Single skin wall unstable

I had some windows and doors fitted in my porch a couple of years ago.

The door catches slightly on the strike plate, so you have to close the door with a bit of force. This seems to have caused the single skin brick wall at the side of the door to crack, and it moves a significant amount when the door is closed with any force.

I’m going to modify the strike plate to hopefully allow the door to close more easily, but it’s unavoidably going to slam from time to time. I’m concerned that the movement from this will at best crack any plastering I do, or at worst the wall will be in danger of collapsing.


I had a few ideas to fix it:

1. Take wall down, rebuild it as a 9 inch solid wall with engineering bricks and a garden wall bond, use SBR enhanced mortar and tie it properly into the main house wall. Fix window and door back into it.

2. Take wall down, remove the window above the wall and place a full height PVC window there.

3. Take wall down, replace where wall was with PVC window with solid panel instead of glazing, leaving existing window above.

I was wondering how other would tackle it. I was leaning toward rebuilding the wall stronger.

Any thoughts welcome
Cheers

This bit of wall will always be weak, as there isn't enough masonry above it to add any weight to it, also it's only been butted up to the house wall, and when the door flexes/slams over time it will work the brickwork loose.

You could have a go removing the window and rebuilding this wall as you described, would be stronger if it was 'toothed' into the house wall, but this is more work. Perhaps a doubled-up wall starter might work you could then tie the brickwork together with English bond.
Not sure you'd need SBR.
I probably wouldn't use DPC either (again will add to weakness), as you mentioned a couple of courses of engineering.

Good luck.