Gus Potter

Agree John. There a loads of folk that use ICF as self builders and sometimes I look at ICF designs and think.. that does not stack up cost wise. It's forgivable as often folk convince themselves that it's right for them, but with my hard nosed hat on I know that's not the way I design as I can see it more expensive. But other times ICF is absolutely the right way to go. As a designer I often look at projects and think, how can I get this built at the budget? It takes experience, it's not that hard though. One of my key principles is to understand the Architectural design intent, identify what is important in terms the Client requirement, what matters to them, and then check to see if that fits with the planning requirement. That's the way I design as an SE and general designer. The big problem is that folk just don't want to pay for this skill. One skill a good SE should have is to be able "knock heads together" , bring discipline to the design process. Architects are not good at this in general. Because that is a Client requirement, what is wrong with realising your dream to have something that is different and a wow factor. Now fair enough, it might turn out that the detailing and buildability is going to be prohibitive cost wise but you have to explore all the design options. In summary folks if you are thinking ICF also look as how much extra performance you get out of it for a bit of extra rebar. It's almost free money!

A basic DPM gives you basic protection, it's taped anyway to stop damp. Where are you building? Why are you replacing the existing concrete slab? Myself and @saveasteading often look to see if we can retain the slab with a bit of clever engineering. You should by this time have an SE fully on board giving you practical building advice and showing you where the costs lie in terms of buildability, working closely with your Architect, guiding them and encouraging design discussions.. unless you want to lose money.

This is interesting from a design perspective. I clocked this as it's a good span in ICF.. and then we have a steel beam. My thought process is roughly as follows: ICF is basically an insulated reinforced concrete wall with insulation. Reinforced concrete, if you have a decent height of concrete over an opening can be really efficient structurally. The wall can't be too thin but say it's "normal" 150mm. We don't know what the loads are from above but the 457 deep beam is likely designed for deflection (critical design condition) rather than strength. So the SE has introduced steel. But I then think as designer.. what about fire protection, insulation detailing, cold bridging, insulation fixing to the steels, differential movement between the materials and impact on the external and internal finishes and buildability. All that is going to add to the cost. This is where you really need to think things through. Scenario.. often the SE, (after Grenfell) will pass the fire protection to the Architectural Designer and then they will put some random note on the drawing for the ICF folk to make it work and they will pass it on to you as the Client.. you see the problem? My gut feeling is to understand why you need steels. If you have a two story building then sometimes we can hang the beam over the door from the ICF wall above, even if there is a modest window above. If only single story then is ICF the right solution? And 8.4 m door is going to be big bucks so head deflections are critical. To finish. Your design team need to get together and say.. this is a big area of moving glass so let's start to talk to each other and produce a well thought out design. For the technical minded: On concrete buildings we can use a principle called a Vierendeel girder where we look at the whole wall say on a two story building. This is where ICF has advantages over say a timber frame. If it all looks good SE wise you then need to make sure someone can built it and ideally save money. Again the SE stuff for the steel is probably straight forward but the detailing is where is could all fall to bits. ICF is simple in this respect.

Ok in the round you can look at this in a few ways. But one is that the planning and building control function subsidises other public services. A BC officer told me that BC make a profit but that gets "hived off" to pay for other "stuff" that you may not have voted for at your last council election. To be fair, if you are going to pull folks trousers down you need to tell them what needs to happen to be able to pull the pants back up. But they don't even bother to tell you that.

Hi Steamy. I've written a PM to you but can see you have PM's turned off. Can you PM me with your contact details? Gus

Much of this is above my pay grade.. but as an SE I can report the following: I'm using it as a tool to give me prompts in SE design. Prompts can be; suggestions and links to research papers, design code links and so on. This saves time thinking.. I have this info but can't find it in my large library of info. I always check the facts. I tested AI against some basic beam design, then pushed it a bit, chucked in some geotechnics.. which is a dark art. Again it served up a template that a student SE would get taught at uni. But it fell short of what is required of an SE which is the "art and craft of design".. but it still saved some time. I then thought I wonder is AI will write me some VB code (not just macros) that lies behind some of my excel spreadsheets and it made short work of that. If I have the will to live I'll ask it to write the VB code in excel that does a structural stiffness matrix which includes deflection. I wrote this a while back in excel for myself so I could check commercial SE software. I other words.. write me a basic frame analysis package in excel. Now you have a free basic SE frame analysis package! My better half is using and pushing AI a lot in complex areas and getting good results. For me, if you look at Grok it seems to be doubling in power every 4 to six months. That said, I feel AI is milking me for my craft so am wary that when I go off piste as an SE I'm in no hurry to give away my secrets avbout how you actually execute the art and craft of design.

