the garage, I'd have:
30mA RCD for the entire lot. Isolate the earth from the house. Do not
connect to the garage. Use an earth rod.
6A MCB for the lighting
16/20A MCB for the sockets (you can go up to 32A if you wish)
16A MCB for the shed/summer house

Then 3 core 2.5mm SWA, exporting the garage earth down one core, from there
to the shed and summer house. Run shed/summer house lighting from local 3A
FCUs if the fittings do not indicate compatibility with a 16A circuit.

Don't forget that you will need to notify the council and have the
installation tested.

Note that your proposed spotlights for your garage might not be a good idea.
Spotlights are appalling inefficient for space lighting and contribute
significantly to global warming.

Christian.



Why the earth rod for shed? would you like to quote a reg to justify it
please.
My preferred way would be 5 way consumer unit in garage rcd sockets
where nessary, no rcd protection to server (to prevent nusicence
tripping) agree with all mcb/cable sizes but would put small 2way
"garage consumer units" with rcd main switch in shed and summer house