Taking your first point it is always advisable to go for a gravity fed drainage system for two reasons:
* Noise
* Maintenance
We would only resort to a Sani-flo system if it is not possible to reach a drain connection. Although we have not seen your layout proposals we consider through careful spatial planning that it should be possible to reach a drain point, Roding access will always be needed even if you go for Sani-flo option.
On your second point putting in a Juliet balcony will meet objection from the planners as they often introduce infringement of amenity. The only time that we have not had a problem is when they are used in new build or there in no possibility of overlooking adjacent property.
In terms of light we consider this to be a very important aspect of design, however there are a number of points that you must consider.
* If you have glazing below 800mm it must be safety glass
* Openable windows must comply with part B of the Building Regulations. The window that you are suggesting may not satisfy Building Regs if this window tilts from the base.
* Have you had your plans checked for compliance with Building Regulations in terms of escape, as you may require adaptation to the main house in order to achieve compliance?
We trust we have answered your question; however, should you require any further information, please do not hesitate to contact me