Welcome to Buildhub and well done for posting a great question. What you have is a little different. Is your house circa 1950 to 1967? Here, after the war there was a drive for "non traditional construction" and the house builders were experimenting with leaner design. Conner, good spot! Agree with Conner in that this tie could be holding the external wall head in place and the toothing is there primarily to turn the internal wall into what we call a shear or racking wall. I can't say much more at the moment but if you want post a photo of your external elevation and put a line on it where you want to take the wall down that would generate more comments that might help you. Also changing the size of the opening in the external wall will lickely have a marked effect on the wall stability.

I think it's debatable. Both a low or tall radiator will still set up similar convection currents in the room. My own view is that the position of the radiator is more important and in a principle room appearance and position of the furniture will often lead to a compromise. Ok for a bit of fun to size a heating radiator system in the old days (35 years ago) when I was a building contractor .. still can apply when at the ball park quote stage. To get the customer interested I used to take them round the house and say... Imagine you had a one bar electric fire in this room ( 1.0 kW) or a two or three bar fire (3.0 kW) working on and off. Think of your Grans house. In this day and age we can use the equivalent of a fan heater. Most folk can relate to this. You run round the big rooms and as you go you say.. hey big window here and a draughty door say in a big hallway. You want to be able to make this room nice and hot if feeling like a duvet day? Now you add that up and with a bit of experience you can feel for the size of heating system you need. As an SE I use rules of thumb to size floor joists and steels and this is no different. OK so you now have a well insulated modern house. Take the above preliminary size and half it as condensing boilers work better at lower return temperatures.

Go for somewhere in between. Think maintenence and roof penetrations. Where you have eaves you need to think about roof access (and gutter damage) , something solidish to stand on. Verges, keep away from them as any disruption here can cause the roof to leak. Think about what service penetrations you might want in the roof. This could be a soil vent stack, any fan vents and so on. Keep a good margin around thec penetration flashings. If using tiles then think about the tile width so you don't end up with a funny width of tile.. the detailing is going to be hard and it gets harder when you have fewer tiles between the panles and the verges as there is less room for adjustment on the width as you lay them. Be careful folks as if you have not thought through the detailing and maintenence cost (risk of breaking things when you go on the roof) then it will come back to bite you. Remember that your house will not go up perfectly plumb as it will get built to a tolerance.

Local topography can vary a lot. On my self build, Qouthquan, near Biggar we had Tinto hill and the upper part of the clyde valley that would move the "local" weather about. Yes, you will get a lot of different weather, four seasons in one day. You will no doubt be appreciating how dynamic the weather is at your house, but one thing... it's not boring! Parts of the south do seem to be suffering from a long term decline in the main aquire level. That said it could just be that the performance of the borehole has dropped off, got clogged. Some boreholes don't last forever and that I suppose has to be factored into the long term (maintenence) cost when buying a house with a borehole.

It's interesting. I hope I'm not identifying Kelvin's site but I've been there. About a mile or so down the road is a farm that I have a family connection to. This used to be a highly productive soft fruit farm and if you wander about you can still see the bases of the prefabs that armies of berry pickers would come to every year. The key thing is that this farm sits in the rain shaddow of the mountains but also the geography then further splits the weather and that doesn't get picked up even in the local weather forcasts. Go five miles further up the road and I think you would get a different output from your PV.

But some clear braided hose pipe 19 mm diameter. Set two stakes at each end of your slab and purge with the garden hose. Get some drain dye and fill a canister. Tape a funnel to one end of the hose and pour in the dyed water until it comes out the other end. Don't use too much dye just enough to let you see some colour. Now you have a water level. To give you confidence mark the bottom of the miniscus on the stake. Then with a helper (easier) swap the ends of the tube and if you don't get exactly the same reading then you have air in the pipe. You can move one end of the pipe anywhere you want as it will maintain the datum level. To do this you can make out of timber a tripod so the water doesn't spill out the tube. Once finished stopper up the pipe so next time you want to use it the set up time is less. And once finished the build it reverts to a garden hose.

Nice to get a surprise like that when something performs better than you expect. Well done!

I sometimes specify Farkro on my drawings or Velux or equivalent. One thing to keep at the back of your mind is trickle ventilation if opting for the traditional route rather than a mechanical ventilation system or the like.

Missunderstood so appologise. I think @saveasteading has a generous plot but if building on a quarter of an acre you can't go ground mounted. My Mum kept bees in Perthshire, hive orientation is one key aspect. Is your cliff not north east facing? The bees will freeze in the winter? Likewise if the hive get too much direct summer sun then the bees struggle to keep the hive cool. Ta. As a desinger I have to consider fire. In the old days we would have a petrol or diesel car in an intergal garage and we would design for that going on fire. But now we have EV's that are a different risk in that the development of a fire is different. A big solar battery contains lots of energy but is maybe not subject to the same level of safety scrutiny as a car. So why have that in your house if you can avoid it. Sometimes we can tailor the landscaping to compliment the modern solar panel. In Scotland on a banking we will select heather plants that change colour and flower at different times of the year. You can contrast this with the stark canvas of solar panels, you are not trying to hide the panels rather, you state.. here is a mix of old and modern.

