Duncan Heather, founder and principal of the Oxford College of Garden Design and one of Europe's leading garden designers is a man of few words, until you ask him: "Does Good Design Matter?"

"If you think not," he says, "then take a closer look around your own neighbourhood. You won't have to look very far or very hard to see lots of examples of bad design which could so easily have been avoided."

The very first Golden Rule of Good Design, according to Duncan Heather's design philosophy, is that the building itself (usually the house) must be integrated into the landscape. What this means, in lay terms, is that if, for example, you have a traditional stone building, you are probably not going to win design awards for surrounding it with chunky contemporary glass walls and steel overheads (pergolas, arbours and the like).

Scale is also crucial and is again, dictated by both the existing buildings and the size of the plot.

You can easily see how crucial scale is by looking over the garden fence at your neighbours' plots or other people's front gardens as you drive around town. Notice how many houses will have a grand entrance and then a silly, mini-size terracotta pot with a tiddly, twisted topiary tree flagging the doorway. The wrongness of the scale will just jump out at you.

Another common bad design is the curvy, serpentine path running down the middle of a medium-sized rectangular town or village garden which breaks another fundamental "good" design rule and, worse, splits the long rectangular plot in two which, instead of enhancing your outdoor space, will end up making both sides almost unusable.

Duncan will often talk about interior design to make a point about good and bad garden design. "If you have this type of medium-sized, long, rectangular garden then think about what kind of lawn you want," he says.

"Lots of people again choose a curvy, almost amoebic shape and my response to that is that if you think about the garden the way you think about the inside of the house, you would never put a squiggly-shaped carpet in a rectangular room."

Or would you?

What do you think constitutes good/bad design and are there times when good design demands that you break the rules?