Gus Potter

Write to the planners and ask them.. Did they do a "report of handling" that identifies the material considerations when granting the current permission? Lucky for you you have made a material start! First though why does your Architect think it needs a fresh application rather than an amendment?

That is good design. You use every tool in your designers box to suit the build and play to the Clients strengths. Often the "old schoool" methods work very well.

Hiya. I'll start with a general over view for folk on BH. Simplistically the warm roof works by keeping the structural members on the warm side of the insulation thus they are protected from condensation. On top of the structural joists we put a layer of say OSB and on top a good vapour barrier (Alutrix 600 is one) and that stops moist air from getting into the insulation layer, condensing and causing problems. This has many benefits in that we can run services and put in down lighters etc all on the warm side without having to seal stuff up against moisture. We can construct the walls by stopping moisisture from getting in and condensing in the wrong place.. we call this the dew point. Where the dew point is most likely to occur we can ventilate or similar. Say in a standard TF wall. @Sunil237 too right there is a cold bridge but also we need to control the vapour transfer at the transition between the wall and the warm roof. While it is technically posssible to mitigate by theoretical detailing ( drawing stuff) it is not buildable in real life unless you want to pay thousands extra.. no builder I know is interested and you probably can't afford it. Your Architect will duck this big time unless they are able to take a pragmatic view, recognise that there is no ideal solution and design something that is a good compromise and buildable at reasonable cost. I've shared the detail below for solid roof joists.. part of my IP property (yes it is mine as this is from basic maths design principles and also includes the rest of the structural behavoir) but what I can say is that every job is different. For pozi joists you could use a good air tight foam around the webs and flanges. Folks don't pinch it or you'll get into trouble but by all means use it to give you ideas. The detail below is based on pragmatic design, experience and knowledge of how each room in the house is going to be used and the structural design. The below will sort out the worst of the cold bridges but not all, it is buildable at reasonable cost. Hope this helps a bit and gives you ideas. The main thing is not to get too hung up on mitigating every cold bridge.. just do what you can and beef up the insulation levels where it is easy and cost effective to do so. The above should stop any really nasty cold bits which would result in say a line of mould on the wall or movement in the finishes due to significant moisture variations which can cause unsightly cracks in the internal painted walls and so on.

Top comment. One of the builders that I work with came round today and we were talking about not getting our own house finished. His wife has said to him.. if you don't pull your finger out then I'll do it. He said.. my wife is a better trades person than I and bloody handy on the tools! I need to finish it to avoid embaressment! (excuse the spelling) That's a good photo Nod showing the shrinkage crack adjacent to the stair and what a decoupling matt actually looks like.. it lets Buildhubbers see what can be expected without drama. Bit of tecky stuff for all. Very roughly screeds and concrete slabs that are cement based (even with additives) go through a journey after they are placed. In the first 24 to 48 hours they undergo what is called plastic shrinkage and this tails off after a bit. But this induces residual stress that does not go away. All the chemicals are interacting and bonding and this causes movement that we call this plastic shirinkage. Next you have drying shrinkage and this is the thing we are interested most in when doing UF and say tiling on top say. If it was my own house I would want to heat the slab up to the working temperature in the winter. While at the moment you may not see any cracks the slab could be in tension and a bit of extra heat will cause a sudden opening of a crack.. probably one you can't see from the plastic shrinkage. In my own mind if you just put a matt over the cracks you will just shift the movement elsewhere. Also the matt is quite thick so you'll need to make up the levels which could cost a fair bit on adhesive etc? Can you not just fit the kitchen and install the floor finishes later or do you you have free standing and mobile units? I never used to use a matt until I tried my luck on a suspended timber frame floor with UF between the joists and got stung! Big crack right up the middle of the public bathroom tiled floor.. that lined up with the bog pan.. it was the first thing you saw when you sat down for a "rest". At least it was my own self build.. but if that had been for a Client! In the past we used smaller tiles and they were a bit more forgiving. I have these large format ones in parts of my house. They are expensive and not easily replaced thus followed @nod advice. Yes a tiling matt is a heat barrier.. but as I have said before a lot of this stuff is about compromise.. we like rugs on the floor which insulate the UF.. pragmatism needs to prevail.

