HELP? door step / threshold

Hi,

I am in need of some guidance and help. I knocked through an old window to become an external door and annoyingly the block work at the bottom just crumbled away down to DPC, that’s not a big issue but what I’m now struggling with is how do I get it back up to the correct level and should I be putting in a precast concrete threshold instead of just standard blocks. There is also a cavity and I’m struggling to see what I would attach the door to.

I did have a builder helping me / giving me guidance but he has now abandoned me. Don’t rely on friends!

Any help would be greatly appreciated.

My thinking is : rebuild the wall and fractured block work (dodgy historic repair that’s failed)
Purchase and bed in a concrete threshold / lintel, fit the door. Build a step further down the line.

If you are replacing the door and frame get one that includes a threshold and just reinstate above the dpc with bricks up to floor level building in a cavity.

Have you measured up for a frame ? Looks to be a little on the small size for what you propose .

Dealing with threshold levels can be a real headache, especially if you're trying to balance weather-sealing against water ingress with making sure the door clears new flooring or carpets. Getting the height transition right is critical so you don't end up with a trap for rainwater or a draft underneath.

If you're replacing or adjusting it, make sure to check the subfloor condition underneath as well—hidden moisture or rot around old door sills is super common and can bite you later if it's not sealed up properly during the fix.