Gus Potter

Possibly not! Have you commissioned and run your UFH for a few weeks? If I was working for the flooring contractor I would be aware that the underlying structure also has to condition, move about a bit, it's not just the screed. They are just getting paid to lay the floor? But maybe being sensible. If something goes wrong then think about it from their end, put yourself in their shoes and work back from there. They could be faced with a massive hassle trying to prove movement is also related to the structure and not their fault. To be blunt, the suppliers of flooring and the installers have so many caveats, not least min and max floor temperatures, which are hard to achieve when you have congestion of UFH pipes. Sometimes you have to make your best guess. Anticipate where movement will occur in your particular self build and lay the flooring accordingly. To make things a bit harder, it's often the summer that modern highly insulated TF house expands as the UFH heating has been off, particularly if on say a concrete slab, this is counter intuitive!

The soils are just above the plasticity A line, not much to worry about. Lots of rafts get designed with an L shaped building, we design joints for this and make sure the super structure can cope with anticipated movement. The allowable bearing pressure is good at 115 kPa, a standard benchmark of 100kPa is a good comfortable reference point. Where does the water table sit? You probably need to post the full SI for the best feedback, there will other stuff buried in it that you may not have the experience to be able recognise it's importance.

You did, no offence intended! I layed in a bit as AI is more dangerous than not if you try and get it to do SE stuff.

Great post, very informative!

Now by now you should know that there is no way any of us that can take a punt on this. Post your geotech info, a site plan etc. You know the rules, the more info you provide the better quality response you'll get.

Reading a lot of these posts it's pretty clear that that many on BH don't have a high opinion of folk like me who design as a day job. I can see many professionals have lost their compass and are not delivering value for money and are not that good at running a business, hence the poor service delivery. I've been in the construction industry for over 40 years, 20 spent as a contractor running my own business' , did my own self build, really pretty much all by myself on the tools ( took me three years) then off to uni to be an Engineer, now for the last ten years I wear two hats as an Engineer and Architectural designer. Thus have a fairly rounded view of the in and outs of this. I can say that in the last 20 years there has been a race to the bottom, not just from designers, but also say the timber frame suppliers, ground works designers ( UFH and rafts etc) and designers who think that if they curtail their design brief, caveat it a lot the money is going to flow. But in the long term it doesn’t, as often the key to good business is repeat business, recommendation, even in the short term cutting you brief down often leads to problems, queries, design mistakes that just eat into your profit and leads to potential claims or Clients rightfully withholding money. Ok, lets look at some financials. The bottom line for a new self builder ( not someone who works in the trade with contacts) is the tendency to split each element into work packages, say foundations, timber frame and roof ect. Each package supplier takes the cream out of the job, leaving nothing for the self builder. Then you have planning and BC regs on top not least, that all adds to the cost. I work on a lot of projects where I'm involved holistically. I work very closely with the Client, not just as a designer but also do hand holding and participate in all of the design. Now to be blunt. Say for a self build the design fee is £10k. An experienced chippy ( joiner may cost you £250 a day, a labourer £150 as day, total 2.0k per week. All I have to do to wash my face is to save you a few weeks, just on the labour alone and I have well and truly washed my face! The pendulum is swinging back where folk are clocking that we need to "go back to the old days", but now you need someone like me who can cope with the modern code requirements for example, and the modern way of doing business., much less trust and more hard arse stuff. I get this kind of business where folk are happy to pay me a bit more as I can guide them, hold their hand and most importantly we all have fun, we do whacky designs that you only get to do on self builds! We also tend to avoid " work packages where we can, say from MBC et al and keep the cream to ourselves. This also often helps cash flow and gives the Client more control on day to day site activity. Now in the round if you want to make some money then try and find a designer like me that is local to you, with good contacts.

