The first stage is to assess the property. Understanding the existing roof structure and heights, find a suitable place to locate the staircase on the existing landing and see if the floor will need to be upgraded.
The second stage is for us to take measurements, produce accurate survey drawings, and proposed layouts complying with planning and building regulations.
A structural engineer may be required to calculate and specify, floor joists and steels for the new floor load.
Once all of the above have been produced, send drawings and specifications to the builder for costings. The builder engaged to start the build.