Gus Potter

To my mind you are hoping you get a good brickie that can execute all this properly..and for that you will need to pay for a professional brickie @Canski may be able to give you some realistic rates. To be frank you'll need to stand over them all day long as fitting insulation properly into a masonry cavity is like buying a second hand car! Give it a miss unless you have the time! Fitting the any kitchen units for example is the least of your worries. A safer bet is to go for a TF which you can inspect, the air tightness and so on. Mind you if you have the capability to build this yourself then go for it. The big secret is to take care of your aerated blocks and condition them on site.

Thanks for the compliment, I'll take as one as you have not ripped me to death! That said the following is a bit loose for the reasons I've previously stated. Please excuse the spelling and grammer as I'm just "musing" One way of explaining this for all on BH. There are two facets to building a house. First is the construction phase. In this phase we don't want anyone to get hurt within or outwith the site, we don't want to have a fire say (that could also spread to neighbouring buildings) that will hurt folk / cause property damage. That is common sense.. but I've stated it for ease of writing. We need to separate the above posts into two distinct systems. The first is the long term fire protection, needs to last 50- 60 years, the second is during the construction phase.. which we are talking about here. It is easy to confuse the two. Call the construction phase temporary works. Now we as designers take into account, buildability for example, site constraints and how we are going to erect say a timber frame safely. @Lnp I think once you look into this you'll manage to navigate. I suspect you have not engaged a professional designer as yet that can help you? A word of advice.. you can potentially tie yourself in knots here trying to do this off your own batt.. do you want to do that? To put this into context.. It's taken me at least 20 years to even learn enough about this subject to enable me to make a reasonable general comment! In a previous post I mentioned tying of the TF frame.. this is not stuff anyone that is a busy self builder can be expected to know. Now for a bit of drama.. most folk know that if you stick up a TF next to a nursing home you should manage that risk.. an open TF can burn like fury, especially if the floors are loaded up with PIR and chipboard! These are basically a Guy Fawkes bonfire if the fire construction risk is not managed properly. In recognition of this construction phase we use different criteria and risk analyses methods. This is a cracking question! I think it will add to the cost on occasion.. say a tall TF next to a high risk building. If you are doing a TF extension on close to a boundary then yes technically it adds risk. More risk = more cost. But we must first identify what the risk of fire is and the consequences that follow @Kelvin .. but someone asked about how will Heb Homes continue to sell. MBC are another example. It's all doable.. but I think more transparency is going to be required. I know this may sound a bit bizarre but it is things like this that could force designers to start talking to each other for the benefit of the self builder. I've been around for about 40 years in the TF / self build / Contractor market. During that time eveyone has further specialised in what they do. This specialism has resulted in what we call a loss of tacit knowledege (in old money it was what your granny taught you..that is why bridges are collapsing in Spain etc. .the current generation think they are reinventing the wheel but have no real perception of risk )... @SteamyTea @MikeSharp01 comments welcome. There over time has been this passing of liability that does the self builder no good. In some ways folk on BH are conditioned into getting itemised prices for each element of the design and build. But it's like building a motorbike by buying each part from China.. the sum of the parts costs more than a new bike! I welcome the new regs that are coming on stream.. they are starting to force designers to collaborate, design safely and bring the cost down to you (BH folks) as the end user. Now. on first glance you may think that this is going to make self build cost more. I am hopefull that this will reduce cost as the new regs will force more transparency in terms of pricing. Yes self building has become a lot more complex and time consuming but there is still money to be made and the opportinity to build you dream home! Yes I'm more of a glass half full kind of person! Oh to finish. Great to see @Jeremy Harris back. I know he as asked for no PM's. Jeremy.. I'm a massive fan and thank you. I've learnt a lot from you so ta.

Call out for a washing machine repair £35.00 min. Two hours say to run a couple of cycles, say all in £100.00 Someone who knows about design (who will spend many hours putting this all together and listening to your brief) that you have staked you savings and mortgage on for £150.00 quid?

