Minimum window dimensions

[moles]

Am starting to think about what windows to order for the front of our house, the openings are not very large 1100mm wide x 1070mm high. Can anyone tell me what the minimum size openings I have to comply with regarding upstairs rooms. All I can find online is a dimension of "no smaller than 450x450mm". And if below 800mm from floor needs to be toughened glass. Windows will be PVC I don't like plain all openable windows would like to split the dimension into 3 with a full half opening and the remaining half with a small opening top part but think this will be under the 450x450 rule. The windows at the minute do not comply with this rule but are 30 years old and hardwood but are falling apart. (Going PVC as I can't be arsed with the maintenance of wooden windows)

[moles]

darronwall said:

rules only for newbuild

Is this deffo the case?.

Bigdom were yours like french doors then with a mullion fixed to one of the doors?. Could be an option.

Edited by moles on Saturday 30th May 07:33

[moles]

Cheers everyone I would like escape windows if possible, Bigdom yes photos would be good if you can.

Edited by moles on Saturday 30th May 20:35