Dave Jones

leave it to the builder.

yep its a fail, no ponding is allowed. https://nhbc-standards.co.uk/7-roofs/7-1-flat-roofs-and-balconies/ Why would you put up with it anyway, its a crap job. Get them out.

unlikely the slab runs under the house so nothing really to worry about. Once you crack it in the middle the whole thing will move.

150m2 for 200k VERY optimistic more like 100m2 and thats still tight.

not to mention services connection. leccy meter is 3 months and counting.

no. K2 states max height of 800mm. which contravenes part O and part B.

interesting obscure and expensive build choice with very very few contractors certified im guessing. Why?

you need the cash in the bank. anything else will cost you. If you think it will be done in 3 months your in fantasy land. Lead time of lintels in 4 weeks for us. 12 months and you will be very lucky.

it doesnt look to bad really, they are on top of the trays. Good to keep an eye out but looks tidy job. Much worse can be found on here. Do you have building control monitoring ?

it may be the odd sizes weren't in stock. As its an outbuilding rules could be more lax. As long as the trays above the lintels are sorted i don't think id be over worried. Post some pictures.

can understand it, they are using a waste product. Until this country comes up with a scalable plan to insulate and convert to heat pumps i cant see these schemes not being a worst best option.

m2 expect £3k+

i cant see any genuine contractor offering a fixed price at anything other than extortionate rates to protect themselves. You have to be realistic, prices of materials fluctuate. Get the plans QS'd add 20% contingency and go from there.

Lintels upto 1.2m only need 100mm bearing, over that its 150. https://nhbc-standards.co.uk/6-superstructure-excluding-roofs/6-1-external-masonry-walls/6-1-12-lintels/ It's a warranty fail for NHBC so i would have them removed and correct sizes. Also I'd want the door to be a HD lintel (taller). Also make sure the builder puts a tray and weep vents on every lintle.

get the plans properly QS'd https://www.estimators.com/ will give you the build cost down to last nail and also let a builder do a quote much faster as he has m2 for everything. Architects will put it out to tender but will pull your pants down for the service. May be worth dropping into to your local travis/jewsons and asking for some names.

for demo, contact your local muck away firms who supply stone etc. They allways after rubble for to recycle and sell on and often will drop and remove the building for free/cost as they keep the rubble. If you strip the internals first of all timber, fittings, etc they would drop and remove it in a day easily.

you can get all the section details from here https://www.buildingregs4plans.co.uk/pre/new_build_plans_new.php

BCO is ok in fairness, its the warranty inspector who is anal about every little thing. Probably end up with guarding and remove it after the final visit.

Part L reg 50 The measured air permeability to be not worse than 5 m³/(h·m²) at 50 Pa.

Sure this is going to catch a few unawares. new Part O (overheating) states: Any guarding to be sized to prevent the passage of a 100mm sphere, to be 1.1m high from floor level, to be not easily climbable and to be capable of resisting at least the horizontal force given in BS 6180:2011. Park K states: "section 3.1 At Opening windows except roof windows in loft extensions, see approved document B1" max height 800mm Park B states "section 2.10 bottom of opening area is a maximum of 1100mm above floor". NHBC also muddies the water, they say you can ignore Part O guarding heights if you do not rely on windows for heatloss (MVHR). also they introduce a tolerance for guarding of 100mm lower. https://www.nhbc.co.uk/binaries/content/assets/nhbc/tech-zone/nhbc-standards/tech-guidance/6.7/tg-6.7-20-guardingconsiderations.pdf So there seems to be no way to get around guarding and passing regs. Height from Floor Part O Part K Part B 800mm FAIL PASS PASS 900mm FAIL FAIL PASS 1000-1100mm PASS FAIL PASS 1200mm PASS FAIL FAIL

quite right, taking the existing roof off takes all the ceilings with it. not liveable.

you could allways knock a hole in your extension to unblock your downpipe. you would need to access next door anyway which is rude.

no, you need a chippy to pull the timber off. make a tray from a roll of dpc. https://www.travisperkins.co.uk/damp-proof-course-dpc/ndc-polipak-dpc-600mm-x-30m/p/994980

dpm looks very low compared to the floors, not dug out yet ?

dont give them the satisfaction. PC have zero power when it comes to planning. Just ignore the moron and dont respond to them. It only gives them ammunition. Next time you see him in passing just laugh at him and carry on walking.