What a cracking question! Talk about putting folk on the spot! Forgive me if I don't deal with some detail or give a definitive answer. One main reason is I use my own name and while my PI insurance covers me to write on a public forum (give unpaid advice).. it's not open ended. I make some comment later that may help the self builder / folk extending say. It's good guidance. The following is some general comment for discussion purposes only. The guidance adds to / provides a methodology to support some of the things we have been doing for a long time anyway. The recent changes in the regs formalise this and aim to hold folk to account for their design, contractor to their duties and say the duty of a self builder, even someone doing and extension in timber frame. I support anything that will keep folk safe. The document is a guidance document. Many of the clauses in the Buildings regs, British Standards, Eurocodes, product manufacturer's guidance / data etc are.. guidance. But if you choose not to follow this and something goes wrong then you can find yourself on a sticky wicket as the onus falls on you, as often you need to prove that what you have done is equal to or better than the guidance. There are times when SE's need to go back to first principles and develop stuff from scratch. This crops up a lot when renovating, upgrading old buildings and say converting farm buildings to domestic use. You get funny sized cavities / flexible steel frames / old mortar and all sorts. Generally once we get into the "higher risk" building category.. could be a flamible house next door, a TF of say 3 storeys or more, close to an old folks home, a block of flats, a fuel station etc then the bells start ringing. At the concept design stage we would pick this sort of thing up.. good designers spot this kind of thing. To go back a bit let's look at what we are trying to achieve. The following list is not comprehensive and I've tried to put things in some kind of sensible order. 1/ We want everyone who works on the site or attends site to go home safely at the end of the day. It's basic Health and Safety stuff. Everyone on site needs to know what to do and where the exits are if a fire breaks out. This includes anyone working on scaffolding / mast climbers or the like. There is plenty information readily available on this from the HSE and other knowledge bases. One key point more applicable now is that a Client should aside enough in their budget to enable a contractor to comply with the current HSE regs and stipulations from the designer regarding say construction sequence. It's always been there under CDM but hidden to some extent from the domestic Client ( self builder / extender) For all on BH. When getting prices from builders it's worth getting them to itemise out a sum for safety complicance on site. This lets eveyone see that you are taking safety seriously from the outset. 2/ OK say there is a fire and everyone is off site safely. The fire brigade turn up. They need to be kept safe also. You can't have a structure suddenly collapsing on them. Now we are getting into the design / planning of the method of construction and sequence. As a designer when faced with this I would introduce this at an early stage to a Client.. this is usually an expansion of the explanation about fire boundary conditions that apply post completion. See my previousish posts. 3/ OK say we want to do a self build in TF that during contruction poses a risk to a neighbouring building? The Building regs talk about fire boundary conditions.. you can have one even if there is no house next door! Most of the time we know that the construction phase is relatively short cf the common 50 year design life of a house and can see if there is a structure next door or know if one is planned during the construction phase. 4/ Well we can look at the STA guidance for fire during the construction phase, refer to other stuff we are aware of and importanly apply common sense. Then find that we either can't have a TF under the STA guidance or it is going to become too costly to do a self build of say 2 storeys. 5/ Now we need to go back an look at the risks of the particular project. No project is without risk so what can we do? 6/ For me I look at how could a fire start. Again much of this is covered in the HSE regs and guidance on fire safety on site. But basics are no smoking, no hot work, no using a grinder that causes sparks.. no hot site lighting and managing material handling / storage that can add to the fire load (the fuel for a fire) the basic stuff. I look at my design.. Have I / will design something that adds risk? What is not so well covered is site security (your location) and the way you conduct your personal business! A few years ago we had a big problem up my neck of the woods with the criminal fraternity washing money in site security. Bills were not paid and a lot of TFs went on fire at the weekend / at night. Mind you the poor spark got the blame some of the time for dodgy site security electrics! A big risk is theft from containers. Folk use burning gear to cut the container open.. keep your container away from the house if you can. 7/ If we can't get the risk down enough (say 24 hour site security, a fire watch at critical times etc) we may then say let's put up a few TF panels and get the brick cladding up straight away to fire stop level. We may need to get some cross walls in to act as lateral support to the external walls and worst case provide some temporary protection. In summary it's about looking at the risks and mitigating them to an acceptable level. The question is what is acceptable! For me part of the foundation of acceptible is a Client that will engage / discuss, that is my starting point, rather than just "seeing me" as an unwanted expense, a route to getting BC approval and then going off an going their own thing.. the new regs are intended to put a stop to this in some ways. Some may say it's jobs for the boys! But if you get you designer in early and just talk through the job it can lead to lots of other savings and ideas that can easily offset the professional design fee. To exagerate to make a point. In item (2) I point out that we don't want the structure to collapse on the fire brigade. The structure is connected to the foundations and these can provide rotational support to a wall subject to fire @saveasteading has written lots about encastre support / wall and steel frame base fixity and you can find out more about this if you look at his posts. So now we talk about your founds / floor joist span, type etc etc.. and this leads to holistic design and cost savings. Some clouds have a silver lining even if you have to stump up a bit more cash at the outset in terms of design fees. Over my working life I've seen two fatalites and one serious injury on site (loss of a limb). Two were preventable, one was a freek of nature to some extent. I myself got briefly trapped in a tight solum space when I was a young builder (before I became an SE) and set fire to the floor above when using a gas plumbing torch.. I could see the flames above and that rapid crawl to get out stays with me to this day, worst still there were kids in the house so it was just not myself I was looking after! Uncontrolled fire is an awful thing. That's it for now @LnP

