Gus Potter

Yes I was expecting a huge hike in my PI as a sole practitioner. Couple of drivers were.. a lot of folk are not making a good job of basement and swimming pool design and the big thing is the cladding / fire. As a guide an SE sole practitioner can get £2.0 million cover for under 2.0k a year with 5 years no claims provided you stay clear of swimming pools, tricky basements (deep ones) and fill in the forms correctly regarding the maximum height of building you are tackling and where you lay off the liability in terms of cladding design. Now you probably don't need that level of cover if you avoid the SE side. I would hope that you could get PI for 1 -1.5 K maybe a bit less? for say 500 K cover given that your are a Chartered Architect. Now in reality to work on your own and starting out you generally need the bread and butter work. The garage conversions, extensions and the like. Commercially you spread the risk of getting hit with a dodgy Client that refuses to pay.. all your eggs are not in the one basket and you can afford to take a hit / fight it out while still making a wage. Do a good job and you'll find these bad clients are few and far between.. but get the odd bag egg who owes you a lot and it scunners you. You could go for the high value jobs and only need one or two a year.. but the cash flow.. getting used to working for your self, worrying about getting bumped.. Also if you only do a few jobs a year you don't get your name about that much. Remember that if you do a job for a young go ahead couple they will then often get the bug, move to a larger house and phone you while recommending you to their friends.. On the upside these small jobs can be very technically challenging.You can be highly creative as to how you design so it's not boring. These small jobs can be a real test of a designers skill. Once you get up and running, or now, try and seek out some young keen, intelligent, dilligent small local builders that have a future.. make yourself the go to Architect and as their business grows so will yours.

@CharlieKLP Good thread this and you are holding your own! I'm sure you will do well and enjoy your journey. On small jobs, say extensions and the like I don't provide the CAD files to a Client unless it's been agreed at the outset. I do though share my files with Architects and others that I know and trust not to do anything daft with them. They are shared as uncontrolled files and this arrangement works both ways. I often say when you let folk see the cad file it let's them see into your sole, it's you own personal work space. When making formal issue of a cad file I strip out any IP that is not associated with the job as yes you don't know where it will end up. But doing this when collaborating with folk you trust and have worked with is just sending out a message that you don't trust them! Yes you clean things up a bit so they can comprehend what they are seeing but often I splatter notes and my thoughts on the cad file so folk (and myself later ) can see what I'm thinking and where we need to go with the design. Once you get to a certain stage the design is frozen and so is the cad file. If issue is required. Food for thought. lets say you have a new build with lots of steel / industrial building. You have a set of pdf drawings but on larger jobs to give your Client a wide range of options you also provide a numerical control file called an NC file that the fabricator loads up straight to the machines. This is a text file, hopefully @Onoff and the like can fill in on the detail. Now the text file is just like a cad file in some ways... the lines start to get blurred here?

I use cold formed C sections from time to time. Couple of examples. One was loft conversion with rear dormer was really tight for height. Could not go above the ridge line and had to maintain 2.0m ceiling height on the inside. Eventually after exploring a good few options I plumped for a 140mm deep cold formed cee section with insulation on top.. a warm roof so the steel is within the the insulation envelope thus avoiding many condensation issues. In many ways it was the geometry of the conversion that forced this solution, tricky connection details, other ventilation issues and these kept closing down the more convensional solutions you see on many attic conversions. Another example.. Client requirement to minimise disruption to the floor below and maximise attic floor to ceiling height. Need to span some 5.0m with some relatively big point loads from dormers.. and the structural walls below are all in the wrong place. The existing attic joists are 200mm deep with lath and plaster ceilings.. that must be kept intact.. no cracking! The existing attic joists are supported by transfer beams mid span. See some posts on BH where the roofs have a purlin supporting the rafters. The transfer beam is just like the purlin but at attic floor level. The problem is that this transfer beam has to go as if not it will end up in the middle of the new floor. To overcome this shallower back to back cold formed Cee sections between the existing joists to span the 5.0m are introduced. This works well as the cee sections clear the lath and plaster and leave room to run electric cables and small bore pipes. Also, as the walls below are not in the right position the cees in places function as cantilevers. Now this all sounds awfully complicated but it's not. The sections are straight out of say the Albion / Steadmans brochure. One key here is also to use their standard punching pattern for bolting. Remember that these sections are used by the kilometer in industrial buildings all the time. One thing though is that you have to do your own calcs for these when say using them as cantilvers and off piste applications.. and the calcs can be very lengthy and time consuming unless you are familiar with cold formed steel design. Lastly to get the best out of you local builder it's good to provide the fabrication drawings for your cold formed sections in say the Steadmans / Albion , other formats. All the builder has to do is then send the drawings to the supplier. This is standard practice in the industrial sector. Often a local builder who just does say extensions is less familiar with cold formed steel in these applications , but if you hold their hand a bit they often engage. @Annker Keep exploring this as on option, even if to rule out at the end of the day.

