As the foundation to the existing garage is not likely to be traditional it s probably a shallow slab a new foundation may be needed for the new wall.
Garage door infill foundation.
The new house next door has a shallow foundation and because it is such a tight footprint substantial shoring was needed to stabilize both this house and the neighbors.
The ends of the lintels should be cut into the existing brickwork to ensure a minimum end bearing of 150mm c if the existing floor slab was thickened at the door opening and a lightweight form of construction is proposed for the infill it may be possible to carry this infill on the existing floor.
Pouring the foundations and blocking.
As part of the garage conversion it is likely that the original garage door will be in filled with a new wall and possibly a window or door.
A new inner skin on the external wall or filling in the garage door with brick block and a window will all add extra weight.
As the foundation to the existing garage is not likely to be traditional it s probably a shallow slab a new foundation may be needed for the new wall.
The retaining wall on the uphill side of the foundation is ten feet high and the building will be four stories tall the maximum allowed for this infill site.
In fill garage door as part of the garage conversion it is likely that the original garage door will be infilled with a new wall and possibly a window or door.
Check the condition and suitability of the existing foundation or floor when the door infill area is excavated.