Welcome to the land of BH! It's doable! Ah! If it's any help I do this as a day job. The poor performance, basic lack of knowledge about the construction / design industry, professional standards in terms of communication from say Planners and BC is astounding at times. In mitigation they are starved of funds so there is no time for them to learn these basic skills. And the liabilities are big! My PI (Professional Indemnity) insurer has a long list of questions about just what I'm designing in terms of fire protection. They need to understand how much risk I'm taking on and their exposure. In general BC officers just don't hold the required PI cover these days. Many Architect's are nervious.. and rightly so as fire protection is linked to structural design. It might kind of work like this for Heb Homes. But they may be able to shed more light on this. It works for me. Here is a rough summary of the things we need to think about when building something near a boundary. In Scotland / kind of rest of UK. If something is closer than 1.0m from the boundary we need to stop flames and sparks from jumping over the boundary and setting light to the house next door. We call this fire integrity. For example if you have steel cladding then if the seams of the panels come apart then sparks and flames come out which can jump the boundary. Another part is what we call "fire resistance. Here we want to stop the wall from heating up so it radiates heat, like an electric fire too close to the bed. The fire intergrity and resistance are then combined to give you the overall fire rating of say a wall. That's a rough summary. If more than 1.0 m it gets easier in terms of complaince. Some structural design stuff relating to fire: The easy way to explain (laymans terms) this is that we need to make sure the structure is protected enough so you can get out if a fire starts. Hence the 15 min and 30 min you see. But we also need to make sure the structure does not fall on the Fire Brigade. Many of these folk have lost their lives trying to protect badly designed properties and industrial buildings. Here lies one big issue. There is no standard detail for this. I do a lot of refurbs / conversions etc and and many of these are timber frame / light weight construction. I adopt this approach as often I get to reuse existing founds and so on. When adding an extra storey to a building I often look at how much load I can remove first and then see what I can add back in without having to say strengthen the existing founds. But this leads to odd sized cavities (we are building off an old cavity wall maybe) that we need to ventilate. But we also need to fire protect the wall panels.. often called fire stopping. It the cavity is fairly normal 50 - 60mm I may use an intumescent fire stop strip like say TENMAT which gives me the ventilation but also stops fire spread. But this has limitations. If the cavity is say 145mm then we need to block a bit of that off ( say with good solid timber ) but still keep enough ventilation for day to day perfomance. I'm just touching on some of the complexity. BC just can't give you this kind of advice / take liability for the amount of money you are probably paying them.

Well done pletty to mull over here! Will try and respond once have had time to digest.

