I am building a low energy detached house in South Wales which is to have timber balconies fitted to the 3 floors and supported from the ground.

The main structure is built but as the structural engineer I used for the general structure is not experienced in heavy timber techniques. I would like someone else to look over the design.

My way of calculating timber spans is ... span in feet divided by two pluss an inch = joist depth --- trimmers, double thickness of joists, beams etc three times.

these are rules of thumb and not so good for beams but k for normal joists etc.