I have exactly the same problem with bags of compost - I need to take the barrow the long way round the terrace of houses, and another row of homes, and across the green space behind to get to my back garden. Two bags compost for the potatoes, and four bags topsoil to build up beds, mixed with local clay and mushroom compost. Alternatively, I could use a suitcase trolley to take them one at a time through the house, but I'm not sure it's strong enough. I can move some of my own soil around a bit. I'm going to dig a deep hole to put the old cold water tank in to collect rain from the flagstones. (I don't have a downpipe for a water butt). And dig out a bit of the raised part of the garden to put in a step. Not today, though.

Didn't click on the conflict between bed, mattress etc, and bed, soil! Sorry!