Floor plans and elevation drawings

Design details: Hi, I need the following drawings for the purposes of a planning application:

1. Existing and proposed floor plans (at a scale of 1:50 or 1:100)
2. Existing and proposed elevations (at a scale of 1:50 or 1:100)

The proposed changes are the addition of a small balcony and external spiral staircase from the kitchen at the rear of the property. Approx drop is 3m, balcony length 2.2m, width 1m.

Attachments:
1. 3D floor plan of the current layout
2. A start I made on existing layout - elevations are fine, however floor plan is of the ground floor flat, so not accurate. (I have the photoshop file I can provide if of any use)
3. Sketch of position of proposed staircase

Please advise if any more detail required.

Ideally I would like original files as well as A3 pdf, as I may have to make small changes to the size of the balcony/stairs before submission.

Thanks
Ideas for the visual style: Simple architectural
Extra notes: