Two plants I can suggest that I have chosen for my garden, are virtually unkillable, will grow in almost ANY soil or weather conditions & require little maintenance are: butterfly/african iris & Celtic Cascade tree. Both can be left to go a little wild for a natural look, or be cared for, to fit perfectly in a more formal garden. In regards to the iris, I removed my entire garden of mature, property damaging trees when I moved into my new house, but didn't want to wait years for a new mature garden, so I searched online for ppl selling/giving fully grown specimens away before they did renovations or re landscaped! The plants were a cinch to dig up, replant in my heavy clay soil & are thriving! I even cut some of them in half before planting and it didn't phase them!

My purpose wasn't to dissuade you from having bifolds if it's something you LOVE the idea of but it's a good idea to think through things like what to do about flies and how will it look given there is a step down to the patio so you're going to have a threshold rather than seamless flow anyway. What is your climate? Which way does the back of the house face? It's useful to know the climate to know what will grow well for you and to know the orientation to understand where you get afternoon sun that you might want protection from in summer and where you get winter sun which you might not want to block? There are other questions to work through. Like people have asked, what's your style? Formal or informal? Native? Low-maintenance? Resort? Seasonal interest? Do you want to keep the maximum amount of lawn and plant only sufficient for privacy and shade or is the amount of lawn flexible? Do you like straight lines or curved garden beds? Do you want to extend the patio? Put in some paths between the patio and the back door and the clothes line and down the side? Make a space for a barbecue? Tuck in a garden shed somewhere? Storage for bikes and sports gear? I don't want to say too much until I know what's important to you. But for starters I'd plant a hedge along the back fence, I'd paint the pergola to make it look lighter and airier, I'd put in some paths and garden beds around the back door and clothesline and hws, and I'd plant a tree but I don't know enough about the block to suggest what sort and where to get the best benefit from it. That's what comes to my mind so far.

Thankyou for all help and suggestions. We are going with brick pillars and hedge between, with chain wire fence for security whilst the hedges grow. We want to tie it in with the front brick pillar and panel fence. We would not the pillars as close t ogeather as the fence, but we arent sure if to do every second, third or fourth pillar spacing?. Appreciate opinions.

if you have an architect or building designer working on your renovation plans they should know what's required in your area but i would prefer to have advice direct from the Council before starting any plans...first locate your original site plans showing the existing house and all the underground water and sewer pipes including the location of the council sewer lines (a copy should be available from Council) and discuss your proposal with local council..we were given permission to build over sewer pipes under strict guidelines but depends on your exact situation...