Yes. As Engineers we are always seeking out new ideas. @Kelvin et al. On the AI stuff. But I'm going to give AI a hammering if I have the will to live. Folk are getting carried away with this. For me it's just another IT ( computer development) that we will get used to. As an SE it may make the calculations more speady.. maybe format our reports a bit better. But having been involved in developing software that other SE's use..I've learnt that any software has it's limitations. The basic rule of new software is let's get it out there and we will sort out the bugs later. No shit folks I have been there and worn the tee shirt! Buy the time you sort out all the bugs the world lhas moved on and the investment is lost! AI will be limited by the (expletive deleted)wits that are involved in teaching it. These will tend to be young folk that have litle to no life experience. Itis potentially dangerous but they said the same about Elvis! The main stream media are making a big song and dance about this.. but to give the young folk credit they can smell shite just the same as us us older folk!

I admire your intelect, range of knowledge, what you teach and explain. Your command of English blows me away. You have a gift of being able to distill complex subjects into laymans terms. I've just learnt a new word not least. Thank you. If you are ever up in Weegie land then let me know.

Rotate the image +90 degrees. i.e clockwise. The pole plate is the ~ 50 x 50 mm timber that locks the rafter to the ceiling joist. The simplicity of this connection is remarkable but this is not taught at university... and you won't find this in standard text books. What you will find is plenty Architects / builders and other historical types talking about this but few actually know how it works @ETC fancy a go? Just kidding you.. The primary forces are the gravity loads, wind uplift, timber shrinkage and creep. Now you live in France.. so you'll have some of these stunning winding stone stair cases that seem to be supported by sky hooks. We know they work and why qualitatively.. like the pole plate above... but if you get some twat from your approval authority that says.. lets see some calcs. It is very difficu to prove it by calculation. Even when you can you find that many old buldings and their structural membesr can't meet the moderns design loadings. When this happens we as SE's need to delve deep in our basic maths, we have a look at probalility and risk of over stress. and all the while folk are slagging us off and not willing to pay for us keeping their kids safe? I've got some high end soiftware that does finite element analysis.. it could maybe come close but it could take me about a week to set up the model.. then I need to verify that my model is rational, then explain to some (expletive deleted)wit in the council what it is all about. I would not do this for less than 7.5k... UK pounds. Now imagine if I sent this stuff to your local French Authority. They would / may do one of two things. The smart folk would say.. let's see how the Scots guy is modelling this and the conditions / assumptions he is making in his model. they would use it as a CPD excercise all at your expense.. the rest would say.. we don't like Jocks so "^ let them have intercourse" Still happy to give you a bit of advice though but as you can see from the above I'm a bit of a pragmatist.

I agree. It's a good appoach to let sleeping dogs lie. The existing roof will likely be restraining the existing wall heads. Often in the Uk we used what is called a pole plate roof. Here there is a timber runner that locks the rafter base to the ceiling joist. I'll dig out a photo, not tonight but later if of any interest. The more you mess with an existing roof the more risk that it will move. If you have a period property then you get no prizes for cracking the walls! Now this may not apply to you but many old walls rely on having a good amount of compressive load from above. Sometimes we can "unload" an old wall and we think that will be good for it.. but in fact it can be very bad! At first glance this is counter intuitive but the compressive load keeps the say soft lime mortar in compression. Masonry walls perfom well if they are subject to reasonable compression. In laymans terms this helps keep the joints tight., and by default water resistant. I could show you the maths but lets stick to concept ideas for now.

