I've just poured 23m2 of concrete against my house,at one end of the pour is also a trench for a block wall, I'm worried as the slab was not pinned to the house, the level was excuvated down for a step so underpinning I thought would be the answear but this was not done, is this a concern or will it eventually find its compaction rate.thanks

Pinning the slab to your house does not anchor it.. in fact engineers design for movement in slabs and isolation joints between surface beds and walls is a standard practice.. thus the only factor would be to compact the ground underneath the slab, before you pour the concrete, a 98% MOD ASSHTO compaction of a G5 Material will suffice. Remember to use reinforcing on your slab to prevent cracking a Fabric Mesh Reference 193 will work perfectly 50mm below the top of concrete.