Take a bit of time to digest and go back and read the other comments again from BH members. Play about on BH and read around, you'll pick up some great nuggets for later anyway. Then take a view on whether getting an SE feels right for you. I'm not strong on spelling either and get carried away as it's social media! Folk don't pay enough for a desk top study in general.. they see it as a box ticking excercise so they get what they pay for from the professionals. Nowadays professionals just provide a churn that looks good often with little value and try not to accept liability. It's a mess. No wonder there are reports floating about exploring why UK build costs are apparently high. I've done a few desktop studies and a good one takes time.. some several days / weeks to gather the info and then a day /s or so and a night/s to sleep on it. This approach has saved some Client a fortune that has well out weighed the cost of the study and mitigated the cost of the on site ground investigation.. The really hard part is to convince a Client that what you are doing is worth while! You can do an lot to help yourself here. I would put your back into it and do you own research, it's only your own time you are spending. I clicked on the link for the desk top study but for some reason it is not downloading? can anyone help?

Be careful what you wish for! Firstly thanks to all for all your posts have enjoyed reading them, there are many to thank but @the_r_sole is a font of knowledge who gives it to you straight up as are many others. Charlie.. it's very much doable. A few years back I embarked on a similar journey although I came at it from the SE / Contractor side. While I do my own design stuff and some "Architectural Design" I collaborate with in particular with one really experienced Architect. I have said to him in the past.. you don't need me (SE hat on) as your design is spot on. He just sizes the building / structural envelope and main beams say nearly always correctly, but he has been doing it for nearly fifty years! But then we start to play about. I put my Architectural hat on and he puts his SE hat on.. we are like "two old grumpy men" and the result is some elegant, competant, safe, and economic design. Oh.. I use the word elegant as this indicates that it will stand the test of time. The work is flooding in and a lot of it is repeat business coupled with some interesting stuff. So yes you want to do your own thing but find some one that can compliment your skills and recognise that you can feed off each other and learn new stuff... together. I advocate that a great Architect should also be competant in structural design, not the calculations but have to a feeling for how the building works and that includes how it stays up structrally. A great SE should be at a minimum competant in the principles of Architecture and have a bit of flair / artistic bent. Over the last few decades the professions (Architects, QS' SE's etc) have diversified and you can see this on BH.. no one is talking to each other and the Client is left in the dark. From my own recent experience I have found that going back to the "old way" where we all start really working together pays dividends. Yes there are a few Clients, BH members too that think it still pays to breakdown each design element to get the lowest price. The lowest price is not always the best in the round. See Ruskin common law of business.

