Timber retaining walls need replacing

The house was built in the 80s and the timber retaining walls around the property have started to rot and may eventually need replacing. They are around a meter high and about a meter from the boundary fence. Has anybody done any renos that involved retaining walls? How much did it cost (materials and labor) to replace? Would timber still be the recommended material or should we just use those extra large bricks?

I'm doing a concrete sleeper & steel post wall at the moment. Largely because going this was I can have the look of a masonry block wall for a cheaper price (the work involved is largely the same).

I stayed away from wood because it will rot (even treated hardwood). If I had to use wood for some reason I'd use steel posts so that at least you could slide the sleepers in/out as required if you had to.

checkout www.concretesleeperscanberrs.com.au for some ideas.

I've done both blocks (2,000 at 25kg ea), and lately re-Inforced concrete sleepers.
For speed and simplicity concrete sleepers win hands down, and a browse of the http://www.concretesleeperscanberra.com.au pages shows how many styles you can get.

Sorry I can't price up as it involved other works at the same time.

Ensure you install the right fill and drainage behind the wall.

Thanks Matt and tezzab for your inputs. Gave me a better idea of how this can be done. Just need to find local suppliers in Perth and waiting for further responses to this thread regarding estimated costs.

Depends if you want to DIY or pro installation. Check your Council, but for many, under 1m won't require Engineering.
Looks like you have choices in Perth . Some use vertical posts, others steel C or H beams. All seem to have DIY Installation info.
The sleepers are very heavy, depending on size, so it's best to use a machine for placing them.

http://www.wonderwalls.net.au

http://www.conwood.com.au

http://ezyretaining.com.au

maybe more around, that's just a quick google search perth concrete sleepers