Gus Potter

Great points form all. For all. In the past often we wanted to make sure that a pile could carry the design load. Say you have ten / fifteen piles then the SE / Geotech Engineers may come to site an pick one or two at random for testing. The static load test basically involves bringing a lot of kentlege (heavy weights) to the site and making a cradle spanning over the head of the pile. You then put a big jack between the pile head and cradle and pump it up while measuring how much the pile sinks by and the time it takes to sink by a certain amount. This a bit like the CBR test that you see mentioned for your access / drive or hard standing... but more complex as the risk is higher. This static testing takes a lot of time to set up hence the cost. You need space and there is a cost to; bring the kentledge to site, build the cradle and make sure folk don't get sqaushed! One other (not least) problem is that you have to calculate the probability that you have not just picked the two best piles! Now with modern calibrated piling rigs and computer analysis the piling contractor can gather a lot of info on say a driven pile capacity as they are knocking it in. A concrete pile say is a bit like a tuning fork so you can measure the frequency of the vibration as the hammer hits the pile and how much it is driven in by each time this happens. You then compare this with a known data base of responses. You can even let the pile rest for a while and go back and give it another few taps with the piling rig as some piles behave a little differently once the soil / water pore pressures stabalise from the intitial intrusion of the pile. A bit like bread or reheating a curry the next day.. piles can be better or worse after a few days! Good point Mr Punter. Concrete piles can shatter under the ground. They may take a static load test too. One thing about a static load test on a pile that you are going to use is that you often only test it to the working load or a little more. If you test it right up to the point of destruction then you now have a useless pile and that poses a problem. Often a dynamic test will identify piles that have shattered as the frequency response is different (burst tuning fork) still a problem but at least you know and can do something about before you construct a building on top. The ODEX pile is pretty cool but simplistically is a big drill bit with a large say Bocsh type SDS drill on to top but a lot more expensive.. not available at Screwfix. As the hole is drilled it's cased with a steel tube to stop the sides of the drill hole from falling in. In say parts Glasgow (off the top of my head I can't name locations in the rest of the UK.. any input from BH folk welcome) there is a certain type of boulder clay that contains boulders the size of cars / houses. Surrounding these is often a very soft material. In a BH context for low rise domestic housing this is not often a major issue, provided your pile is not scuffing the side of the boulder, load it up and the end will be stressed just like when you break a drill bit hitting a nail in a bit of wood. The ODEX pile concept (not new though! ) is also good for when you have say cavities in the ground like mine workings or a layer of fine sand / silt that washes into the bore. To kind of finish this. You can see on the BH resource that it's really hard to get a handle on the cost of piling. However, hopefully you can see why the cost of dynamic testing is less than the static load test appoach in cases applicable to what we are doing on BH.. much depends on the type of pile you have though. A screw pile is a different animal and needs a different approach for example. Again for all. As a starting out BH member looking at piling. For me the first step is to look at what you need the piles to do. Do you just need them to carry vertical load or do you need them to carry sideways loading too. Sideways loading can occur for example when: 1/ Your house is elevated off the ground and thus the piles need to act a bit like a cantilever to resist the wind load. 2/ You have an elevated house due to flood risk.. near a river where you want the flood water to be able to flow under the house. Here you have to take into account scouring of the ground around the pile, getting hit by floating tree trunks etc, the sidways loading of the water on the pile.. 3/ You are building on a slope with a soft layer of clay that could slip and impose sideways loading on the piles. If piles need designed for horizontal loading then the cost can jump significantly. For piles that only need to carry vertical load then often much easier on the budget. The key here is to spend money on a good site investigation. For example trial pits, window sampling, shell and auger rig, boring if need be. This gives you the raw data. In terms of reporting there are two "halves" to a soil report. An investigation report.. this has the data that was logged and that is it. The other half is what is called the interpretive report. Here say the Geotech Enginneer will tell you what kind of piles will be suitable, how big / long they may likely need to be, alert you to potential ground contamination and so on. An interpretive report carries a lot more liability so expect to pay a good bit more. On the other hand expect to save money when going to tender. In the round you'll probably come out quids in and you will reduce you financial risk! Just you'll need to stump up early doors... which most folk are reluctant to do as often folk think site investigation is just like council tax. Hope this helps.