I do a good few attic conversions in my day job. Some require a bit of ecclectic engineering / design and that often drives the viability in terms of cost. Many Architect's just don't have the SE knowledge to excecute this at an effective cost. I'm surprised that you have to go through and Architect's studio. I carry £2.0m PI insurance but most of the Architect's / domestic light industrial Architectural designers carry less than a £ 1.0m as a day to day working policy. This reflects the responsibility that SE's carry to be blunt! To be fair I have a big tool box of stuff I've learnt over the years . I know when I have a good chance of sistering joists, when I need steels, can I use cold formed steel, glulam beams, can I plate up the existing roof joist connections with plywood and glue.. can I just shift a bit of load elsewhere in an old roof to make it work? will it be ok just as it is! But here we need to look at how an old roof is made. Is it a true cut roof or does it rely on nails that may have corroded? It's not just the structure per say.. often you have drainage requirements that has to be weaved about the structural members. I wear two hat so I'm an SE and Architectural Designer. But.. I also collabrate with Architects where I just do the SE stuff for them. What they do is to say.. hey Gus.. I want to do this project.. can you have a look over it and see where you can save some cash..squeeze in the stair case so they can then go back to the Client and say.. our SE has had a look at this and we think we can do x, y and z Arcitecturally and here is how we are going to make the savings to pay for it. This can mean getting a traditional joiner that has been on their books for a long time and the Architect wins the job on their access to the right contractor and SE. Now here is a small example. In a traditional roof you have some vertical struts. In Scotland we call them soldiers. These struts are commonly 1/3 checked. The check acts in direct bearing..timber to timber the other part has commonly three nails only that stops the rafter lifting up. In other words this simple joint is more comlex than it seems at first glance. One part of the joist resists wind uplift ( the nails) the other say downwards snow load. Once you are aware of how a checked roof joint works you can begin to appreciate how skilled the joiners were. That's it for now.

You are paying the fee. There are plenty SE's about that take the view .. pay me a fair days rate, recognise my skills and craft. I run my business not on price but on my skills. For all on BH you'll be happy to pay £250 and hour to your lawer but get an upset tummy if your SE charges you 80 - 100 an hour.. but your lawer is not going to save you say a week on site for a couple of men that will run up a bill of 1.5k a week? An Architect with 40 years experience behind them will save you piles of cash too! If they can't then get rid and come to me @ETC About every month I have someone that declines one of my briefs. The reason.. I can get an SE for half the price.. but I know that the builder is going to rip the absolute pish out them.. I also see some of my competitors SE desings.. and sometimes they are downright dangerous! Yes the beams say in themselves may take the loads but the buildability / sequancing can't be realised at an affordable cost...and that makes their design dangerous! They know it, they know I know.. and they shite their pants when I get called into to inspect their design! cause I'm a builder come gamekeeper! Scottish SER scheme.. story for another day.. but maybe that is the police policing themseves? Surely not! Does that mean that Scottsh SE's are better than Irish or English SE's? Funnily the Scottish SER Scheme is an English registered limited company.. the smell of roses is overwhelming! @Garald Spend some time finding the right SE for you, don't go for the cheepest, find an honest broker, go for the one that will deliver what you need

I admire your tenacity and interest in sturctural enginering. But here is a bit of tough love. It will take you about 20 years to become competant to design this kind of stuff economically that you are wanting to do. Find and pay for an SE that likes doing the things you are trying to acheive and you will save loads of money. Your chances of producing a set of calcs that can even begin to back up what you are doing is close to zero. You will have to also learn about wind and snow loads not least. Then you need to trace all the loads down to the founds, prove the load path / building stability / fire protection and check everything below that! Yes you may be able to read books and work out the forces in the members. That is good fun and will introduce you to the tehcnicsl terms. Anything you do is time well spent. But you'll need to know how to work out the wind, snow and gravity loads. You'll then need to establish the deflections. Next you will have to quantify your connection design. This is going to be harder as you are marrying into an existing structure. To put this into context. I was a builder for 20 years, then went to uni at the age of 40 to become an SE. I'm now 60 years old and now reasonably competant in this kind of structural design. But every day I learn new stuff.. Give it a miss and spend your time researching insulation / sourcing materials. Sorry to say it. If you fancy being a Structural Engineer then it is a great job. My journey has taken me into the Architectural and Conservation side so now I call myself a Structural Engineer and Architectural Designer. But seriously it's taken me some 15 to 20 years to develop my basic skills and that is off the back of me being a local builder for 20 years before that! Now I'm no thicky on paper. I have a Masters degree with distinction and won the best all round student prize at university. Frankly you can become a Surgeon faster than an SE! but that goes back to how many folk you get to kill in one go! see below. Per say it is a very responsible job. It's the kind of job that keeps you awake at night! I often say.. Doctors generally get to kill one person at a time but an SE is able to kill lots in one go! If an Architect makes a bit of a bollocks of it then your building may leak water / be cold / condensation or look as good as you expect.. yes you may lose some money but you won't get killed! If there are any teenagers (parents) reading this or folk that are stuck in a dead end job.. My advise to you is choose a study course that teaches you how to teach yourself. @SteamyTea et al. Probably the thing for me was that the folk that taughtme enabled and gave me the tools to teach myself. I love cooking. I could have pursued something completely different. When I was a builder I did not know how to teach myself! @SteamyTea @MikeSharp01does this make sense to you?