In my day job I sometimes ask AI for it's calculations for a bit of fun! A lot of the time I find it's completely wrong! I checked a beam design against AI and found it to be a factor of ten out, on the unsafe side. One of the bits it missed was the destabilising loads ( an unrestrained load applied to the top flange) loads, the lack of adequate lateral restraint and the support conditions, all that lead to is being miles unsafe. Now AI aggregates information, you could have ten undergraduates all uploading their student projects and AI thinks.. this is right, but it's dangerous bollocks! There is good reason for BC to reject you! If you want to use AI to generate calcs then you have to be competent enough to make sure it's not rubbish. By all means use AI to do the donkey work for you, but unless you know what you are doing, have the knowledge to understand what the calculations mean then you are an idiot!

You know the answer don't you! You have two choices, let the render progress, but the window frames may not be fully sealed. In reality, have you checked your window contract fine print as to what length of guarantee you have on the glazing units. If you use good mastic the frames should be ok..pragmatically. But again look at you warranty, often now the sealed units are not warranted for the same length as the frames. If you get a failure in a sealed unit your warranty may be rejected if you have not fully sealed the surrounding frame. There are no friends in the desert these days, check the fine print on the window warranty!

In the"old days" A first time self builder with no experience could save at least 15% on the build cost of a house. Now in the old days the market was rising, thus the value of the property also increased by on average, say 10%, over say a 2 year build time. You had to be a complete idiot to lose money on a self build. So even if you were not that good your self build could return a tax free return of up 25%, but nine times out of ten you would not lose your shirt. The market has changed a lot. @saveasteading who has decades of experience pointed out.. and I agree, much of the profit for the volume builders now lies in the land transaction, the actual building of the houses are not the main profit element, the house building is just a means to and end, basically a bit of a hassle! Now if you buy a serviced plot on one of these serviced schemes, the seller (developer) has already taken off the cream of the profit, you as a self building then are looking at marginal profit, but carry much more risk. Self building in this case is not going to make you lots of money, it may give you the house you love though and if that has value for you then it's viable. Now say you do a house that sells for 300k. You'll be lucky to clear 20k after all the taxes etc if you sell it on , if your motive is to make money, you'll have to risk dealing with a builder, a huge amount of personal time.. etc.. the reality is you are likely to be better off if you just do a Saturday morning shift in Aldi, you may even get a pension contribution! I've had the good fortune to talk and meet with @Square Feet who has some ideas about how we get back to making self building more attractive, not least financially. It's early stage ideas, will take time to develop, but looks promising. The reality at the moment is for your average self builder the financial risks are high vs the rewards. There are still a good few very well off self builders who don't really mind if they make money of not. But the whole idea is to encourage young folk to self build and improve their financial health which results from their own hard work. But as above.. it really is the case.. you are better off at times doing a Saturday shift at Aldi!