Spot on. What turns my rose tinted specs to blood red is when you get radio silence.. what you seem often to get now is an automated response. The last one I got was.. we acknowledge you have paid us money, your BC officer is xyz and they will be in touch in due course. If they recognised that if they dropped you a quick note to say... Your submission is on my desk. I'm really busy due to abc but won't forget about you. After all it could be their old mum and dad that are needing to get the work done. If they did this then they could avoid many of the phone calls / emails from folk just wanting to know what is going on. It's not professional to just ignore folk. They could even say, thank you for your comprehensive and clear submission...please give us time to study it in detail. Believe it or not sometimes you do get a verbal compliment from BC / the Council Engineers on the quality of your submission. I agree with the Sole's approach, achieving a high standard.. that is the mark of a professional and in some ways it's encumbant on BC to step up to the plate.

Hello @saveasteading For the avoidance of doubt I was responding to the r_sole as the sole was pondering whether I had had been on the Scottish Building Standards joy mobile on a regular basis. "Some were over tough, esp London ones, who still wanted to use their old manuals and hated Eurocodes. Big arguments with them, but the full volume of building regs on the table was enough to make my point. A checking Engineer even said he didn't like Eurocodes and could we redesign a whole shed to BS. NO." For all. It is still perfectly acceptable to design to the British Standards, there is no requirement to design to the Eurocodes in most cases in the UK for BC purposes. In fact there are a number of areas that the Eurocodes don't cover in a UK environment. There are a couple of caveats positive and negative.. for you as a home owner/ self builder. On the negative side you can still design to the British Standards so long as you know where the BS has been proved to not meet the current accepted research knowledge embodied in the Euroodes. For example take a steel portal frame. The BS requires no explicit check on whether the haunch should be stiffend or not at the sharp end. The Eurocode does. For all.. that seems like a pedantic technicality but BC will pick up on that.. well they should. You can still design a portal frame to the BS but include the extra haunch check. More importantly for the typical BH member is this. The Eurocodes allow the suppliers of certain products to say hey our stuff won't fall down but as we are using the Eurocodes it is up to you to agree with your designer what deflections are acceptable. In other words you could as a lay person buy a product designed to the Eurocodes that is going to crack your brickwork unless you have the technical knowledge or an SE to say.. hang on, lets look at the deflection. The British Standards often have enough clauses to protect say the BH member. "Which brings me back to the point. I think Sole you are saying that they will always ask questions because that is their job. therefore don't worry about the perfect application, as they will still ask questions, perhaps with invented problems. " Yes agree, BC's job is to guard public safety. Sometimes they will ask some apparently odd questions. Sometimes an inexperienced BC officer (us too on Bh) will ask some daft questions or not even know what they want to ask..they just blurt it out. It happens.. there is often a way of smoothing things over. What a lot of folk forget / just don't know is that you may live in the house for five years and never load up the floors say. You sell it and a young family move in and stack it up. The house is designed for a 50 - 60 year occupancy. Yes, you may think it 's your house, you bought and paid for it but that's not the way it works in terms of public safety! It's hard to get your head round it and often this is one reason why folk wonder why they are in conflict with BC.

I'm going to stay up all night to monitor the feed back on this one! Starting off sensible. Take the small burner on a gas hob. Say with an output of 1.0kW and imagine you put a very big pot of stock on to simmer overnight. You use say 12 kW. Multiply by 2 for 24 hours = 24 kW. Now run that for a month 24 * 30 = 720 kWh.. Now a hot tub.. and they are not insulated to a passive house standard is a bit bigger than a pot of stock. Unless you are both very small people about the size of an action man / woman. Yes I know the hot tub is not simmering but it has a much larger volume and exposed surface area. It's probably got nothing to do with the ASHP.. is he winding you up!

Fantasic.. you've nailed it... traffic lights are show red for a reason.

Yes, not been there Onoff but worked on the redevelopment of the Westcott site at Aylesbury. Was mitigated by the fact that the building was for a formula racing company so was able to design Architecturally / Structurally to fit with modern technology, slick, fine lightweight look.. did it in cold formed steel with lots of small bolts so the building reflected the look of the racing cars and porsches. great fun. I'll give them a plug.. TopCats Racing, just checked they are still in business! . Always at the back of my mind was the history of the site.. British invention... the best! Westcott was used as an air field for the Blenhiem Bombers in the war, then was adapted to develop the rocket fuels when the UK was developing our own nuclear deterrent. I really got into the site investigation uncovering the history of the site, they were pumping some funny stuff into the drinking water aquifer!

