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  1. @Jaqueslecont did the consultant give a view on the viability of a class Q application? The barn is of sturdy concrete frame construction and AFAIK there's nothing in class Q about a floor. Probably 99% of class Q buildings would need a new floor. There have likely been similar buildings approved for class Q, though perhaps would have had some brick or concrete infill between the columns. Perhaps you could ask the consultant about the chances for class Q if the farmer were to do some minor renovation to their barn before any class Q application was made? Again - do not speak to the local planners. Class Q avoids all these issues of the local Lord maybe being able to see your washing line if he stands on his grade 1 rooftop with a telescope. There is perhaps the issue of the frame. Those type of buildings were likely not designed to last for long and you might want to get professional advice on its likely lifespan. I guess once a house, the concrete would be much more protected and so increase its life? You might also have an issue with insulation under class Q since you'd want that on the outside, thus fractionally increasing the built volume. One possible approach is to get class Q and then having established the principal of a dwelling you make a full application for some things that would make it 'better'. Having class Q IS a material consideration in a full planning application, so they are required to then explain why the class Q version is preferable to the full version you propose. There's also the paragraph 55/79 approach but that's very expensive.
  2. kxi

    Portal Frame House

    Hello, only just got initial costing for these. Expensive. Estimated price is £7,000 for about 24 x 50mm thick armatherm FRR pads. So £350 per pad. Seems *quite* a lot. This was an estimated price from the steel frame supplier. Our building is unusual in that it has so many, so would be less of a cost in something more a normal shape.
  3. @Jaqueslecont Yes no walls is usually a problem for class Q, following the Hibbitt high court decision. Best bet is to ask a local planning consultant and NOT the local planning office. The local planning office will almost certainly say no to anything you suggest and may then use your discussion with them against you in future. You may find the council has online guidance on class Q, and past decision notices will also give a guide. Martin Goodall's planning law blog is good though can be hard going. Refusal based on car usage is classic. Because of course no-one within settlement boundaries ever uses their car...
  4. kxi

    Portal Frame House

    Just came across this kingspan case study using insulated sandwich panels on a French house, which I'm pretty sure is the first use of them on a purpose-built detached single dwelling I've ever seen https://www.kingspan.com/gb/en-gb/products/architectural-facade-systems/case-studies/maison-if Visually I'm sure it's not to everyone's taste, but a bold choice. Intersting that kingspan seem to be marketing it, suggesting they see potential in the residential market.
  5. kxi

    Portal Frame House

    @PDR checking notes, it looks like the SE was slightly keener on precast than metal deck for the 5m spans we needed, in terms of overall weight and and thickness required, so that probably influenced it. Metal deck needed propping for 4 weeks but that wouldn't have been an issue in our case.
  6. kxi

    Portal Frame House

    Ah. I'll be asking you lot of questions then. Yes, that's our plan, but it still leaves a large void (200mm ish?) between the external panels and internal board that I can't help thinking should be better used. 1,000 small cupboards perhaps. There's also the issue of dealing with flanking sound coming through the void between the rooms, so we will either try and bring the stud walls 'into' the void, or stuff it with something at the internal wall junctions. Havn't really though about that yet. Yes, but went with precast for perhaps not good reasons. Our main aim is to reduce head height and with precast I found the 'slim floor' method to sit the precast level with the steel beams. With precast sat on the bottom flange of the beams. e.g. I saw this first with precast and I think the combination stuck with me. A metal deck with cellular beams version: https://www.kloecknermetalsuk.com/westok/products/ultra-shallow-floor-beam/ I think I was keen on precast hollowcore because: - I was (naively) concerned about longevity of a metal deck vs precast i.e. once the exposed metal starts to go, presumably that's it? I suspect this isn't an issue in reality. The first floor will be over an agricultural space but it's unlikely to ever be a corrosive environment like cattle, but precast felt safer. The soffit is in any case covered by 150mm of insulation and fireproofing - It may have been we could get a slightly thinner floor with precast - don't remember - The idea of how hollowcore works was so clever that it was seductive - I never costed the two - had I done so things might have been different, but precast didn't seem so expensive to be a problem That's very helpful thanks, though I think now we mentally switched to the KS1000 DLTR 0.8s we will probably stick with them. We only need light not ventilation. The plan wasn't for regular opening rooflights but for a 1x20m strip of glass roof set above a long corridor. The plan was to use lamilux PR60 glass roof set into the panels for this, but a) expensive b) lots of teeth sucking about how to fit it. There was a solution but no-one was confident (see below) c) big solar gain problem that can't easily be mitigated So we're instead planning on using 6 or so KS1000 DLTR 0.8 panels. You really can't see through them, but they are much cheaper and easier to fit, and have a diffuse light without as much solar gain.
  7. Isn't it a requirement to connect to the mains sewer if any part of the building is within 30m of a mains sewer? This is mentioned on: https://www.wte-ltd.co.uk/septic_tank_general_binding_rules_2020.html https://www.owlshall.co.uk/sewage-treatment/knowledge-base/environment-agency-installation-permission/
  8. @TomBee Hello, sounds great. I would strongly advise not to speak to the council at all until you are much further forward with the project and you know what to say to them. Much better to engage a local planning consultant, ideally one with experience of your kind of situation. There was a long thread about this issue with Sensus a while back, but in summary, it is likely that your council planners will be totally opposed to any rural development at all, and green field development especially. Anything you tell them will likely be used against you to prevent your development. I also suggest not spending time & money on architect concepts until the planning situation has been clarified by the planning consultant. It may be that green field is ultimately not feasible and you have to consider conversation of an existing farm building under class Q. If you have a family farm this sounds like it might in theory be possible, though for sure it's going to be a different proposition than new build in a field. Something like para 79 is also an option but is likely a long and expensive one.
  9. kxi