Glad to see you back. Gus.

Sounds a bit too cheep to me at 900m? That's half mile! That will need a big cable to avoid voltage drop, a good few lecky board guys to unroll the reel and some fancy connections at each end.. all for 3.0K? Have you sorted out any wayleaves you need?

Thanks for the compliment, much appreciated. The amatuer point, well I still qualify as that as this sort of stuff is complimentary to my day job.. SE / Architectural designer. Great succinct writing. The house I look after is big. I forgot to mention that it also has a large "garage" which has space for a few cars and a games room. That has it's own boiler that runs off oil. I think Clive's thinking was to have options.. switch from a big LPG tank to oil if the price changes. He really future proofed the place. But that comes at an upfront cost. @MuellarIn terms of protecting your asset (when you come to sell) then connecting to the grid, even if you have a small main fuse is probably the sensible thing to do. But you do have the standing charge. Much will depend on the value of the house cf the capex cost of connecting to the grid. That said if you are a bit strapped for cash then you could set up your own of grid system and get grid connected later, so long as you plan for it then you may have options.

Thanks for the heads up. I'll mull it over.. see if I can come up with a anything that may be worthwhile, most of you have already claimed the good ideas and given sound advice in my mind. For all. That's the great thing about BH.. the sharing of ideas, a bit of maths, design principles, Architectural, Goetech, Electrical ( long list) design, innovation and not being to afraid to be off the mark from time to time. I always appreciate BH as if you're a bit off or say something silly you don't get ripped to death.

Feel for you. Best to redo it in the long run.. unfortunately.