My Dad also told me to always touch something with your right hand first even if you think it is isolated. Mind you if it's a pylon then it's just a question of which side of you is rare, the middle well done and the rest a dusting of fine ash? Do they teach this still to sparks.. When did the United Kingdom start going wrong? When we started to loose our common sense.

Never thought of that but on Build hub every day is a scool day! Will go and read the leccy meter now. If I turn that upside down will I save energy?

What an insult. I'm left handed! When doing DIY electrics I just turn the sockets upside down so the earth pin is closest to the skirting, that sorts any polarity issues. Please always seek professional advice before following mine.

Reminds me of my Dad and one of his early warnings about the dangers of electricity. Electric wires, boy pliers, blue flashes.. boy ashes! He spent some time working on radar and had a few "electric thrills" in his time.

Welcome Buildabear. Well done you for taking this on. I hope you find the following info helpful and that it will give you some pointers as to what you may want to consider. Firstly and again well done..you have identifed that the 3x 3 post is splitting the span of the purlin. If the purlin is continuous between the masonry walls it will be attracting a bit more load than you would expect. Story for another day but the post will often be carrying more than 50% of the roof load if the purlin is continuous. Your starting point here is to have a look at the wall you are taking away and what it is doing. Is it just carrying some vertical load or is it also providing sideways (lateral stability to another wall? Often walls perform both functions. In the top photo you can see that the wall has been toothed / bonded into the external wall pretty well and to the right hand side there is a window. I'm guessing but is there a window to the left we can't see? If so when you take the wall away you'll be left with a bit of masonry between the two windows which now becomes a column that has significantly reduced lateral support between the floors and ceiling. Often you find that the column can cut the mustard when subject to a bit of wind load. Now lots of folk will say.. don't be so dramatic..! as we have done the same or seen other houses that have had this kind of alteration say 30-40 years ago and they have not fallen down. But back then you maybe had good solid timber windows or metal framed windows. This framing often added enough strength to maintain the stability and strength of the wall. But over time these were stripped out and replaced with plastic windows and pretty rubbish brackets so the old rules no longer apply. For the curious there is a bit in the BS design codes that touch on this swapping solid framed windows for more flexible frames. It would be worth having a chat with an SE to see if the things I highlight are relevant before you commit to much or take down more of the wall. It may be that all is fine but if you can get some confirmation from say an SE it could ease the way not least when you come to sell in case a surveyor takes the same analysis (ask questions) approach as I have outlined above. Do this and it may allow you to progress with confidence in the knowledge that you are definitly improving the value of your home with much less risk? All the best with the project and keep us posted on your progress. Oh, and don't forget to put up a photo of the finished article.

Not died yet! But like death and taxes.. both are inevitable and we have plenty hills in Scotland. Some this quote can be attributed to Frankin, others say Mark Twain but Christopher Bullock (1716) seems to be the front runner? According to the Adam Smith Institute. "I'd guess going by your comments that you havebn't dealt with a lot of building standards officers in Scotland!?" Mixed experiences here. Having been a contractor / designer working in Scotland for the last 35 years I've "interacted" with the odd one or two.. but remain hopeful..as many more rather than less are helpful in my experience. I'm now also a bit deaf and wear thick glasses with a rose tint so that helps too! "Young forward thinkers are only a couple of applications away from being jaded!" I think you sum this up well, bit of a sad situation though, can't be much fun for them either. What I have found is that there is a bit difference in approach between the different Councils, I think you expanded on this a while ago Sole. For all, this can be a consideration in how you couch an application so in some ways Sole I agree with your approach. There is a bit of a churn in staff going on in some of the councils with folk leaving and them finding it difficult to recruit and train new BC officers up. Argyll and Bute don't get a nomination from me as the best Building Standards forward thinkers of the year. This year my Central / West of Scotland nomination (so far) would go to Glasgow or North Lanarkshire. The year before South Lanarkshire.. but not Perth Council.. I tend to stay away from the east coast and up north.. as plenty to do locally, good to holiday there though. but there are a few folk on BH that can maybe add their nominations?

