Hi, It depends on whether the works fall under Permitted Development (PD). If they do then you can in theory have a max height of 4m to a parapet and 3m to the eaves (flat roof level essentially). See page 17 and then page 12 on the linked doc below). These dimensions are from the natural ground level, not the finished floor level. Note, there maybe be Rights to Light issues with a 3/4m high wall on the boundary that sits outside of planning. However, if you have submitted a Householder planning application the PD rules do not apply and the LPA can stipulate what they feel is appropriate in terms of impact on neighbours and other issues such as design. This is perhaps where the 2.5m height restriction has come from. It is not terribly unusual. You should be able to get 2m internal headroom. We often back the full-height kitchen cabinets up against these walls to hide the lower appearance along this edge. Then by the time the roof slope travels over the 600mm kitchen unit depth the height of the ceiling is around 2260mm which does not look too low.https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/830643/190910_Tech_Guide_for_publishing.pdf Please let me know if I can be of further help, Carl

All planning comes with risk, especially when there is no precedent for it. Also, there is always potential to get planning permission (even when it seems less than likely), but it is never guaranteed. You could call the planning department and ask for some advice from them - though that can be very difficult to get these days. You could submit a pre-app enquiry, though the time it takes to do that may mean the flat you're interested in has sold before you get the information you want... In summary. Yes it is a risk. Only you can decide if taking that risk is worth doing and if you can't make the extension is the flat still be worth the investment, or will it still be a place you could live happily... There may be alternative ways to improve the flat that don't involve an extension. If you'd like a thorough sketch redesign to use for a pre-app enquiry and to explore alternative solutions to the extension, then I can help you with my Big Picture Plan. My next available date for this is 18th April. You can find out more and book that here: https://www.i-architect.co.uk/bpp.html Jane award winning chartered architect eco-home and conservation area specialist www.i-architect.co.uk

It was the last owner who went for the style of high narrow small window. I inherited the building without the window fitted. It was approved to be clear glass, but high up. It overlooks a small unused barn, but is road side. I want to let in a lot more light hence three narrow pilar panes of glass - frosted because I don’t want anyone looking in from the roadside and because i have good views from the other side of the house, so don’t need more view if that makes sense, just need light and privacy. But to answer previous question the frosted/smoked windows will overlook someone’s land, but not someone’s house or garden, or driveway.

Because you are looking to do a loft as well as build out this gets quite big and may be beyond permitted development. Given that even with permitted development the local authority can consult neighbours and right to light may come into play I think that you should be getting professional advice. In my experience the local authority planning department varies from one area to the next, so you may be lucky and get good advice, most likely they will be vague and useless. I think you should set up a consultation with a local architect for an opinion on local policy and a guide to cost of nearly doubling the size of this house. Separately I agree with other comments that you should keep the side access or accept complications with the neighbours and the window cleaners ladder going through your kitchen once a month.