    Portal Frame House

    @PDR Some overall background on our project - before we had settled on a build method. https://forum.buildhub.org.uk/topic/7201-hello-from-berkshire/ Steel frame with KS1000 cladding was definitely not what we started out considering, but various constraints pushed us that way and now we are committed - but nothing actually rising out of the ground as yet. We considered I think every building method known to man. To be honest at the stage you are at - I would not get wedded to a given build method. Realistically the planners only care about the outer skin rather than the internal construction. The overall build method: Hot rolled steel frame with a first floor of hollowcore + structural topping. Roof and first floor walls clad with KS1000RW 150mm quadcore - so the thermal and airtightness layers wrap around all the habitable parts of the building (mainly the exterior). I.e. first floor walls from outside to in: kingspan panels (150mm) - big empty space - inner plasterboard. So it is still fairly simple at least Ground floor walls are non-supporting (steel frame does the support) and are block skin with timber frame inside infilled with PIR - our ground floor walls can't be kingspan panels as they have to have fire compartmentalisation against some barn areas (which likely won't apply to you) First floor soffit and ground floor over slab insulated with something like Kooltherm - again - the thinnest we can manage Loads of giant pad foundations set deep in the ground (we're on clay + chalk and also have to go below the existing building foundations), then a big slab over the top of that Reasons why we went with steel frame + cladding: Head height - planning means we couldn't go up and so we needed to save every cm we could and the KS1000 is about the thinnest super insulated roof we could get. Though we're actually now putting it on huge wooden purlins so it's not that thin... Also a mass timber frame like glulam would have meant beams that were far thicker than steel and so head height problems. Concrete first floor - a large part of the ground floor is agricultural use - so could have all sorts in there. So we wanted a very solid fire seperation between ground and first floor - so concrete. Again desperate to save head height so the hollowcore is arranged set into the steel beams rather than sat on top of them in a 'slim floor' approach - they usually use this on very tall buildings to get 11 floors rather than 10. A concrete floor is most simply done with a big steel frame, though there is some interesting stuff being done with wood+concrete composite inc CLT - this was tempting but is a bit experimental. Single supplier - we wanted a single suplier who could do multiple parts of the main structure because that gives a comfort factor to a first time self builder like ourselves. Steel frame + cladding is a common package. As it was we really did try engaging with suppliers of other systems - especially timber frame - but we were generally too odd a project I think and most didn't seem to want to engage Cost - we're getting the frame and cladding built by a firm that makes maybe 200 giant sheds a year. In theory this should be a cheap approach and working with suppliers who work to clear and slim margins. However, some of the issues applying the method to a house mean more money needs to go on designing details and other things. We are not a simple single storey portal frame, I suspect if we were you could get it down MUCH more cheaply. Weight is also an issue - a more lightweight timber frame would probably have been cheaper groundworks. Using the KS1000 in particular has big savings for the roof - the whole roof envelope is probably less than most people would pay for just a roof covering (e.g. tiles or metal sheet) BUT this isn't perhaps a huge cost in the grand scheme of things Apparant neatness & simplicity of envelope - the cladding seems an elegant and simple way of achieving everything you need in a building envelope. So simple! But, as it turns out it's simple if you want to build a giant single-storey windowless shed. Not so simple for a house... Design - luckily we don't have too many 'visual' restrictions from planning and we actually like the industrial nature. I.e. the look of steel + cladding was not a barrier to us, but might be