In fairness to the builder they may have a point just not communicated the concept very well. Also, they may not have a full grasp of all of the issues such as continuity of the insulation envelope and so on. "We have a section of stone wall to replace, and had drawn a cavity block wall onto which would go external cladding." The first question is how big is the section? A few metres or a lot? and how does it interface with the existing stone walls? If it's a short section then I would look to see if there is any merit in rebuilding it in natural recycled stone from the site to match the existing using the same mix of mortar (or as close as you can). Here you can mitigate the effects of shrinkage and avoid the difficulty of trying to bond a cavity wall to a solid stone wall.. this can be time consuming to get right. if the existing walls are a bit loose then you find you keep having to remove more and more until you can make a good bond (tooth) between the new and existing... If you use concrete blocks then they do move about differently from any existing stone walls. It may be that you can take this approach and move the external "rain screen" to another location if it intended to be a feature? "So they propose a single skin, thick block, structural wall. Small gap then stud and insulation inside, the same as we are gong to do to the stone walls, and clad outside as planned." How thick is the single skin to be? 100mm, 215mm (block on the flat) or more? "Any comments to confirm or deny this is the local way.?" It might be for small infill areas but these days we tend not to go for solid wall construction as a first option, unless it is retaining something or is on say an onerous fire boundary.

What happened to the Aberdeenshire project? I was rooting for you on that one. Now you're onto sand and granite.. help ma boab. Ok before you get carried away on drainage you need to look very carefully at where you are.. have you trucked over to the West Coast or moved a bit further into the Grampians? Quite a few of these sites (Islands & Grampians) have granite dykes with sand inclusions.. expensive if you don't know your way round the houses..a lot of the easy sites have been snapped up years ago. "I take it you know of glacial deposits that are stickier, but working with ground made of sand it is a new material to me." Yes I have a working knowledge but every day is a school day. "Yes, I learned about puddling re canal projects in the Midlands." Me too, cut my teeth on a project in the Midlands where a young couple had a canal boat building business and expanded to make a marina with a bit where folk could moor up all year round and live on thier barges. the marina bit had a lock and needed lined with clay.. happy memories! If you fancy post some stuff on your new site..to get best feedback you probably want to be a bit more site specific.. For all.. I think this is a great place to learn and exchange ideas but the folk that run it need some encouragement. That could be just a quick thanks to the mods or maybe a small contribution towards the cost of running this site? I'm more than happy to chip in with my contribution as I enjoy sharing what I know and learning from other members.

Good stuff. Do a good friendly informative report, you have the experience, take your contractors hat off and hold their hand, make it as easy for them as you can to check if they want. Yes, reference the proposed treatment plant. One key here is to make sure you say the plant is CE approved in the main body of the report..some tanks are still not CE marked so you can get caught out here.. leads back to the the Eurocodes which the Scottish Building Standard reference. The simple way is just to copy the manufactures data sheet and drawings as an appendix to your report. Then say " or similar and apporved" as this lets you select a different tank later if need be. Don't go over the score with the technical drawings.. better to include a few with your own reasoned analysis of how the tank will be installed on your site. Touch on the water table, potential flotation when getting emptied, the runs on the pipes to the tank, how you will empty it, the sampling chamber, DON'T forget to specify the manhole cover! light duty or heavy duty! It all sounds like a lot of work but you'll need to produce the same info for the builder, add a few notes and change the title box. You'll most likely sail through this but wrong spec for the cover and you are totally stuffed! Oh and are you leaning towards the pond idea yet?