Hi all and @Muellar Here is a bit of a story but some ideas for you to have a look at. I'm and SE and Architectural designer but here is some of the stuff I've picked up along the way. Servicing a site can be expensive.. a decider often. I look after a house for a great friend who's husband died. It's around 500 - 600m^2 and well out in the country. We ( the husband who was the techy guy) both did a self build at the same time (mine was a lot smaller) but Clive (the husband) who was a scientist / technologist say like @SteamyTea and @Alan Ambrose were well ahead of his time and brought loads of info to the table as he use to work in Finland / Sweden etc. In some ways the bigger the house the easier off grid is to do. The house I look after also has some 5 acres of land so plenty scope to "do stuff". It was Clive that got me into UF heating systems /off grid stuff / electrical diversity and trying to get the maximum kVa out of a transformer on a pole that is several hundred meters away (voltage drop see later)... and that was 30 years ago. This worked for us as we were well out in the sticks and we use to have power cuts for days at a time when the temperature was regularly -15C and at one time hovered between - 19 and -23 deg for three days in a row.. even our drink froze / the diesel vans did not start, my German Shepard got a bit cuddly and that was a great experience big dogs are warm! This is the Scottish Borders I'm talking about when we used to get hard winters. Basically we flew by the seat of our pants and hoped it would work in the Scottish climate. We had no internet to research and a set of Y fronts each! they came before Speedos I think. .. for the younger these are male under garments that we use to wear. I'll come to the off grid stuff which I love later.. on my bucket list. Ok what Clive did was to have a LPG gas generator for when the power went off. My power cable which was right at the end of the line was a 95mm^2 aluminium three core cable, each core! What the electricity board was to connect all the cores together so we got single phase (220 -250 volt) but delivered through each of what could have been a three phase supply. This mitigated the voltage drop. But the big cost saving was me digging my own track and backfilling. DNO obligations, diversity and demand: My level of understanding is pretty basic @ProDave may chip in to clarify. Also @Carrerahill is off line at the moment, but I'll see him early next year and he does this stuff as a day job. Anyway @Muellar I would come at this from a different direction. Generally the cable that comes to your meter is protected by a main fuse. These tend to be sand fuses and work in a different way from everything after, usually the tails to the meter. I'll call it a sand fuse as there is a table in BS 7176 that lays out how they perform. @ProDave can you correct my interpretation if my laymans explanation is off the mark? Now lets say you have an 80 amp sand fuse. That is the one in the meter box that has a seal on it. Up stream you have a DNO cable ( belongs to the lekky board) which they are interested in protecting and everything up stream of that only. Your in house system is of little interest to them. Now a sand fuse / breaker does not blow like a fuse / MCB you have in your consumer unit. I'm trying to find the BS 7671 table but you could draw several hundred amps through a sand fuse over a few seconds before it blows.. and that is why you should not tamper with it!. Sand fuses work by heating up and then they blow, the sand stops the fuse blowing when say you blow a socket in the house and you get a surge of current.. but the MBC's etc on your consumer unit stop you getting killed as they trip quickly.. hopefully. The stuff in your consumer unit works on miliseconds.. the sand fuse in minutes. Now say you had an 80 amp sand fuse and you were drawing 100 amps.. it may last a few minutes before it blows. The whole objective of the leccky board fuse is to protect their equipment and not yours. Where I live here is a local transformer that has a fuse rated at 600 amps. but it I think serves 10 -15 houses. The electricity board apply diversity depending on the number of houses. Again their fuse at the sub station is not the same as the ones we have in our consumer unit. Ok lets put some sums to this and why. Copied from internet to be lazy.. In the UK, the declared voltage and tolerance for an electricity supply is 230 volts -6%, +10%. This gives an allowed voltage range of 216.2 volts to 253.0 volts. Now your supplier has a legal obligation to meet the statutory voltage range... and that is easier said than done! @Muellar this may lie behind the quotation you have. Try and get to the bottom of this. If you have long cable you get more voltage drop prid pro on on the cable area. It may not be the amount of kVa that is the sticking point... could be their obligation for voltage? If the cable is too thin / long it causes a voltage drop that could expose your suppplier to a claim if your appliances stop working. The sums are Kilo Watts = Volts * Amps. Say you have a 15 kVa transformer up steam. It's the current that overheats a transformer generally. How many amps could you draw if you were the only customer at 216 volts. ? 15000 watts / 216 = ~69 amps continuously... like for an 20 min to an hour say . Transformers are designed to cope with a surge in loading and that is why they are oil cooled and have fins for example. But if there are other folk using the same transformer it gets more complicated. A good example here is that you get a DIY guy that likes to do a bit of welding. They may be drawing a lot of amps but only for a few seconds. In summary I would try and understand what is lying behing the quote from the Electricity board. Most of their Engineers are quite helpful and will be happy to share their technical knowledge. You could ask the question.. can I have a 40 / 60 amp fuse, all sealed so it protects your network? Funnily they may be more than happy to engage once the find out your plans for off grid / with a bit of back up. They may support you a lot as they could use this as part of their environmental accreditation? Sell it to them! Write to the head honcho! Many ex council houses have 60 amp fuses so this is quite common. @SteamyTea has done a spread sheet on diversity.. but I would start with the main fuse to get this issue out the way and then you can play with you off grid stuff to your hearts content. To finish the DNO . I would love to have another go at doing an off grid house. OFF grid! Love this but the key for me is to do it and still be able to sell the house when you move on. Another poster has made the point that it is a neice market. True.. but if I was doing it I would keep it as simple and stupid as I can and keep some data on performance and an operation and maintenance manual. Make sure you future proof things like underfloor heating pipes.. the things that can't be easily changed. @SteamyTea Combined heat and power is fantastic. If you have a bit of ground then grow some willow, encourage wildlife and as it grows like fury it could well be enough to keep you warm in the winter. I'll need to stop here.. but @Muellar love your idea. Don't forget.. you can write to the head honcho of the leccky board.. lay out your case and they may suppport you! Get your ducks in a row and you may get a nice surpise and support.. this lunch won't be free but..

