if you check with your local planning portal on line to be certain however the standard at the minute is 3 meter projection from house for terrace or semi detached and 4 meter projection from house for detached, the width is not relivent
As long as the structure is more than 50%glass you should be exempt from planning permission and building regs as this is classified as a conservatory not a extension.It might be advisable to check with your local council,but this is normally the way they do it. graham
It is best that you check with the planning department of your local council as planning rules can vary between different areas. You may also be able to find out what regulations you have to adhere to on your local councils website.
Hope this helps