Hello Old Kettle. In the spirit of BH and.. the planners.. we are all well intentioned folk. Totally agree we all need to live next to one another. To work this out you need to start from the outside plane of the roof and work back. It's generally accepted that the eaves height for PD is this. Project a line from the outside face of the wall up to the top side of say the roof tiles or roofing felt. This is the eaves height. The folk that drafted this are not daft! The wicked may add a lean to log store onto the side of their building. Here they (the wicked) would argue that the footprint of the walls complies with PD but the eaves height is say the facia level of the log store. The result would be that you could have a pretty high structure right next to your neighbours. Not very fair as they could do the same to you! The next thing is that the eaves height is normally measured from the natural lowest point of the ground adjacent to the proposed walls. Thus, if you have sloping ground it's measured from the lowest point of the established natural gound level. This to is reasonably well drafted. You get some folk that will "build up their garden" by adding decking or planters and measure from there. For the "enthusiastic reader of the PD rules" better to take your chances at William Hill. The planners have seen it all and now with google and all the histroric photos? Now you can dig down as what we are considering here is the impact it will have on your neighbours. If you sit the floor say 1.0 m below the existing natural ground level then the height for PD is still taken as that from the natural gound level. With a bit of thought you can probably get what you desire. If you are digging into the slope then you need to put a bit of thought into the SE / Geotechniques design as you are into maybe retaining wall terratory / damp proofing, maybe party wall stuff if not in Scotland. It's all a bit back to front but once you get your outside envelope established then you can work back without having to reappraise. Old kettle hope this helps.

You're doing a one off project in a fantastic part of the UK. Why put a big plastic tank in the ground! For me it sounds bonkers to put a plastic tank in the ground in Aberdeenshire just to comply with some fire reg. Save a Steading.. if you drive about you'll probably find that there are a few farms further up the hill that have clay and want rid of it or will deliver a few loads. Also, if you have loads of sand and gravel then a bit of clay introduced to the garden with the clay minerals associated will improve the soil.. all you need then is a few trailer loads of dung and hey ho..the cost of the pond will be mitigated! Remember that Aberdeenshire is in the rain shaddow of the Grampians and can get pretty dry. If this is the forever home then these things matter. Dig a pond and line it with clay! For all.. London clay was used to line dams! A well battered Scottish Glacial till will also suffice, it just needs to be a bit thicker. Oh, and once you get the Mallard ducks visiting they will do all lot of the maintenece and take care of the midge larve. For me if you have grandkids / kids then having your own pond allows you hang out with them, you can do the nature stuff but also teach then about water safety, what not to do and what you can do. When you can walk on ice and when you can't. Hey if the pond is big enough in Aberdeenshire you may be able to skate on it in the winter! Fish for tadpoles, what to feed the wild ducks... Mallards will nest in a duck house too on a small pond so long as they feel the foxes can't get to the nest. @the_r_sole "I would always rather put in the perfect application and get straight approval, but am wary of officials always wanting to show their authority by asking for more. " 'Sole.. that could be construed as just a box ticking excercise. Having read your posts I don't think that reflects the many years you have spent learning your craft and technical skills. I note you say you would prefer. Yes, there is alway the risk that we may encounter officialdom, it's something I wrestle with too.. do you design to just comply or do you challenge / stick to your design intent? Much depends on the Client.. but if you can say.. for all .. hey folks this is going to add value to your house.. no one else has this but do you want your dream home or do you want what YOU want.. Architecturally designed by the Sole say as a one off just for you.. what about putting the new Audi on hold for another year and spend your money on something that is going to deliver much more long term satisfaction and value. You can be cynical, chuck in a howler on your application with the full knowledge of your Client that the Authority will spot it and that you can compromise on, but still keep the design intent.. for me best just to stick to your guns and play it off a straight bat. What has happened to the system where we are even discussing compromising just to get approvals? Why can't designers / experienced builders / contractors use first principles to innovate? I think we can.. but we need to find a new way of communicating our ideas in a positive way that encourages the young folk that are on the Authority side to engage.

cyber attack! Yes they took a sore one on that but think they have recovered to most extent, but still feeling a bit wounded! Sole.. concur with the rest.