Often I may come over as a bit of a crusty / sceptical. In mitigation I designed and installed my first UF heating system some 30 years ago.. long before this came more main stream. I'm an SE and designer now.. still learning lots. But many of my Clients are folk that want to build say an extension (some are big mind) the odd new build and some really big barn / church type etc conversions. Most don't have a bean to rub together.. every pound is a prisoner! They have a mortgage and want to protect their asset. Often I say.... hey look you can have fancy controls, systems but lets also look at the value of these when you come to sell. Lets also look at the maintenance costs.. the reality of sticky valves, ducts getting clogged.. who can mantain all of that and at what cost. For example I have some Hive controls... nice graphs on my phone etc but if I want to move house it's difficult to transfer the ownership.. in fact a nightmare. Now many modern systems have software, controls that are difficult to maintain after five or so years. Now if you have plenty of cash to splash and want to make an environmental statement or just like techy controls then on you go as far as I'm concerned. If you are happy with the maintenance and potential loss of value when you come to sell. If that is what you want then I'll get that into the design. Mind you during the design process you may change your mind and come round to my way of thinking! Especially once we start to look at build cost /benefit in detail. This is a good point. Old crusty ends.

Now here is the rub. Personally I would live in a house that has some element of air heat recovery in terms of ventilation at a push. But not having windows that open is beyond comprehension. What happens when you have wet dog, want to dry some extra washing on the bannister..or just want a blast of outside air. This is not a home to me.. it's an extension of a crappy sanitized office. Ok you want to have MHVR and a wood burning stove. But I will bet my last cent that you won't change the rope seals every year on the stove door! A rope seal kit is about 12 -15 quid.. but most folk won't do it. As @SteamyTea says.. these wood burning stoves can be a killer. Always have a CO alarm in the room. Design your house and systems to last and look at think how you are going to maintain it and the cost of that. Be practical and not just aim to meet the regs. That is good design that will protect the value of your property and make your effort worthwhile and rewarding in the long term. Remember when you come to sell, some hard arsed surveyor is going to look at all this and may well write down the value if they can't understand what you are up to! This is not Fred Dibnah.. folk need to get a mortgage. Does any one think the same calculations and controls will work the same way in 20 years time? Any takers?

I love @SteamyTea post above. In a few lines he spells out what you need to do and why. Don't forget the saving that you will make on the standing charge for gas and electricity.. it maybe only a pound a day but that could pay for maintenance of a generator. changing the filter and so on. That's my tuppance! Combined heat and power (CHP)..it's a no brainer in my mind.. there is a massive amount of heat to be extracted from the exhaust gases of a generator. Mind you it needs to be done safely..I would make sure I put all that gubbens in an out house. I think this may be an advantage prid pro quo.. provided you design your house more as a box, like a long house.

My thoughts are. Safety on site is paramount. This is works on an old unstable structure and this happens in real time. Sometimes it is not possible to safely brace a structure during demolition and you need to take it down to ground level. This is good evidence of you working safely. Did you leave the existing founds and masonry below ground? If so then it is argueably a repaired wall rather than a new wall structure. Let's see that photo they have of a "cleared site".. to qualify as a complete wall removal they must have a photo of the ground from above.. rather than just one taken from an oblique view! Wall removal means all of it right down to the top of the founds! Complete removal means the founds too. Bet they don't have a photo of that! With my SE hat on. Now you have left your neighbour with a potentially un supported party wall. That party wall may have a chimney breast. If you are end terrace then your house (and the roof) may have been butressing the rest of the houses in the middle.. I could make a bit of hay with that as an SE. I would go back and distill down why you did what you did , why you did it (on advice from the builder and BC) and then maybe get an SE to back you up. If there is still some evidence that an SE can work with then they may be able to help. In summary I would get all my ducks in a row before responding to the council. Ideally any response you give has to force them to incur expense (eat into their time..) or take a pragmatic view and that will concentrate their mind. The low level planning / BC officers have managers who look at the cost / time sheets.

Hi Joe. Have a look at how an OH cowl works. When you live near say trees and say have a down draft (positive wind pressure on the roof) the vertical sides still cause a draw due to the Venturie effect. It works in all directions wind. I think it's rare that these cause "whistling"

No because you have not provided any drawings! Fesse up and share your drawings. Folk will then chip in and in return we may also learn a bit from you. Them's the rule of the game!