Don't worry too much about sunshine reaching the back row - you are going to have an interesting time trying to keep the front row lower, anyway. I think the warmth is as important as sun, and most raspberries can cope quite happily with a bit of shade, anyway.

How 'limited' is this space? You will need a space between the rows in order to harvest the raspberries.

Instead of planting in rows, try diagonals, or zig zags might be a better description, so that each plant has access to the light, rather than being hidden behind in trench type lines.

My autumn bliss, as an example, have a 2msq plot with one in each corner and one in the middle. All off-shoots and side shoots are removed.

Moon Growe is right about access - something we all tend to forget about until harvesting time!

You've got a point there, Mg, maybe just one row would be more effective, unless you plant the rows close together and harvest from the front and back! Raspberries can grow really tall, and quite bushy, too, and pushing your way through between canes can seem a bit like jungle warfare!

We had to take out one row of our canes as even at 18 inches apart it was a challenge to get between them and, yes they were pruned to just over 5 foot and tied into wires. It isn't the fruiting canes but the new ones which grow slightly in front of or behind the existing cane.

Moongrower,gattina Avkq47 thanks for your comments-like the idea of diagonal line and I will bear in mind spaces between the rows.