Hello Zak. The thing I enjoy about BH is that you can chew the fat without getting your head bitten off. Have copied and pasted you text in italic with my comments/ fat! "Does this mean given its currenlty a banglow I will be limited to banglow (no build upward) option unless I go down the underpinning option which is a not an option at the moment." No. what we look to do is to see how we can redistribute the loads to "trick the ground" into thinking that nothing has changed too much and then we design for the little extra anticipated settlement.. yes my name is Potter but not Harry Potter, but do wear glasses. So I had two full bore holes and third extended via with dynamic probe with two trial pits as marked on the plan. If I need to do more trial holes I would need to get ot sorted via a professional but what is it I am looking for which could not be done previously. Sorry just trying to clarify my understanding. You need to take a few steps back and look at what you have on site, you just missed the earlier steps? maybe call these earlier steps a walk over site study, preceeded by a desktop study. But unless you do this all the time then you probably won't know this. Don't worry though, your GI is of much value. I don't think you have done anything wrong, maybe just got the order / sequence mixed up? I would put together a little "portfolio" on your project. A summary of how you came by the property, what you know about it, what you have done say planning wise, your research and so on. Include a title plan, the sort of things that show you have done your best to get as far as you can. Then a short bit on what you want your project to deliver, make it personal. Take that to a few local SE's and ask them if they can help. Don't mention fee cost at this stage. SE's know this is coming down the pipe anyway. You may well get a pleasant surprise and an SE will drop into your lap, pick up the ball and you can work away together finding the right solution for you. You have an interesting project here that is technically challenging and there are plenty SE's that love this kind of stuff.. provided they get renumerated at a fair rate. In return they will often seek to mitigate their fee by saving you money. So that is 4tonne per sqm. Would this be enough for a banglow only or traditional block and brick two and half (loft) storey house? At 40kN/m^2 ball park you could achieve two storeys plus the loft. Just don't be gready with huge spans, beam and block for serious acoustics. You can still create a great family working home future proofed. The trick here is to get an SE in early and they can work with you to support the Architectural design, which will help avoid you going down blind alleys and racking up design cost. Definitely, I would consider that if it's possible and a cost effective solution. I had a chat with Hilliard Tanner (Ireland) as @joe90 suggested and he was to going to look at it but he mention thin steel cases concrete beam with raft ok top among one option so I am keeping fingers crossed. By all means talk to Tanners but you may want to consider a local SE that also has a black book of local contacts, brickies, sparks etc and reliable local folk.. and hypothetically a really black book of who to avoid locally contractor wise, not that they do keep such a book as this may be illegal. In terms of insulated rafts you may see insulation load bearing values of 130 - 150kPa (150 kN/m^2) at 10% compression but put this in at 250 -300 mm thick and it will squash a lot 25 -30mm.. too much. Now what SE's look at is what can the building tolerate.. say 10mm as this has to be added to any ground movement. We look at the load bearing value at say 1 -2% compression and now were are down to a bearing capacity much closer if not less than the 40kN/m^2 I have been mentioning.

Hello @CharlieKLP Been lurking following this thread. I'm a designer with a penchant for structures. If you can hold your own on Build Hub then your future is bright! Wishing you all the best and will post a bit later on my experience for your to pick over.

@Zak S Za.. an after thought. When you are comparing piling quotes check what they require in terms of you preparing the site, access you may see mention of a piling matt. Much will depend on the size of the rig and pile type. Often they will say you need to have the site preped up to X,Y,Z talk about making it hard to compare quotes.

Hello @iMCaan Concrete founds are fine under water and as others say seepage at this level is quite common. If you are wanting to drain the site a bit I would avoid if possible placing the drains below the level of the top of the concrete found. What can happen is that folk go mad and dig deep French drains near their founds. If in clay soil this can dry it out in the summer and your building could settle. If in sand the fine grains could get flushed out from under the founds.. and they settle. I've seen this on old stone built houses / steadings / shallow founded corbelled brick founds etc where folk put in a new drain deeper than the existing founds surrounded by pea gravel and a few years later cracks start appearing in the walls as they have dried out the ground under the founds that have happily sat there for decades. Most of the time movement is caused by blocked drains and tree roots and that is what you read about on the internet. Thus when new building we don't think "the other way round"

