Where abouts in the u.k is this tool shed ?? .. I'll come keep it warm , CFL is fine for me , not growing for profit or to never have to buy it again lol simply for the love of the plant , 1 at a time , endless choice of strain , few nice treats a year of a strain I know is true and of my choice ..

your not the first to question the shed lol
Well then fair enough, but keep in mind the length of the grow also.
It can be off putting waiting so long & only getting a little.
I'd usually grow 32 ladies, pulling me a slightly dangerous Amount every 4 months & taking into consideration "Johnny law" as I call it, but I'm a pretty heavy smoker & around here you either grow your own or buy some of the most expensive lowest quality you've ever smoked.
Jamican reggie would be an improvment.
Shoot for around an oz per plant, but you'll need to watch PH, use quality nutes, your grow medium, environment (co2) (air), etc.
If you improve the light, you'll probably double your yield.
Sorry, I'm baked & rambling.