In the current climate I would do a good report.. Reports are often intended for a target audience as we know. Put together a report on your soakaway tests. I would aim for about 15 -20 pages. Include a site plan, an arial photo if you have one, introduction / conclusion to your scheme. Identify the objective.. tell them what you are going to tell them! Reference the head documents. BRE 365 for your rain water, septic tank percolation tests to say recommendations as per SEPA Regulatory method WAT-RM-04 for the septic tank for example.. the wee 300mm holes. Describe a bit of the local geology. Surface deposits and bed rock. You can find info here on this https://mapapps.bgs.ac.uk/geologyofbritain/home.html for your accademic research. Don't include a highly technical description of the soil, just say for example, river / glacial? deposits comprising SAND and gravel, or GRAVEL and sand. Then say what this means. For all the word in capitals mean that the soil is more composed of SAND. Don't lay it on thick just explain the reasons for the capital letters. Show dimensions to water courses and how the soakaway complies with boundary distance and proximity to the dwelling. If you have the will show a cross section of the ground. This can be helpfull. Put a note on the drawing saying for example X dimension complies with Y recommendation or clause 1.2.3. For all BH folk..if you have sloping ground what can happen is that rather than the water seeping into the ground and "going away" it just runs under the surface and appears as an unwanted spring further down the hill. Next for both surface water and spetic tanks tests and calcs. Plenty photos.. make sure you state the weather conditions leading up to the test and during. It is not unkown for folk to test at the end of a dry spell to get stuff over the line! Make sure the photos show virgin ground.. again it's not unkown for folk to cheat. BC know this and are wary of folk doing their own DIY porosity tests. Often I'll do an extra hole or two if I can if time permits. If you have good draining ground show that it is.. this can head any queries off at the pass. Now for the experienced you may wonder why I'm stating the obvious. At the moment some councils are in a bind, some less so but they are all struggling. For example one council I have dealt recently took nearly 8 weeks just to consider the information in the warrant application. I wrote to them and asked "how are you getting on" Got a very pleasant phone call from the senior BC officer saying.. we are a small council, half our staff have left and we are trying to recruit. Another council processed a warrant application faster than normal! It's worth producing a report that leads say a new BC recruit by the hand, write to give them confidence, give them pointers (SAND and gravel for example). They want to learn.. make your submission attractive, readable and friendly. For all the crusty BH members. Imagine it was one of your kids in a new job trying to learn the ropes. A good report should tell a storey and lead the reader..yes you can write a dry report, challenging and try an impress / bully with technical knowledge.. @saveasteading I would stick my soakaway report in with your warrant application. You won't get your completion certificate and probably your warrant until SEPA give you the OK. Best to get all this out the way early. In Scotland there is less of a worry about overloading BC with info, we don't have arms length BC or private BC in Scotland. But don't send them rubbish as this will hack them off. Having read your posts it looks like you have a very interesting project ahead of you. In an ideal world you may want to set this up so the Senior BC officer will feel comfortable sending a young trainee / or someone (older person) that is retraining to your site in the knowledge that you are not going to chew their head off. As you have a pile of experience you could build a good rappore with the BC officer going forward.. every one is a winner! Try and call SEPA and log the call.. but last time I called..they pretty much fobbed me off. I think it was because they are working from home and just can't shout over the office for advice from the seniors.

Yes you can mix and match. Yes there is a metal substitute for timber joists.. see Steadmans / Albion Sections for cold formed steel joists etc. You'll find these expensive as anything you buy will be a small order. Often you have to be more wary of condensation / humidity which does not fit well with musical instruments / sound production! Best to post some photos of what you have and a description of what you really want to do to get best feedback from BH. Sounds like an interesting thing with the added challenge of a limited budget.

The simple way, as you'll be needing a decent found for the two storey extension is to cast a small strip of found to extend the existing house found assuming it is strip found you have and not ground beams on piles say. Other things to just be wary of is things like ground gas.. does your house have measures to contend with this and the like? You can dowel this into the existing so long (good practice at least) as it appears to be just supporting the ground floor load. The foundation extension supports the new beam and block floor which can cantilever by up to say 75% of the beam depth to be safe if carrying a domestic floor load only. If you know what you want then find an SE who also knows a bit about design (they will give you free tips) and getting stuff through building regs. They do exist! A good experienced SE will have spent many years working with Architects, good experienced Architects have spent many years working with SE's... it's a two way street! In other words a good Architect can size up stuff structurally and not often be wrong! it's just that doing calcs for BC is not often their thing! Both if experienced will be well versed in how to do energy perfomance calcs, drainage design etc. Same applies to Building Surveyors, there are a few that are well rounded. I would shop about if you know what you want then you may be best with the SE / Surveyor route as you'll maybe get more "construction" information?