Me too.. to add some of my thoughts to yours. Before you go down the piling route I would make sure that you rule out the other options first and can justify to yourself that you have given it your best shot. @Zak S "To me rebuild could only be justified if I build a standard 2 storey plus a loft kind of house. Given the foot print it could easily reach 600sqm but I onky need 450-500 sqm. But want to have decent size ground floor. To follow up on Joe's point I would also ask myself.. can I design something that uses part of the existing foot print only and retain the existing founds? Then add some new founds similar to the existing to "fill in" the gaps. You have gathered some info by way of your GI report but you also have an existing building sitting there. I would want to have a look at the existing building, determine it's age and also when parts were added and altered. You see this with old steadings.. as say a farm grows they add bits, change it to accommodate larger farm machinery and so on. Different loads are added to the ground at different times. Now this can be a mine of information as it lets you observe how the existing building has performed on the ground over many decades. You can see cracks, where it settles / heaves and so on. You can also calculate the load the existing building is putting on the soil under it's foundations. Already you have some hard evidence on what the ground can carry. This also gives you clues as to where you need to target any further investigation. Could be trial pits dug with a JCB. It requires some experience to interpret what do see, if a lay person don't be put off using your common sense. It's your house / project so have fun with it and explore what you see. The ask say the Geotech / SE folk to explain your observations. Also have a look at what is next door as the ground conditions can change a lot over a 100 metres, but right next door can provide the best clues as to what you may have just over the boundary and thus what you may have a few metres away. I have had a quick look at the GI report (only in terms of the house though) and while underpinning the existing founds is always an option it's labour intensive and if you have high ground water.. a horrible job and difficult to get right. So this means cost £. You have what looks like two water tables on the bore hole logs BH1 & 2. This is not uncommon. Very roughly the rain falls / your drains leak / you have old soak aways and want to put in new ones too. This water soaks into the ground and can get trapped on top of a less permeable layer, like CLAY. But below this layer of CLAY can be fractured rock or gravel overlying fractured rock, like sand stone and at this level lies the main aquifer. Often you find gravels / sands / silts before hitting more competant rock. This is due to weathering of the rock during ice ages and so on. This goes some way towards explaining the refusal term? The lower water strike can be a primary aquifer that the water board use to extract drinking water from so watch out if you want to start messing with it! Always check with the water board early just in case. The upper water level could be attributed to what is sometimes called a perched water table. The water gets stuck by a layer of less permeable material and can't drain straight down to the lower water table.. thus it is "perched". You see I have used capital letters above in places. You can also see this in the bore hole logs. Take borehole 1 log. At a depth of about 1.6m you find "..slightly silty sandy CLAY with fine roots" The capital letters indicate that the dominant portion of the sample is clay, hence in capital letters. Clay is less permeable than sand so it is preventing the water from draining down to the lower level. Now above 1.6 you have ground with sand and sands can transmit a lot of water. Yes there is a bit of made ground but this may not be extensive. Farmers were / are not daft and don't tend to build steadings over made ground. But they do often have a midden outside (MADE GOUND) and this gets picked up on a GI! Also if you pump like mad to keep your excavation dry you can suck out the fine portion of the sand, this weakens it and can cause a lot of trouble. Ideally you want to design a domestic found that is situated above the water level and avoid these issues if you can when dealing with sands. There is much discussion on BH about clays swelling and shrinking but if you can be sure they are deep enough and always saturated this won't happen. I won't go into great detail but you can also find fine roots at depth. Yes they will rot but settlements are negligable and can be accounted for. On the bore hole logs and in the "site work" section you can see they have carried out two types of penetration test. The SPT and dynamic probing. The dynamic probing is complex so I'll leave that for now. But the STP number provides the Engineer with a rough (well very rough) feel for what might be worth a closer look. A rough rule of thumb is to take the STP number and multiply by ten to give you an indicative allowable bearing capacity. The allowable bearing capacity is a measure of what load you can put on the ground (with factors of safety) without the ground failing or you house settling too much. Take BH 1 at 1.6 m SPT = 8 and BH 2 SPT = 9 at say 2.0m. Take the lower value 8 x 10 = 80 kN/m^2 ( 80 Kilo Newtons per square meter) which is about 8.0 tonnes per square metre.. quite a lot! But.. above this where want to put a found (could be a raft) there is water shown in you logs. Sands get their strength (bearing capacity) from partly inter granular friction in laymans terms. For this to work each grain bears on the ones around it and each particle has a density of say 20 kN/m^3. But when the water rises the density is halved (see Archimedes or the nautical members of BH) so you have half the friction. Thus when doing conceptual stuff we divide the 80 kN/m^2 by two when in SAND type soils to give an allowable bearing capacity (ABC) of 40 kN/m^2. Now you can often on a low rise building you can get a simple ground bearing raft with insulation under to work (with a fair wind) using an ABC of 40 kN/m^2. Make the insulation thicker and you are in passive house terratory. You may ask.. what about the roots rotting? Well we just design the raft to account for the ground settling a bit and the odd soft spot. You keep the raft as high as you can and away from the ground water. I would kick the tyres on this first before committing to piling, even if to rule the idea out and free up brain space. I hope this gives you a bit of further insight and is of use.

Yes, it's not ideal but the masonry bonding futher down is more appealing. If that joint is falling right under a truss suppot point then you may want to see if you can take off a bit of the wall plate and form the joints else where. Remember that you also probably need to fix a truss clip there. Roofs are quite forgiving under certain circumstances and up to a point.. look at many old roofs and how they sag. But also remember that you don't want a dip in your new ceiling.. this may irritate.

The GI report make for interesting reading. What are you proposing to build, how many storeys and do you have a rough floor plan?