That is a good appoach keep things low key and friendly if you can. I'll make no further comment as no expert on PWA if you are in England. If in Scotland then I know a bit more. Will be interestng to see what other folk think.

What type of cladding are you fixing.. can you do us a wee sketch of what you are thinking about doing?

So would I after say 3 months once the insulation has compressed / suffered from creep.. then you lose the friction that intialally makes it seem solid. Also if using timber battens the timber shrinks and that too further reduces the friction resistance. After that you are relying on the bending capacity of the fixing alone..

Although folk on BH may disagree, SE's and Architect's often work on quite a tight business model, especially if they employ folk. I offer from time to time offer a service where folk pay me for an intial SE consultation. But as I used to be a building contractor in my last life this turns in to a general over view. This starts off with a phone call and a general chat, I ask a few questions but mostly try to listen, then I identify what initial info we need to make some basic decisions. I try and explain why we need to do things and answer any questions you have.. the objective is to inform you as much as I can and give you the tools to make your own decisions. Part of this process allows me gauge how knowledgeable your are and where you may need help. You can cover a huge scope in a couple of hours on the phone. My approach is to say up front.. here is my hourly rate for; general advice, a supportive chat and advice on the process of selecting other advisors / designers and how you put together a document that specifies what you think you need and importantly where you think you may need help. At the end of the day I always make sure that folk feel they have got value for money, usually this results in over all savings and that justifies my fee. What I do is different but it does work for some Clients and me. Try if you can to find an experierienced SE who will spend a couple of hours chewing the fat with you.

Not quite sure how you want to set this up but have a look here: https://www.ejot.co.uk/Building-Fasteners/Products/ETICS-Anchors-/c/ETICS_ANCHORS

Mention to them and ask for their views.

I appologise.. I should have used different language. The proximity to the boundary is one big key. Please check that this has no structural implication as the roof may have been designed as a diaphragm thus making a hole in it for a Velux may not be the best thing. But later you could if you fail to comply with the rest of the regs. I rest my case.

Yes.. but they have lost their shirt and by the time they called me in it was a bit too late. This is much more complex than you realise. The design loads are often increased, the steels coroded.. then you add openings.. large area of glass for example that are sensitive to movement. Often we want an old building to move as freely as possible. Archaeology, flood risk can cause major design challenges that can massivly impact on your budget. For me I love this stuff as it is a big challenge.. gathering together what you know with the site information, fitting the jigsaw together and adapting the design to suit.. often we go back to first principles.. the SE stuff feeds into the Archaelogy.. the flooding.. it's fascinating.. and then you have to get that to work with a budget and still keep the Architectural design concept. The best advice I can give is to go though each of your design team and look for the most experienced with the broadest knowledge. Then see if they are excited about your project. This does not have to be the most qualified person on paper. Then ask.. will they fight my corner and pull the rest of the design team into place. You are the Client thus the big decisions will always rest with you.. but you need a good "wingman" that is invested in you and the project. In terms of design cost expect to pay more up front.. as the design progresses you can easily realise £20- 30k plus savings on a 450k refurb or the like that will basically pay for most of the desing cost. Skimp now on the design fees and you will regret. well you may not.. often folk just blame the cost over run on the poor builder who has got to sort out crap and unrealistic design on site.

Agree with Nick here.. but.. Here lies the problem as I mentioned in my earlier posts. In my own case you just don't get to have you cake and eat it. Designing stuff is my day job so its easier for me to get my head around it. I recognised that I have a big open plan floor that extends over different substructures that all move about differentially quite a lot. To compensate I over designed the UF in terms of pipe spacing close to the exposed perimeter of the building. The thermal conductivy is not as efficient when retrofitting to timber joists with screed / insulation between . Each different element, concrete slab / suspended floor has got its own UF pipe loop so I could muck about with it.. cool parts if need be and so on. However the extended part of the house is exposed to the weather. In the concrete slab near the big bits of external glazing I decreased the pipe spacing. The timber suspended floor has little exposed perimeter and thus it needs less "poke" from the UF. At the end of the day I use my own engineering judgement (how materials behave) and past experience ( have done a few UF self builds / extensions) to put something together that works well. Could I prove this by calculation.. no chance without expending some 5- 10 k design effort producing some meaningless thermal model. I also pinched design principles from some of the industrial building I've designed over the years so this gave me confidence. In summary.. I would put together your requirements and ask all the folk that need to contribute to the design.. look at their fine print.. and you may eventually conclude that with say a refurb / extension you need to take some extra risk as each supplier will put so many caveats on things you can't make them all meet in the middle. I mitigated this by practical and common sense design and some careful but practical drawing detailing.

