Chris 1, I am super impressed. It’s really quite a thing. Radiused plastering too . . . .
Should anyone else be tempted, I’ve found that much can be achieved with just a hole under the floor. OK, when does a hole become a cellar? Perhaps when it has a reasonable head height?
I have such a hole under my kitchen floor. From the underside of the floor joists it’s 3’ deep and came about when, needing to supply water to a sprinkler system for the house, I had to put a tank and pump somewhere. Underground seemed the obvious choice, so why not make the hole a bit bigger & store wine down there too? The basic rule is that when you dig in (or around) your house you should not go within a line that runs at 45 degrees out from the bottom of the foundations of any adjacent walls. Breaking the rule obviously happens but could then need proper calculations & engineering to keep your house standing.
I’ll not say much about construction methods as you may prefer to read about bottles & the stuff therein. Suffice to say, Hole is rectangular, has a ventilation pipe & a concrete slab floor like Chris 1’s. It’s lined with heavy duty polythene and the walls are made from concrete blocks laid on the flat (ie they are thick & thus strong). All painted with grey floor paint.
Temperature is constant enough, there’s no damp and there’s racking for circa 125 bottles, which is plenty for me now, plus space for about 5 doz in cases. Were I to have 5 doz in cases . . . The upper rows are accessible when kneeling by the open hatch. Climb down for the rest. In summer this can be rather a cooling experience, so I have found myself down there for longer than might be thought necessary to select a bottle.
OK, you’re not going to go at your floor with pick & shovel any old day of the week, but if you have works being done to your ground floor, then you could consider something quite shallow. 3’6”ish seems to be deep enough to get a cool temperature, in London clay at least, and there’s less chance of hitting the water table. You’d be able to have racking for circa 250 bottles in a 4’6” x 4’3” x 3’0” deep hole.