Active job

Waterproof one side of the garage to be converted into a permitted flat

I want to convert a garage built on top of a concrete slab with concrete blocks of about 1m height to a detached dwelling to be used for residential living purpose. The garage was built in 1974, and there is no damp proof membrane underneath it, nor along the joints between the concrete slab and concrete blocks. The concrete slab is elevated on three sides of the garage, but on one side it is level with the ground and either due to inability to dig into the volcanic rocks or laziness it wasn't boxed in from that side either. I've removed the soil from that side, so you can see on the photos how the slab is mixed with the rocks. The garage will be re-clad over the blocks, but to avoid damp rising and entering the joint beween the slab and blocks, there may be a need to do some waterproofing. I'd probably do it on all four sides, but this job is for the difficult side where edges of the slab are not easily accessible from the rocks and non-boxing the concrete on that side. Digging deeper to what I've done (about 10-15cm) is not an option, as the rock is too big to be broken down and there is no access for big digger, plus it may damage the slab. So, what I need is someone who has experience with this kind of job, and especially with Auckland council requirements as I need a solution that can be signed off by council and permitted. Please ignore the rainwater pipe, it will be removed prior to doing the job and won't be going back there.