Their proposals effectively constitute a ban, the screen shot below is from the draft guidance. The figure they provided is misleading, as if scaled, the outrigger would be circa 5m wide, whereas within the Borough all outriggers on Victorian properties are around 3m or less wide.
Complying with the 1m step in from the party wall/external walls would result in a room that is less than 1m wide on the outrigger dormer and nowhere for your stairs to land in the main box dormer. The usual/only possible location for the stairs is to run above the existing stairs, however in this arrangemnt the stairs would run up to the sloping roof.
The proposals also want a 0.5m step down from the ridge line, for the majority of Victorian houses within the Borough this would result in a ceiling height under 2m and not meet building regs.
I have marked up on the screen shot red lines, which represent where new steel beams would be required to support the proposed dormer arrangement. The majority of loft conversions are supported off the existing party and external walls. The requirement of these additional steels will have negative impacts on the environment, the constructibility and the cost of doing a loft extension.
Someone who owns a one bedroom first floor flat, who had purchased it with the dream of one day extending into the loft to create a 3 bedroom flat with a roof terrace, will no longer be able to do so. It will force people out of the Borough, which is not fair given their neighbours will have been granted permission to do their extensions previously.
If you are lucky enough to own a house in Southwark, you will still be able to do a loft extension where the new dormers are supported off the existing party/external walls with no requirement for the 0.5m step down from the ridge line under Permitted Development. Unless you own a house that has already had a kitchen extension, then you would be limited by these proposals as you can only increase your home by 40m3 under PD.
People should be allowed to add space to their home and expand as their family does, I completely appreciate these loft extensions shouldn't dominate the existing building, and this could be achieved with the 1.5m step back from the rear of the property.