Your proposal invites discussion, that in itself is healthy. I think it's fair for you to ask the question, most of us on BH won't take a negative view of this as you are exploring if you can benefit the self build market, and if you can make a living out of it and a bit of money then your are justified, a fair days pay for fair work. Here is bit of context and bit of my background. The first 20 or so years of my career were spent being a builder, some of that was building houses for self builders. I had generally 6 -8 full time staff then sub contractors. Depending on the time of year I may only have had four subbies, then at times up to about twenty folk working on one site. To keep them all working I would normally run one big project and say a couple of extensions, attic conversions at the same time. This allowed me to manage resources, deal with changes, cash flow, maybe planning and BC delays. You should be pretty familiar with how this works given your background. When I got to near 40 I could see the writing on the wall personally. My wife and I parted, my German Shephard died and I was left living in my lovely self build on my own with this huge weight on my neck of the business and my duty to my employees. I shut the business, paid all my staff the redundancy, phoned my competitors, told them I was chucking in the towel and pleaded for them to take my lads on. Some did! Now I also squared up all my builders merchants.. some told me, even my accountant.. you are limited Gus, if you walk away you'll be at least £100 - 200kk better off. But I paid the money as I knew my personal reputation can't be valued. Now I was lucky as I sold everything just before the 2008 crash. I then trucked off to university to become a Structural Engineer, graduated, trained and now my consultancy is in October this year going to celebrate it's tenth anniversary. But part of my success is my contacts from the old days! I am still in contact with my old suppliers, they give me names of good creditable builders, as they remember I squared them all up. One of my ex employees is now a BC officer in my local area, his wife, who used to inspect some of my project is now a Senior in BC. They are consummate professionals and remember me as "not a chancer". In summary, my own view is that if you want to build a sustainable business in the construction industry it's going to take 5 years living on the edge, another three years to stabilise, it's really only in the last couple of years that I've felt I've arrived, lots of repeat business and a huge amount of experience under my belt now.. 40 years! Ok, the above is not a rant.. it's intended to let you see there is no fast buck here in the construction industry. Developing an app is not going to work long term, unless you have lots of contacts and an already established business that brings in the bread and butter. Let's say you are digitising and facilitating via an app the procurement and build process, that's just using modern tech, the game remains the same and the profit loss sheet still stacks up the way it pretty much has over the last 40 years. The tek has changed, but the fundamental principle of turn over is vanity, profit is sanity has not changed, you may also want ( I suspect you may not) but just look at Ruskin the common law of business. But the bottom line is that it looks like you want to project manage, use your QS skills.. with a fancy app. To make a living out of this, you need do the basics very well, get repeat business, you'll need to have lots of contacts, cash in the bank, be legitimate, have insurance etc, and be very good at what you do to be able to justify your 10%, your app ain't going to cut the mustard, the app is your potential cream, your USP that delivers that extra profit. I think you need to have look at your business model in term of the app. But if that stacks up for you then it would be welcomed by not least myself and folk on BH.

Great post and lots of info, well done you! Spend time finding the right SE, that has deep knowledge, is pragmatic and understands holistic design. That means they could swap hats and be an Architect not least. An SE like this is going to cost a bit, but it will be the best money you spend! SE's like this also act as an advocate for you, will hold your hand and guide you through all the other regs and sorting out a builder etc! Try and find a local SE, not me! as I'm too far away from you to be able to come to site on short notice, not least!

Thanks mods for removing my drawings with the Client info, you have saved the day at my end! Reposted below, redacted:

Here is the roof plan. I've screen shotted it, you won't be able to read the detail but can see the shape. Each cold formed cee was a different size, but cf providers can handle it provided you give them a schedule. All for £1552.00! The schedule looks like this, but if the walls are parallel then it is much simpler as all the cees are the same length. I would explore using cold formed joists, creating the fall can be really easy!

You'll only learn this kind of nugget stuff on BH from the likes of Nick. You may think.. well I'm not going to let the floor socket "take a drink" but.. The spark may also want to change the cable rating anyway as it's not say in a wall. Electric cables are sized partly on not just the load but also if they are surrounded by insulation, or near to say UFH. Fundamentally we don't want them to heat up too much. Thus what Nick is saying also make sense when we look at the electrical design holistically, and that can save cost later on. Thus, why not adopt Nick's suggestion, as the spark will insist that the wiring up to the floor socket is to spec anyway? It's just that last nuance that Nick is bringing his experience to bear.

I appreciate your desire for level and diligence. Have you considered. If you have an existing house. How level and undulating all the other floors are? If a new house then it is going to take time to bed in, settle. To provide a bit of context. Often as an SE I'll start by designing a house to settle no more differentially by 25mm! Then refine depending on the finishes and how tolerant the structural frame is going to be in terms of differential settlement. A Swedish log cabin might shrink by 75 - 100mm! I would give the floors you have laid so far a "walk over test" not by you, but by visitors. Ask them if they notice much level or issues with flatness. Glancing light is always going to show up even tiny changes. This is building, not eye surgery!