There are two opposing images in my mind when I think about roof gardens. The first is a green, high-rise urban oasis, a feeding platform for bees and a foil for smog and the stresses of city life. The second is of a baking windswept space for which you have to spill your wine climbing 3 flights of stairs to ‘enjoy’.

Roof gardens can go so wrong, I think usually for lack of thought and effort. Badly-finished decking squares, shrively pot plants, wobbly trellis screens. And London lags behind other western cities in its exploitation of these valuable spaces, while New Yorkers get green roof tax breaks. Commit, people! Design your roof terrace for practical and pretty and you’ll get a deeper tan and a higher-value property; an average 10-15% higher, according to estate agents.

And the range of styles and plants are surprisingly broad. Roof gardens can be chic viewing platforms to the city which offer the comfort and style of the owner or, with dense planting, candlelight and vertical structures, have an altogether more intimate, inward-focused spaces.

With the right containers and care grasses, veg, even sizeable trees can add height, shade, lunch or privacy. Stick a small drinks fridge up there and even the spilled wine isn’t a problem.

Which would you choose?