A plan oblique is another of the axonometric family, as you can see three sides of the object and all planes are to scale.

Use the plan to project line up to show the walls.

Often the roof and front walls are taken away to show what is inside.

A plan oblique can then be coloured to show the client.

project lines at 45 degrees from the plan

fill in the walls, and doors

add a ceiling and roof to show the outside of the building

take off the roof and front walls to show what is inside