for others I suspect had we not had some of the constraints we did, we might not have picked this method, but we might have. Some problems & solutions: windows and doors - putting proper windows in the KS1000 and having them thermally decoupled from the frame - complicated. Maybe it's just as complicated as in any well insulated and airtight house, but it seems no-one has done it before and everything feels like you are designing the first space shuttle. We are going to use the Kingspan DLTR 150mm 0.8U rooflights in quite a few places - you CAN flash in 'normal' rooflights, but it's hard and what we wanted (glass roof areas) was not going to be simple at all thermal bridging - our very weird mixed-use shape means we have numerous giant steel beam thermal bridges through the insulation layer. This is handled with liberal use of armatherm structural thermal breaks, so it's not impossible - just a constant thing to be aware of architect familiarity - Unless you get a shed builder to design it, your architect will have never worked with anything like this and there will be a lot of learning which adds cost and risk. They may just flat out refuse, not least because it reduces the flexibility they have to do architecty things. (You not be using an architect I suppose) Detailling quality - in particular the flashings - these all look kind of like an industrial unit - and there's not much you can do about it. If you like that great - but you can't really change your mind later Limited on what you can attach to the panels - they are thin steel sheet so attaching stuff to it is problematic. For example we want a few large awnings attached for shading, and we have to create thermally broken brackets back to the main frame, which then poke through holes cut in the kingspan panels - it's not ideal. I.e. you have less flexibility about sticking on lights and stuff. Perhaps not a big deal Wall depth - the panels are nice and thin for the whole envelope - but they have got to be attached to cladding rails, then these cladding rails need to be attached to the main frame. In a warehouse generally everything is left open on the inside, but in a house you will likely want to cover this all up - so your 150mm wall which gives a 0.12U ends up being a 350mm wall anyway just it's mostly hollow. Not a huge issue, but just worth remembering that just because the panel is thin, doesn't mean your wall will be Damage - the panels can get damaged by people bumping them and they are not repairable in an invisible way. I think you often see people putting brick skins in high traffic areas or on the ground floor to reduce ground level damage. As it happens we can't use them at ground floor level any due to fire compartmentalisation issues - which I suspect a normal detached house would not have an issue with Resale - metal clad walls are very uncommon on houses in the UK and I suspect would impact ease of selling. I'm sure some people would think it was great, but others might not. In the US you'd probably have less of a problem. We aren't ever going to sell, so it's not a consideration. It probably depends on how much you mind about creating a building that is unusual. Baked - Browsing the forum you will also see a potential issue with decrement delay if using these kind of panels, but....we judged (but did not calculate) that issues such as good solar shading are probably more important. I guess we can report back next year whether we've been cooked or not. Sound - kingspan panels provide little sound insulation - that's not an issue for us So in short - it might be better to think of something other than KS1000 panels for the walls if you can. You will still want to have the insulation on the outside of the steel frame though (though one buildhubber - Ian built his timber frame barn conversion inside and existing steel frame). From a planning POV i don't know. I suspect a metal roof wouldn't cause much objection, but metal clad walls might raise more eyebrows - but i wouldn't want to pre-judge it as there are so many factors there. Overall, I'd keep an open mind about build method at this stage. Timberframe (e.g. twin wall), CLT, and mass timber (e.g. glulam) all other interesting options to consider and you could still end up with KS1000 for the roof, or metal cladding all over if you wanted.
  10. kxi

