DevilDamo

Permissible development but I’m sure you mean Permitted Development? PD being Planning of which they’re interested in the external footprint while Building Regulations are interested in the internal footprint.

And as it will require BR’s, all elements would need to meet the minimum u-values. On that basis, 50mm to the floor would not be enough to meet 0.22.

That is correct. You could increase the width by another 500mm if need be. Any reason why you are wanting to go down the PD route as opposed to formal PP?

For any window you have and are proposing to be used for escape purposes, just make sure it complies with the escape requirements, i.e. max 1.1m above floor level, min. opening area of 0.33sq.m with a min. dimensions of 450 x 450mm, etc...

Agreed and is just one of the ‘clever’ ways PD can catch people out. The thing that comes up most is having a side extension and a rear extension under PD but linking them requires formal Planning. If in the OP’s case we are only talking about a single storey rear/infill extension, there’s a 99% chance it’s sail through the formal Planning process anyway. But with that is a formal application, increased fees and a determination process.

I saw from another thread your attached on the left but what’s to the rear... attached to another property? With having windows to the front and right will obviously restrict your design and layout options. Assuming those two elevations are the ones that can only accommodate windows, then you will have to try and keep all the rooms that don’t require natural light/ventilation or escape requirements to the left and rear. Those rooms or areas would include a Kitchen, Utility, W.C., Stair, Bathroom, En-suite and Dressing areas. To get the layouts right would require a bit of work and the thing I’d first consider is to have the entrance on the southern wall leading to a Hall with the stair and a Kitchen/Utility/W.C. on the left and the rest of your entertaining space on the right. This would also depend on the existing drainage points and access.

That would mean the infill/squaring off extension would be determined under both the rear and side PD rules and restrictions. It comes up so much and many are refused CoL applications because of the understanding it is only a rear extension.

I’ve tried that before but the PO argued that I am now extending beyond a wall that is not original and has been built as a result of the partial demolition.

Yes but am not sure how that relates to the OP’s situation!?! Unless I’ve missed something somewhere in that the smaller rear projecting part (3.5 x 3.1m) is not original and is an existing extension? If that is the case, then Part A would be considered to be PD.

I’m not sure what you mean? Rear infill extensions have to be checked against the PD rules for rear ‘and’ side extensions. It’s explained here... https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/830643/190910_Tech_Guide_for_publishing.pdf (Page 23)

Your original Planning approval has the reference number 16/508020/FUL. The reference number referred to in the Informative is 16/503457/FUL. Your NMA reference number is 19/503457/FUL. Where has the Informative reference number come from? Was the NMA application submitted after the works had been completed/signed off? Am I right in saying the changes you were seeking as part of the NMA application was stepping in a part of the ground floor side wall along with raising the cill of the first floor side window (enabling the lean-to roof element to continue below)?

You’re right, it does. However, if the ‘existing’ house is ‘original’ then the rear infill would be checked against the PD rules for rear and side extensions. And again under PD, that rear elevation has two rear walls. Under formal PP, it would just be deemed as a rear extension.

Dressing room/wardrobe, Bedroom and Upstairs Landing maybe? Btw, Building Control would not allow you to utilise an escape window in which you’d have to access via a dressing room and en-suite. You’re also not allowed to have a door between Bedrooms and Dressing rooms as a DR is considered to be habitable and without a window, it’s escape would be through an ‘access’ room as the DR would be an ‘inner’ room. If the Bedroom cannot be provided with an escape window, your other option is to provide a protected staircase. Just out of interest, how will the Bedroom meet the ventilation requirements as per AD F?

PD relates to the ‘original’ house, which is not necessarily the ‘existing’. So assuming the part you label existing is infact original, then Part A is not PD as it’s greater than half the width of the house. Part B is PD and can be the full length/depth of the original house.

Your two options would be Variation of Condition or Non-material amendment application of which the latter is cheaper and a quicker determination process.

I thought I was going mad as I was pretty sure I had already replied to this but then saw the duplicated thread in a different section.

If a SI is not carried out prior to the purchase or prior to the submission of a Planning application, the LPA will definitely request one be carried out and submitted to validate and/or formally determine the application.

Yes, no openings below 1.7m so you are normally allowed high level/fan light windows. The only time the permanently fixed shut requirement comes into play is BR’s and those windows, which are located within 1m of a boundary. Unless the trees have some kind of protection in the form of TPO’s, then applicants cannot look to use them as a balance to help provide or maintain privacy issues.

Just remember to qualify for exemption normally means obtaining a self-build mortgage and the property cannot be sold within three years post completion. If you were thinking of selling, some of those design costs could be absorbed throughout the build and then re-sale costs meaning their impact would not be ‘as bad’.

So to clarify what’s happened... instead of the new foundation running parallel with the boundary, it runs parallel with the existing house side wall resulting in you now having some dead space? If so, I assume the rear left corner has been taken as the setting out point which then runs down in a straight line? BCO’s are there to check the works, not design them so am not sure why the BCO would have insisted on the design being changed. Does this new design now not comply with what’s received Planning approval, albeit Permitted Development or a formal Planning application?

Would any SPA/SANG or CIL contributions also apply to the new build dwelling, which will also start to increase those pre-construction costs? Even though the fees may seem a lot, what percentage of the new build cost and/or re-sale cost would they be, probably quite minimal?

Some LPA’s insist on fully obscured glazed windows irrespective of their height while others state the part up to 1.7m is to be obscured while the part above 1.7m can be clear glazed. That would be a conversation you’d need with your LPA but as mentioned above, you shouldn’t even have to get to that stage of compromise.

In ‘normal’ Planning situations, first floor side facing windows would need to be obscured glazed and contain no openings below 1.7m above finished floor level. This is also the PD requirement and guidance. However, each application is determined on its own merits so the LPA should be a lot more relaxed in your case as the new first floor side window would not appear to pose any overlooking issues. Just make sure you deal with it via a formal Planning application (and I assume part of the main extension works) as LDC application for PD would automatically restrict its design and appearance. Not to mention a PD window would not meet the BR escape window requirements resulting in you having to provide a protected staircase.

But again, what are you comparing this to? How do you know how much time it’ll take to produce these ‘few drawing sheets and spec”? Bear in mind the design and detail is taken on by somebody who is qualified and proficient at doing so and will therefore take on the design risks associated with the works should any issues arise during or post completion. In order to obtain accurate build costs, you’ll need to provide contractors with full plans drawings including engineers’ details and calculations. Although a BN application wouldn’t normally need to include as much detail, contractors may not be comparing apples with applies and therefore deviating from what could be BR complaint. You can’t have the best of both worlds.

The protected corridor would have to lead to a final exit and not through other rooms. Just a note that FD20’s would normally need to be fitted with intumescent seals. As these doors and seals need to be a tight fit and remain so throughout their life span, the doors may over time loosen up. This is why the majority end up fitting FD30’s as they don’t require the seals. Edit: The specification is called up and noted in the bottom left of your first drawing.