I assume as you say 'grow against' that you don't want a climber. I have Garrya elliptica on a North wall of the house. This is evergreen (grey-green leaves) and from now til well into the New Year it has long grey tassles that open to show yellow pollen during warm spells. It can be hard pruned if necessary and looks good for most of the year especially during winter. Below this I have a Choisya ternata 'Sundance' with bright yellow evergreen leaves. Also, further along is a Chaenomeles with reddish orange flowers in spring. These are underplanted with hardy Fuchsias and lower down is London Pride and Alchemilla and ferns. Take your pick!!

Also worth mentioning that the plant should be planted several feet away from the walls.

in terrace gardens that would be on the neighbours plot!

;^)

Sorry ? I don't understand that last bit :-/
Do you mean it's your neighbours garden and that it's all terraced as opposed to level ?
I thought the proposed site was against a wall ?

Sorry Louise I was just making a joke. Many of the terrac e gardens in my area are very narrow so if you planted something several feet a way from your own wall it would be in the next garden ....nearly! :)

Ah, gotcha !
:-)))

It only needs to be about 18 inches from the wall.

Unless the over hang is 3 feet!

;-)