In principle the half lap joint looks neetish.. what is less encouraging is the masonry below and it's bonding. Wall plates do an number of different things. One is to spread the load, another is to often act as a binder which ties the wall head over discontinuities in the masonry below. It may be ok but hard to say more without more detail / information.

All the best, make a list and pick their brains, offer to pay a bit more for the advise.. is goes down well. From an SE point of view it's often easier to spend half an hour or so chewing the fat with a Client than going through the process of invoicing, also a satisfied Client may just recommend you to their friends!

Hi Foggy. This is not uncommon, owning a house is a journey. Often it's beneficial when you get stuck to go back to basics. Start by going round the inside of the house and look at the openings.. doors and windows, wait for a windyish day and go round with the back or your hand feeling for drafts. If you have older double glazing you'll find a few. Often this is caused by the opening part of the window loosing it's shape as the glass holds the opening part square. What then happens is that the window does not shut right and make a tight seal on the gasket. Also the gaskets loose their flexibility so the locking mechanism has to work much harder to make a seal all round. Pick a window and watch some videos on utube about how you adjust the window / door mechanisms. Have a go at it so the mechanism is working freely. Next look at the gaskets. There are load of different types but you can get sample kits to help you identify what gaskets you need.. see link below for idea. https://www.handlesandhinges.co.uk/double-glazing-seal-gasket-sample-pack/ Now have a go at replacing the gaskets if need be, you are already on your way for little expense. Next run you hand along the bottom of the skirting and find the drafts, note the position. At the same time see if there is mould at this level and note the position. Look up the walls in each room and note the position of any damp / mould. Next go into the attic and see how the insulation is laid, check to see it is not touching the underside of the roof / tiles and that the eaves are clear and the insulation is not clogging the eaves ventilation. Also look to see if you have downlighters in the ceiling that might be letting steam from say the shower into the attic. The key in the attic is to look for places where you have moisture getting in and hitting a cold surface with no air flow. This applies elsewhere too. Now go outside and look at where the outside walls are most exposed, check you gutters, down pipes and that the rainwater drains are running clear. Look under the floor and see if it is ventilated and that the air space is not full of rubbish. See how it all works. Once you have got a handle on this then turn to your cavity wall insulation. Cavity walls in the 1920's were fairly new and the cavities we often smaller than they are today. The cavity wall insulation may be missing in places so look for odd mouldy spots in funny places, see if they marry up with the cold / exposed areas on the outside and ground levels that are say maybe higher and cooling the wall / stopping it breathing. You need to be a bit of a detective and read/ learn a bit but once you get a feel for things you'll have a much better understanding on how your house is working fabric wise. Next look at how you are living and using the house and identify the sources of moisture. Compare with your observations. Once you have done this you'll be much more informed and thus able to target your spend most effectively and or make a small change to your living regime. It may be that by introducing ventilation in the right place, cutting out the drafts in the wrong place and adding the odd bit of insulation delivers the best return. Then if money to spare you can introduce more technology. All the best.

Please be safe. You are building two storeys so odd / unexpected / bad things can start to happen and you have higher loads than say single storey. If you need to ask about the block strength then you don't have sufficient experience in structural design to make sure what you are doing is safe.. and be able to prove it now / later if you need to sell. Sorry to be blunt. What about running this by say an SE, they may be able to say.. hey you can save money here as you are over designing, but here you need to up your game. Ideally an SE / experienced designer should be able to save you more than their fee in the round?

To provide you with another level of security confirm in writing whether the quotation includes complying with all the current building regulations and recommendations ( Building Standards) in Scotland and the tender drawings. You'll be surprised how encompassing this can be.

Hi eandg. I'm guessing here as you have posted no plans or other info. Being higher if a different animal. I'm guessing but if you have 1.2m from the boundary then it's good to have a levelish portion for you to clean the gutters, walk round etc. have a look on the net at what is a called a reinforced masonry retaining wall. There are lot's of different options other than a gravity retaining wall. On the soft side this type of reinforced wall can be faced with facing brick on you neighbours side.. yes I know it may cost a bit more but in the long run you may want to be friends with your neighbours or find you need their good will if you need to later access their land for some reason. When / if you come to sell you maybe want to be able to say.. we have great friendly neighbours. I've do the odd job where you actually dig out a lot of the soil and replace this with ICF type blocks. What you do here is to reduce the sideways load on the wall (lateral earth pressure) as the ICF blocks are stable and much less dense than the clay.. Sounds bizarre but this can be a cost effective solution when looking at things in the round. You do have to watch the water table as ICF blocks float so you need to make sure you put enough ballast load over the top to avoid .. embarrasement. Post some sketches.. plan view and cross sections if you can / have the will, sit back and let BH members take the strain.

