Foundation/footings advice help

[Diy£££]

I have a single skin concrete block outbuilding and I'm going to be building onto it a single block shed so I've just started to dig the footings and uncovered the outbuilding footings I'm just abit confused how it's been build up to dpc I was expecting to see block work/brick work upto dpc from footings so I could match it on the new build but it looks as though it's just a concrete slab on top of footings all in one with the floor if that makes sense ? Anyone help us out pics attached

 

[Selfbuild2345]

Same as mine, i am doing a garage extension. I dug down past garage founds and have concreted then used foundation blocks to floor level.

 

[Scarlet Pimpernel]

When I did an extension, some years ago, the BCO requested that I continued the trench for the new foundations, ay least 300mm under the existing foundations, to the same depth and width as the new foundations, so you get a half lap joint in the foundations.

 

[jeds]

I wouldn't advise trying to connect the new foundation to the existing in any rigid mechanical way. The connection won't work anyway and will just mean movement in one building influences the other. Far better to build on an independent foundation and connect via an expansion joint that will allow for differential movement.