We use lavender all the time for edging driveways and must have planted out a few 100 already this year - we love it and your quite right it is great for this purpose. The plants spread a good 60 - 80cm making them a lot wider than the beds in this front garden - still could work though if they are prepared to lose a fair bit of drive. As for the evergreen issue the RHS, bless em, do a great job and 'technically' - as they are bound to quote, lavender is evergreen/grey, but do present a sparse winter foliage which can look terrible if there are severe frosts - if you don't want to cut them back that is. After a couple of seasons hard pruning is recommended to stop the plants from getting woody/leggy and whilst there is debate whether before or after winter is the best time to prune, its up to the garden owner if they want to look at bare woody growth at the base/centre of the plant for the sake of a sparse spread of grey leaves through the winter. This doesn't matter so much if the lavender is part of a bigger planting composition, but on its own up against a fence our opinion is that its flowering qualities and limited foliar attributes would not warrant inclusion when other reliable evergreens such as Pittosporums 'Tom Thumb' or 'County Park' would fulfil the low evergreen role much better, leaving flowering effect to non rampant climbers such as Trachelospermum jasminoides, Rosa 'Zephrine Drouhin', and Campsis radicans with shrubs that can be trained onto fences such as Itea ilicifolia and Garrya elliptica, to quote just a few.

Morning Jacky, I am a keen gardener with an RHS course behind me and I was taught that looking for trees with 3 seasons of interest for a garden is always a good idea ie blossom in spring, pretty foliage in summer and autumn fruit. Something like Amelanchier lamarckii which gets to 10m high and 12m wide has pretty dainty blossom in spring delicate bronze foliage in summer and red orange leaves in autumn. The birds also love the purple black fruits which follow. Or a Malus 'John Downie' or Malus Floribunda both vigorous crab apple trees with a long season of interest. I would probably not go for the Tuscan pillar conifers because they will act as pointers drawing your eye to the houses you are trying to screen. Birch (Betula Utilis var Jacquemontii are beautiful however they will reach 15m or possibly consider weeping birch Betula Pendula "Youngii' which makes a dome shape and gets to 8m high and 10m wide. Perhaps have a look at the RHS website which is very helpful.

Our terraced garden we moved in last year. Stone Chipping's and the odd plant and very steep steps . I'm a huge fan of garden rooms and my favourite era is arts and crafts gardens Gertrude Jekylls designs influence mine :)

I'd steer clear of painting the walls, and in any case not without discussing first with your neighbour (assume that is the neighbour's property?). If the neighbour did allow, it would be very easy to span a pergola-style structure between both buildings, and from this you could have a retractable sunshade (see below link). This could provide a much more intimate space for evening dining/relaxing, especially in early & late summer when its a bit cooler. You wouldn't need to purchase or build an independent pergola, just the shade kit, which you could suspend from a decent timber frame between both buildings (of course Party Wall Act comes into play and you would need the appropriate written permissions from your neighbour). http://www.tuin.co.uk/Sliding-Garden-Shade-Awning.html?productid=17374&cat=334&utm_campaign=googleproductsearch&utm_medium=googleproductsearch&utm_source=googleproductsearch&utm_term=Sliding+Garden+Shade+Awning+3m+x+5m&_fpts=1462771551?gclid=CKK22Kap0swCFdZAGwodi6MBuw