Hello eandg. Generally a 1600m retaining wall offers up a lot of options, provided the wall is not "structural"... say holding back soil that is offering restraint to your neighbours house foundations. I would start with the fun part! Could we use gabion baskets say and grow things out of them. Could we use gabions with cheep infill and face it up with some dry stone dyke with inset bench seating to compliment any outside seating area. What you do here is to create butresses and put seating in between. What about a timber crib wall, you need a bit of space behind them to install but a well constructed crib wall will last for many years and is accepted by say the NHBC as a solution. Again you can grow things out of them and almost create a water fall effect of foliage that gives colour all year round. There are many different types of retaining wall. For a lowish wall such as this a gravity wall is often a good option if you have some space. In this case a starting point for the base width would be about ~1.2m if you have a reasonably stiff clay and good drainage. The footings are taken down to the level where the soil does not contain any matter that will decompose, below the top soil. You'll still get some minor settlement but these walls cope fine with these conditions. What about posting more info on your site and the type of ground you have.. you'll get loads of ideas here on BH.

Hello iMCann. Unfortunately there are at least a couple of other things to consider. Generally a wall of 7.0N (Newtons / mm^2 compressive unit strength i.e each individual block) can carry a surprising amount of vertical load if the wall is loaded about it's centreline and not subject to other sideways forces. But beam and block flooring can introduce quite high local stresses where the beams rest on the blocks, an over stress can lead to local crushing of the block. The walls may also be designed to resist horizontal wind loads which cause bending (flexure) in the wall. Even internal walls are subject to wind load! Imagine you have a big set of sliding doors open and a gust of wind blows in.. it can load the internal walls sideways. It's usually not a problem on domestic houses but on large industrial buildings or houses with two storeys and a vaulted ceiling this "internal wind loading" needs checked. The flexural stength of the wall is partly dictated by the unit strength of the blocks. The higher the block stength generally the stronger (up to a point) the wall in flexure. I would err on the safe side and check first with your SE. Seems odd though that an SE would spec 10N blocks when 7.3 would have done. At the same time ask your SE how to phrase the question (so they don't give you the run around) to the supplier so you can ascertain the strength of the block if 10N are indeed required with some evidence to back up any claim they may make, even though the blocks are stamped 7.3N.

To put a different slant on this, but hopefully an encouraging one for BH members. After the Grenfell tragety the insurers that were providing PI cover to designers (also to the folk that manufacture cladding systems and anyone else involved) were lost and backed off, many were trying to figure out what would follow, what it all meant. The mortgage providers, who partly rely on designers PI cover and input were stuck as they are there to write insurance business..not to study the regs, fire design and so on. However. Things seem to be settling a bit for the domestic market as many houses don't exceed say 18m in height. The building regs Uk wide (fire) are actually not that bad for low rise structures so it's a bit of a less risk area. Unfortunately in the panic even self builds / extensions got caught in the net to some extent and lenders backed off. I have seen a big surge in the amount of info you need to provide when renewing your PI cover in terms of fire risk. It's gone from about one page to six or seven and you also need to provide a statement about.. almost how you see the risk..the insurers are really trying to cover all their bases. Fundamentally though, if you are self building / extending you can still have a timber cladding and a timber frame. If you are less than 1.0m from the boundary then it's an issue but that has always been the case pre Grenfell or not. Often there are other factors that make the fire design a mute point if close to a boundary.. privacy.. over shaddowing, massing and so on in terms of planning anyway. I'm mulling this over.. have spoken to a few folk that make a living as underwriters, brokers and lenders. What I did was when filling in my PI renewal form was to embrace the questions and lay out where the risk is. My premium went up by about 7% so good result as I was expecting it to double at least. Given my experience it may be worth while discussing with your designers what they would charge you to provide a lay persons summary about your design and the fire risk. The aim is to reassure and educate potential insurers. Always bear in mind that insurance companies need to write policies.. and they need you!

+ one. Add up the labout time to fix it.. you'll need to find someone with the artisan type skills to do it. Compare with a new covering with maybe a guarentee?