Wishing you all the best for the transmission. Help ma boab as they say in parts of the UK. In all seriousness I think you have gone a good way towards being as open as you can, a thank you from me.

Now do you want to go the whole hog and make it building regs complaint and get planning approval for it? If you do so it could add a lot of value to the house?

What a topper of a response!

But I love her to bits and she is my sole mate. Anyway my wee car just looks like a standard car to me. Kwick fit said it might have be "modified" I think they were referring to the sound system.. I'm an old raver and like old school techo music.. the sounds are great.. like the frosties ad. Sometimes Techno music helps my creativity as an SE, other times classical music. Very happy for my best pal to have the posh car. I do worry how much it will cost if I prang my wee car.. but "we buy any car.com" don't put much value on it anyway.

Tell us what they are. There may be some fire boundary conditions or other reasons. It's not build hubbers job to second guess? Are there any fire boundary conditions for example? Yes we do but you are not providing all the facts and drawings. Do this and you will get some free professional advice and adivice from folk that have done it DIY and worn the tee shirt. Think about this.. you are asking BH folk to help you break the law and potentially put other folks lives at risk. Have another go at asking for help and free advice... everyone will cut you loads of slack and pitch in.

I've got a Seat Ibiza... that I use for my SE surveys... and it goes like stink to my surprise. I thought it was a run around.. I've never looked under the bonnet and it just looked like a wee small car when I bought it. Can't understand why it goes faster than I expect. Wife has the posh car and it goes a bit faster and that car seems to be a points magnet.

No mincing from ETC here on the pointing and I agree. NHBC recommend 40mm of a drip which is what I spec as sometimes the render etc are a bit out of line. Your starting point is to work out how you are going to insulate the reveals, cills and head of the window. Then make sure you can fix the window securely and last make sure it is all weather tight with DPC etc. It's OK to mount a window on the outer leaf. Velfac windows adopt this principle. Have a look at their detail.

Hiya. If you want a bit of moral and technical support give me a call and we can chew the fat. Text me first as you know Im a bit of a deafy.

I'll post a photo at some point so you can see where you advice was implemented! Thanks again. Do you want to come up and work in the Glasgow area?

That makes sense. I presented the maths but your reaction time is slow so yes you will probably not stop and still hit folk with enough force to hurt them.

It's hard. There are so many shades.. nightmare!

If you want a bit of free advice make a contribution to BH that reflect what you have learnt... Say nothing here that you have done so. The mods are very discreet and professional.. it will stand you in good stead. There is an old storey about business that involves a young and old bull in the top field and some young cows in the bottom field. Its vulgar so will not complete.. look it up and mull it over. That is good to hear no cash deals. Any advice you can give for build hubbers re negotiating would be hugely welcome. What you have not addressed is my question about the things that normal folk can't access. You are on the telly.. insta etc. It would be great to hear that you have done this straight off the batt without weaving in any other business interests you have. If you have done so then loads of folk would love to hear how you have been innovative business wise to make your dream a reality by marrying up all the skills you have. There are loads of young, skint but hugely talented folk on BH that have the same dream as you. Maybe you can give them some tips for free? You are clearly media savvy. I use my own name on BH as you, appreciate your commitment. I am a designer as a day job and a past ( the baldy patch and sore hips are telling me something) self builder. Now our Kev.. I suspect he may be a Build Hub lurker? BH is the real deal not for profit set up.. the cumulative knowledge on BH is exceptional.. we have Lecturers that teach folk like Kev.. highly experienced Contractors, all the professions from Architect, Geotech folk to SE's, glazing specialists the list is endless. Then we have all the folk at the sharp end of doing self builds, going to exhibitions and passing on what they have learnt. Maybe Kevin will come on BH? There are a lot of professional designers on BH who would love to get his advice. Myself not least.