That looks a tidy job but what's underneath which is what we would like to know!

In the grand scheme of things a difference of 2.0k is neither here nor there when you consider maintenance, replacement cost with a system that might not be compatible with your roof makeup and the fundamental design choice of ground or roof mounted. The way we mount solar panles on roof has changes a lot just in the last few years so expect this to continue. There is discussion around net zero and we can see good farmland getting build over. Ask, why are we not covering industrial buildings in PV right next to the point of demand.. it's down to cost and ongoing maintenance. So for self builders if you have space then just follow the ground mounted route.

To add a bit. The framework for ground mounted solar panels is often galvanised steel cee sections, similar to what you seen on motorway barriers. These are designed to last about 25 years, if in the country you just need a local fencing contractor to knock these into the ground for you. They are used to getting fences straight so not a challenge in this respect.

Ok let's say you have a big plot and in that case I would say if you want to get there, don't start from here! Consider a ground mounted system even if to rule out. There are significant advantages of ground mounted. You can optimise the orientation of the panels. In the years to come as they start to fail you can replace easily in stages from ground level. If you need a soakaway for say your sewage plant then put that under the solar field if possible as the panels will restrict plant growth that could clog the soak away. Every time you add something to a roof it requires flashings and details.. all that is extra maintenence and cost. Think forever home and resale value if you need to move out. Well from my experience they used to be. When I worked as a designer for a cold formed steel shed business ( the biggest by far in the UK, we did at least 700 to 800 sheds a year) the feed in tarrif was exceptional. The company I worked for sold a deal to farmers whereby their shed came free but they had to agree to put a 40kW solar system on the roof. During that time they were responsible for maintenance and after 25 years they got to keep the lot. It was a great deal but the folk that were supplying the invertors were cowboys and two buildings went on fire and one from memory killed valuable animals inside.. the word got about on say the Farming Forum and the game was a bogey. So yes, there is still a fire risk but why take any risk if you don't need to? Best to keep the invertor and so on outwith the building envelope if you can. For all on BH if you have ground available then use it for a solar field. Think maintenance. Say you have a two story house and someone needs to go up and clear the drainage around the roof and panels and give the panels a wash. Two men half a day = £400 quid plus a cherry picker.. call it £ 800 -1000.00 a visit. But if ground mounted you can give you solar panels a quick wash when you are mowing the grass. Even if you do a quick sum you can see that long term the maintenence is a key issue. If you split the difference you can then maybe buy the best performing panels and best quality currently on the market and still be quids in on ground mounted once you consider the maintenance cost. Like this analogy. @saveasteading I've made some points. Good design is often about ruling things out rather than in as this allows you to focus on the things that you really are going to build. This is where Build Hub excels as it let's members float and discuss their ideas at a really basic concept design stage without any real pressure or getting slagged off and dismissed.

I was talking to a Client about this the other day about the difference between a geodetic survey and a plan survey that we might do on a small site. But @steamy love your post as for high accuracy we need to decide if this is material. Case in point could be if we want to monitor settlement in a sensitive location. For all if you get a professional surveyor in with modern equipment there is a button you press that does all this complicated maths in the software with a bit of manual input on the curent weather conditions.

So if you go over the score and blow the transformer up.. you'll get a bill for it but the chances are no one will get hurt, you won't cut off the old folks home down the road and so on. Incedentally animals are very aware of electircity, that's why cows lie down in a thunderstorm.

Something to look forward to. Just to be pedantic I'm assuming that your neighbour is one of the six houses served by the private treatment works. If that is the case then we can rephrase the question and direct this to the Thames Water. A public sewer is a Thames Water asset, so you need a buildover agreement to build over their infrastructure. If this is one of their assets then they have adopted that including the treatment plant and should be maintaining that at their expense. Ask them if this is a reasonable statement of fact and invite them to confirm. What may be the case is that you have a private agreement with the other home owners to share maintenence and upkeep of the shared private sewage system. You have a duty not to do something that will cost your neighbours extra money if there is a failure of the drainage system, say if your extension is badly built. If you want to build over then its your title deeds to look at and you may require your neighbours consent rather than Thames Water. Now it's a bit late in the day for this so if push comes to shove you may be able to take out for example an indemnity policy or just build it properly so you never have a problem. Now generally if the drain is outwith your founds then it's fairly simple, if within the foot print then you need to take extra care before you get the build underway.

Good approach, let pragmatism prevail and march on!

@Roger440 threads are overlapping you beat me too it!.

There are ten pages to this thread Roger. Can you describe what is upstream of your connection? Don't forget that nothing with the leccy board is transparent and often is driven by some accountant rather than engineering knowledge. In some ways it's worth trying to see it from the leccy boards point and how diversity works at their end. If you can put yourself in their shoes and "see it" the way they do then you'll be in a stronger postition as that will let you get past the admin / accountant and talk to one of their engineers who will probably sort this out in half an hour for you.