I intend to replace all the windows in my house with upvc units. I have done regular window replacement before but in this case i have 2 bay windows that need replacing. Does anyone know if there is any particular rules i need to follow? someone told me that the frames have extra supports in to take the additional weight of the structure above it. Any tips would be much appreciated. ![Confused :confused: :confused:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)