A pragmatic view from me..? Having built a few houses out in the sticks and lived in the sticks the last thing you want is for you house to completely burn down due to a lack of water if a fire occurs. Have experienced a neighbours hay lorry going on fire next to their house, used loads of water to stop it setting light to their house. The fire engine ran dry and we drew water from the ponds. If you have the room then ponds can be great fun, not just for kids to learn about nature but for adults too! Once you start to play with them.. it's addictive. If you have a descent roof area you can fill them pretty much with the roof and surface run off water. I can see the logic from my own experience about having a 45m^3 storage as but that is not a big pond. If you live up in say Aberdeenshire it gets pretty cold. If you are doing a pond then you want the aqua culture to thrive and not freeze in the winter. You can find plenty stuff in the SUDS manual about this but in essence you have a shallow sloping bit and a deep bit (1.5 - 2.0m) for winter conditions, lower light levels and so on. A pond of say 6 * 8 *average 1.0m deep will give you your 45m^3. It will vary a bit depending on evapouration so you need to do a few calcs. Yes if you are in sandy ground you'll have much loss so will need a plastic or clay liner. But all this needs to balanced against the fun you'll have playing about..the self build journey.. it's not all about the money you know!

And Great points, power to the elbow! The thing drew my attention to the stability was the aspect ratio of the structure. Height to windward length. In other words it is quite tall compared to it's footprint. There is also glass areas that would require some careful movement control not just in terms of vertical deflections but also horizontal deflections. Doing this in timber could be challenging when designing the connections to say the least! These types of TF connections need a lot of space which could destroy the Architectural intent. If you look at the the walls facing the wind in the east / west direction there are not many in the "right place" of a decent length (without some fancy modifications) to resist the wind loading in this direction. Now if we were to make the building footprint larger in the east / west direction but no taller it would be more "squat" when considering the east / west wind and probably have more internal walls we could use to brace. This would then concur with the order of your analysis. I agree that steel is not best suited to angles and curves.. in the round my feeling is that it is worth a close look at a steel frame on this project just to make sure you have not missed an opportunity. Beware modular timber suppliers quotng "excluding all steels". great advice from @saveasteading

@saveasteading You have hit the nail on the head here. You can use them as as part of the "treatment train" for water run off and pollution manangement as per the SUDS requirements. In lay terms. Green roofs can hold the water for a while during heavy rainfall and then release it slowly into the eventual water course.. helps mitigate flooding. Water evaporates too (when it stops raining locally) and so on so less ends up down steam.=adding to the flood volume. Also, during dry weather air pollutants settle and get trapped on the growing matter. If you have tin roof and a dry summer you get all sort's on the roof from bird droppings to particles from car exhausts. If you get a short sharp shower of rain this all ends up quickly in the river which probably has a low flow so the concentration of pollutant is high and it kills the fish for example. Green roofs can get you over the line for your permissions to build but saveasteading is right .. if you don't look after the roof, like you wash your windows or water your house plants it's all a load of.. guano / smoke and mirrors.

Hello Pipedream. Wow! No wonder you're happy! At first glance it may be worth looking carefully at whether this may be best build as a complete steel frame. The elephant in the room here is the global sideways stability of the building. On the ground floor you have a lot of glass, the building is U shaped, three storeys.. it will pick up a fair bit of wind load. I would get an SE to mull this over before you progress any further. Make sure you get the stability nutted out as you don't at first glance have enough walls in the right place to achieve it without some complex bracing systems and associated foundations to "ballast" it. This means money and a fair bit of it too! The above is not gloom and doom. You may find this is the most cost effective way. Steel is really versatile. For example you could look at a mixture of hot rolled steel beams ( the big I sections say) and cold rolled floor joists and roof members. They are often Cee shaped (zed shape on the roof) and thin walled.. just the same as you see in B&Q holding the cladding or an industrial mezzanine floor. Oh and you will probably easily carry any extra wieght of a green roof to boot. It requires a different approach (mind set) to the detailing in places.. cold bridging, insulation and fire protection but it's all doable. Cantilevers can often be more easily dealt with using steel, section depths are less and this allows you to more easily avoid "chunky" details and encourages more slender details for visual appearance. Really what you do is design an "industrial building" as the skeleton and over clad. The steel frame is just a meccano set, quick to erect. Also, many of the weather proofing details are already developed, you have less issues with shrinkage cf masonry and timber.. plenty positives. If you wish post more drawings. A good thing to do is put gridlines on the drawings if you can as it allows folk see at a glance how things line up between floors. Al the best with what looks like a great house.