    Portal Frame House

    We are building with a new hot-rolled steel frame like this, though technically it is as a part of a 'conversion'. Frame supplier is one that usually builds barns and sheds. AFAIK there is no inherant building regs issue with a hot rolled steel frame and loads of buildings of all kinds are made this way, though it will need all steel protected from fire e.g. by being enclosed or intumesent painted. The Barnhaus is an interesting concept to provoke discussion, and I think in general these kinds of building methods should be more widely considered for residential, however I'm skeptical about the barnhaus pricing and some of the details. I'm not clear whether the specific design has been ok'd from a structural, insulation, or longevity perspective. The steels are whopping thermal bridges which might lead to condensation problems, and the combination of straw and steel seems dubious and a gimmick. It's unclear how they'd planned to insulate the roof. Better I would have thought to have the insulation layer on the exterior e.g. via standard insulating sandwich panels like the Kingspan KS1000RW (which we are using).
  11. Ok, you'll have to speak to your SE about this before going further. I suspect 99.99% of reinforced concrete is concrete over raw steel so it's not a totally crazy thing to do, but I believe the depth of concrete cover is important. If you have a groundworking team that is not following engineering specifications then this is presumably an issue in itself to be addressed. In my proposal the WHOLE encasement i.e. the concrete around the steel, is coated in something (bitumen, liquid DPM, etc), which is my belt and braces solution in the event any of the concrete cover cracks after 80 years in the ground. This is also a potential fix for your situation in the event your SE thinks additional protection is needed.
  12. I'm not sure about the coating pre-encasement, but we have a similar situation that steel columns will be fixed to concrete pads about 1m below ground then encased in concrete. I was concerned about potential groundwater so asked for the whole encasement to be then coated in liquid DPM. The SE, architect and groundworkers all seemed fine with this, and no-one said out loud they felt this was over-kill. I felt that it costs little, might add protection, and you really don't want below-ground corrosion of the steel to foundation junction as you will never be able to monitor it. This has not been built yet so don't have any practical feedback.
  13. We have some large south facing windows that need shading and awnings seem a good solution in our circumstance (for various reasons). E.g. https://www.markilux.com/en-gb/patio-and-balcony-awnings/markilux-mx-3 However, the problem is we are using a heavy steel frame construction, clad with cladding panels. The cladding panels are two thin steel sheets sandwiched over insulation and so you cannot hang something as heavy as a big awning off them. So the suggestion is to attach to brackets that go back to the steel frame. But this goes through the insulation layer (about 150mm of foam) and so creates a thermal bridge, and while that's a small area it's a potential condensation point - not great on a steel frame. One option is to just use a metal L bracket + structural thermal break (armatherm or farrat), as illustrated below. But I wondered about using a different material for the L bracket that has lower conductivity, for example .... GRP? It has to be fairly long - perhaps 250mm to get through the insulation layer and leave space to attach things to You can get off the shelf L profiles in GRP with unequal legs - 300mm and 40mm at 6mm thick for example. https://www.engineered-composites.co.uk/products/grp-pultruded-profiles Which you could then cut into L bracket lengths of say 100mm Any thoughts on what material might be best? (Will be asking the SE)
  14. A few years ago I worked for a while in a 4 storey shipping container 'office block' https://turner.works/works/view/pop-brixton/ and the containers were an excellent solution here - enabled very rapid construction of a multi-storey building with multi-purpose units on a brown-field site, only intended to be used for about 5 years (though I expect it will continue for much longer than planned since Pop Brixton is such a success). But as noted above, there were limitations I think would mean it's less appropriate for a long-term residential structure and almost certainly other construction methods would last longer and be more pleasant to live in, and I'd imagine resale would be extremely difficult. While thinking about how you'd build it is the fun part, I think you'll need to start with finding a location you can build at and then what you can build there. But, perhaps building a quick 'short-life span' house on a brown-field site might be a way around this problem? Maybe councils are keen to find short-term uses for brownfield sites they have lying about? This might not be what you had in mind though. Unfortunately Pop Brixton is currently shut due to COVID, so you can't go and see what it's like. Despite having supported it at the planning consultation stage, I'll admit I was snooty about it when it opened - but ultimately it was too awesome to resist. As a working space it was fun, but there was some secret relief all round when a water leak and collapsed ceiling meant we all had to go and work in a vast, airy, Victorian corn warehouse in Loughborough Junction for a few weeks.
  15. Congratulations, sounds like you have an enlightened planning department. Hopefully more decisions like this in future. Our experience (Berkshire, Green Belt) was quite different. Class Q PD was reletively easy to obtain - did we tick the boxes? Yes. Ok you have Class Q. After that, we applied for full planning permission to modify the building shape, mainly to make it easier to build, better use of space, more attractive, etc. In the full planning proposal, the overall volume of the development was reduced compared to the class Q version, though the building was higher on one side than previously (and another side was lower). Parish council supported the proposal saying the full planning version was 'better' than the class Q PD version. However, after an agonising full planning process it was rejected. In essence because they could i.e. they did not want a dwelling there at all, and did not have to give it to us (unlike class Q PD) and so didn't. The rationale given was basically 'we don't want a house here because someone there might use a car' (true story). We decided not to appeal and instead made non-material amendments to the original class Q. Mainly didn't appeal because of the theoretical risk it might end up revoking the original class Q. Our rejection report did not consider the granted Class Q PD as a material consideration in the full planning, and so was deficient in that regard, and could have been grounds for appeal (as per the Mansell precendent). However, even with the PD as a material consideration, the subjective judgement whether the full planning design is 'better' than the Class Q design still rests with the planning department - who clearly were not going to go that way in our case. In the Mansell judgement, the planners DID think the full planning scheme was better than the Class Q PD version, and the appeal did not seek to question the planning officer's judgement on this aspect, it was just to see whether the planners were correct in considering the Class Q as a material consideration. In case anyone is interested, more detail on the Mansell judgement: http://planninglawblog.blogspot.co.uk/2017/09/can-pd-rights-represent-fall-back.html http://www.buckles-law.co.uk/site/library/planning-news/when-is-a-fallback-position-a-material-planning-consideration https://andrewlainton.files.wordpress.com/2017/09/ac0155825cacivdiv5107.pdf https://www.tozers.co.uk/court-appeal-clarifies-extent-permitted-development-rights-agricultural-buildings/ http://www.acorus.co.uk/news/detail/national-advert-class-q In our experience, the local planning department did not care at all about sustainability, other than in the reduction in car usage. E.g. the energy efficiency of the construction method was totally irrelevant. I remember Sensus - architect & planning consultant late of this parish also had similar experieince.