bricking up doorway question. doorstep related

[Chippee]

Hi all im in need of bricking up a outside door opening and coverting it to a window in a old 1940s house and my question is that the outside door step is level with the internal floor level. The outside ground level is about 5inchs below this and the door step a large sort of concrete lintel. See pic

Do i just brick both inner and outer straight onto this step with dpc or do i need to cut down this step to create a cavity in the floor to prevent water/ damp running to inner side.

Thanks in advance.

 

[noseall]

The step needs to go ideally.

 

[Chippee]

The step needs to go ideally.

Thats what i first thought but when i looked the step is very big and will be difficult to remove. Also if i do remove it do i then need to replace it with 2 lintels as theres nothing underneath except a soul pipe running into the house.

 

[noseall]

Conc lintels will be ok. The devil is in the detail in how you deal with cold bridging and the DPC/DPM.