Should this be filled?

[padstar]

I am about to have my rear doors installed. The threshold sits 1 course above dpc.

The photo below shows the cavity below the threshold. Should I fill this with 100mm jablite or similar before putting the doors in? Or leave as a empty cavity for 1ft below doors

 

[noseall]

I am about to have my rear doors installed. The threshold sits 1 course above dpc.

How does this affect floor level - i.e. does it all work? A course below DPC seems low...

Should I fill this with 100mm jablite or similar before putting the doors in? Or leave as a empty cavity for 1ft below doors

Usually the inner course/s of bricks between door jambs are removed to allow the flooring material (concrete, screed etc) to pass the masonry threshold and finish butted against the door sill. No one can see from your photograph as to how your oversite has been constructed.

 

[padstar]

The dpc is about 600mm above outside floor level and oversite. It's a suspended timber floor coming in to the inner skin of blockwork