Whilst contemplating the delivery of a hot tub I reckoned it would be a good idea to put a small cover around it to keep the lovely English howling gales and rain out so along came the idea for a shed. On the way it gained a sauna (nearly burnt the hut down with that one), shower/basin/WC (so as not to be caught short), cat 5, telephone, TV with Sky (great for watching recent sporting events with a cold beer in the tub), alarm system (keep the buggers out), a second floor (so you can have a bit of a kip), a nice veranda for dining and drinking outside on those frequent hot summers evenings (like that will happen now), and there is a lovely space for the hot tub to fit in.
Took a bit of work installing the armoured cable and distribution box but still not as hard as digging the trench for the soil pipe which incedentaly broke the water main (gave me a good excuse for the supply for the shed).