Here's one we did!We put in a window at the bottom of the stairs and a door at the top! It could be difficult to get a landing in once your'e into the loft, depends on where the stairs have to come up, due to head height etc. However, I do believe that Building Regs require a door and a turn into the loft, so that you can't fall down the stairs if the door's open. Before you go down the route of what you'd like, find out what you can have, that's always my advice. Get in touch with your local Building Control at the Council and they will tell you what you've got to have in order to get it signed off.

Hi and many thanks for your reply it is really helpful. We have gone out to another 6 firms for price and seems to be about right, though first person on site has stated may not need underpinning of whole area? Our builder knew him and worked with him before but does not do the work himself, but has suggested the reduction of his groundwork will reduce cost of extra foundation. Yes has been designed by structural engineer who feels 9 points of need due to steel going in for new extension replacing large expanse of existing external walls on right angle. hope that makes sense and thanks again.

Hi Heidi, Having just done such a project (and learnt a little from it...): Ceiling heights: minimum thickness of a floor is around 200mm/8" but some of that can be "reclaimed" below e.g. by leaving the joists exposed. Above is trickier because insulation requirements for the roof mean you can't really do that much there; the distance between the outer surface of the roof ridge and the inner ceiling will end up at least 250mm. Do your figures. Regarding the steelwork, there are lots of technical options to build this and "all of them may be right" as in (not) needing a ridge steel beam. Have you got an SE (structural engineer) spec for it? You can talk directly to steelworks fabricators about this. Builders tend to buy RSJs from specialist companies whose business it is to "sell steel made to size / spec" - steelworks fabricators. Some builders like to "cut&weld on site" because it saves them time but workshop welding and steel preparation tends to have more consistent quality and is preferred by structural engineers and/or insurance & building control (the latter often because of the fire risk for welding work on small sites). So this may be a case for more questions to the builder ("who's your steel fabricator and would you mind me talking to them?"), or a 2nd opinion by showing the plans to a fabricator and asking them for how they think this could/should best be built. The technical term is to request a "method statement" - how will the steelwork be made to conform to design, comply with structural spec & building regs and/or constraints of property deeds, and how will it be installed (to satisfy site insurance and Health& Safety regs, and/or other provisions e.g. from party wall awards/consents) ?" On the fire suppression system: building regs part B (fire safety, https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/485420/BR_PDF_AD_B1_2013.pdf ) extensively talk about "means of escape" which usually are protected / made "safe" by the additional fire resistance hallway walls and fire-rated doors to the hallway/stairwell provide. Where you have open-plan, the guidance says (quote): "Alternatively, it may be possible to provide sprinkler protection to the open-plan area, [ ... long sequence of auxiliary requirements/explanations ... ]" And the devil is in the detail. Not the least because "sprinkler" isn't the same as "mist sprinkler" (let's not go there now, rabbit hole...). It's definitely worth pre-clearing the design / fire suppression method with building control, because once you start, having to "alter" later to put extra partitions in not only blows costs out but also kills the design. From my own experience - do not let the builder "just start" because ... they may hold _you_ to ransom if their (hidden) cost-saving provisions are felled by external agents/influences. With no roof on the building and neighbours breathing down your neck for potential damage or perceived risk, or building control refusing signoff unless major changes, you're in a pretty bad negotiation position. Building regs will pre-clear designs for you, possibly for a small fee. Good luck !

Hi AMB, I see your dilemma. I don't have first experience of your situation so I'm not sure if my comments will be of any help but I'm going to be starting a loft conversion too next month and I'm in an edwardian terrace ( one neighbour already has a loft done ). From my experience, it is best to casually speak to your neighbour about your future intentions because when the time comes you will have to ask them to sign a Party Wall Agreement anyway. Just a few questions - Is the dormer side/cheek built right up to the boundary/party wall? If yes and you want to maximise the size of your dormer, do you plan to join your dormer with your neighbour's dormer if they agree to block out window? If neighbour does not allow you to join onto their dormer, you will have to build the dormer 500mm in from Party Wall because the builder needs space to tile the dormer side ( so your loft will not be so wide ). This is the dilemma we had but luckily our neighbours agreed to join onto theirs. You may wish to speak to a builder about this 500mm gap but that it what our architect and builder told us. I'm not an expert on the 'right to light' but if you neighbour already has another window and if you decide to build within your boundary I don't see why it should stop you, I assume you are doing it through the Permitted Development route? Do you also have a chimney stack at the back? Have you met your neighbours? It's a bit of a tricky situation because you haven't bought the property yet and you don't know what they are like. I don't think it matters their window overlooks your roof as they will just get a view your tiles and you can't see into their window, they should have thought about that before they built their dormer. Did they build it a long time ago?