@MJNewton Thank you MJ for your initial post and the follow up. It is a great informative thread. A great demonstration of how a pragmatic approach, working together with suppliers / contractors / the technical advisors can lead to a good outcome without having to resort to stripping things out and all the grief that can bring. Thanks again. To add a bit of food for thought... Often you hear bad reports about flat roofs, like all things in life bad news travels faster than good in general.The contractor /suppliers / installers / roofers are the first to get it in the neck when you start to see ponding / puddles on the roof. If you are thinking about a flat roof then you need to take quite a few steps back to prepare the structure in advance.. this needs forward planning! To explain I'll use the following example. You build an extension out the back of your house. Much of the below also applies to new build. The roof timbers / joists.. could be metal and often span from the new front wall of the extension back to the line of your existing rear elevation. You often want to open up the rear wall of the house to give a more of an open plan feel. You need say a steel beam / big concrete lintel to make a wider opening to access the new extension. This beam often rests on the old walls each side and adds point loads where before the load was spread more evenly. These point loads travel down the walls and often adds a bit more load locally to the founds that have sat there quite happily without moving. This extra load often causes some extra local settlement unless say the house is on solid rock. Your new beam / lintel bends a bit in the middle. Near the ends of the extension the rafters are supported on a good length of wall, maybe the side /gable walls of the extension.. but half way along the existing rear elevation you have a found that is settling and a have beam that is bending. Thus you already have a dip that causes water to pond. Steel beams bend under their initial load say from brickwork / floors / roofs above.. then they bend a bit more if you have say snow on the roof. But often they go back up a bit once the snow melts. But timber is a bit different. Timber (concrete to a lesser extent) suffers from what is called creep, it's a natural material. You can see good example of this if you go into an old pub with exposed beams.. observe the sag / creep. BS 5268 for example recommends a deflection limit of 0.003 x the roof joist span for some applications. So a 4000mm span can deflect 0.003 x 4000 = 12mm! But with modern flat roof membranes you can already see trouble ahead. What happens is that the poor builder puts everthing in flat and level and a few weeks / months later it is no longer flat, the steel has deflected, the timber is creeping and the founds are settling locally. You then see ponding on the roof and start asking questions. If you look at each element in isolation it is often not much in terms of settlement / deflection.. but when you add all the movement together you can soon see how the flat roof now has low spots in it. In summary make sure your SE or structural designer knows that you are going for a modern " true flat roof" early on and this can avoid later issues.

There are often two mind sets.. 1/ To look at the wild life as a problem that interferes with your financial gain 2/ To accept that you are interfering with the habitat and make a serious effort to provide an alternative (during the build) and enhanced habitat once you have had your way.. development wise. If you are inclined towards point two then you can look at providing a "temporary habitat".. enhanced feeding, stacking cut foliage, even pallets to encourage insects, to provide shelter, natural food for young birds and a safe space for birds and so on to dive into if a predator is about etc. A building site does not have to be barren. Calvin you seem a point 2 type.. you have time now to act on the alternaitve habitat, supplementary feeding and so on. Take this approach and you will enhance the wildlife and not have to worry about the chimney. Then when you finish your project you can enjoy not just your new house but all the wildlife that has been turning up during the build.. what more could you ask for? Have to say ten out of ten to you for posting about this.

Keep it simple stupid. Have designed some houses with the plant rooms in the attic and it works fine. I would recommend that for future proofing you design the plant room in the attic so it can carry some good point loads from say a couple of really heavy cylinders.. say 500 litres each plus the self weight of the tanks. That is about 1.3 -1.5 tonnes working load. A lot of the stuff you see on BH is actually cutting edge stuff.. ASHP etc, the theory is explained in depth by the some members.. To do this easily (furure proofing) you can use steel beams or just position your load bearing walls.. easier to do. Also work your way down and put the manifolds in say the towel cupboard, laundry room if a big house.. you have good crisp bed sheets and so on, even put the manifolds in the bathrooms.. makes them super cosy! It's a luxery but let's just enjoy a bit of that! To afford you future flexibility separate the floors into zones. Put a manifold on each floor supplied by pipework of a decent bore. It won't cost you that much extra but you may well be glad later if this is your forever home. Yes, we have a wide range of heating controls available at the moment, smart controls and so on but who knows what will be available in the future. Best to run some good large bore pipes from the attic to the floors to give a plenty flow at a low pump head. In the future you can restrict the flow if need be but much more difficult to increase if the bore of the pipes is too small layout is restrictive. The laws of hydraulics won't change. I