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Will you be running outside taps off this also, for gardening / window cleaning / jet washing patios? If not, then I wouldn’t install one tbh, as the investment doesn’t ever look holistically kosher to me when I’m asked to include one for a new build client. Unless you’re maximising the savings by seriously offsetting your mains water dependable then I’d seriously spend this money on more PV which makes far more sense. Cost of system plus cost of installation, maintenance / cleaning filters, inevitable pump replacement, additional segregated plumbing system in the house, electrical consumption during operation etc etc vs just buying water from the mains doesn’t make sense at all to me, unless you go for a huge tank say 10,000L which WOULD make sense, just about. I’ve recommended to a recent few clients not to bother with RWH unless the size of the tank is a minimum of 7-8000L, as when you get a dry spell <2500L of a typical 3000L tank will be gone quite quickly and you’ll be back to running off mains supply anyways. When it’s raining there’s more water than you’ll need even for outside taps etc as the garden is already wet and you’re inside in the dry not using them / washing car / windows / patio etc. Then add the inconvenience of typically having to have an indoors break tank for the pump to fill, which means you then have a gravity feed to WC’s and W/M, and then that’s me out completely. Most modern cisterns won’t be suitable for such low pressure supplies, and I had to swap out the fill valves on the 1st floor WCs for one client ( who had already self installed the tank ). You’ll need ‘attic’ space to install this coffin tank if you want any useful pressure ( head ), and access to it for maintenance, plus accept the noise of it filling and emptying. Or, depending on the size of system, you may need an accumulator for attenuation if the gravity break tank isn’t an option. Another pita is, when you eventually need to run off potable mains water, that will be when you prob still have over 500L or more left in a 3000L tank, ( eg when the pump float drops down and mains feed system kicks in to top you up from metered, potable water ) and that 500L capacity is rendered unusable for the lifetime of the system. Not sure if some manufacturers state useful capacity vs capacity? Salespeople rarely dwell on negatives btw This system is designed to not fully fill the tank when consuming potable mains water, so, for periods of little or no rainfall ( aka summer ) the frequency of the pump running will be far greater than in the rainy seasons, further labouring and fatiguing the expensive pump. Then the mains filling ( run dry / failsafe ) system needs detailing; This is normally achieved by installing a rainwater gulley trap in the floor under the stairs / utility / other inside the dwelling, and a cold mains water feed then gets poured into this via a solenoid and an open pipe feeding mains water into a tundish > gulley, eg to eventually get to the tank but purposefully indirectly . FYI, you are NOT allowed to install the cold water feed in the turret of the tank as RHW is classed as Cat5 water ( as bad as sewerage ) and an A/B ( iirc ) air break between potable mains supply and the RWH must exist for water bylaws compliance. For a previous client, we ended up putting this into the garden shed, as there was zero chance ever of me installing a rainwater gully inside a residential domestic dwelling!! Plus the noise of the water gushing into an open tundish would be less than ideal afaic. That could be timed but it’s not recommended, ergo this could go into ‘fill mode’ whilst you’re trying to shower, sapping valuable cold mains pressure for extended periods of time, and often……. The pump failing once every 10 years will pretty much wipe out that decades savings for a small capacity system. Looks great on paper no doubt, but not in reality. So, no from me, unless the numbers make sense, which they don’t. Buy more PV instead.

Could the graphite be a lubricant, helping the polystyrene spheres fill the cavity rather than getting stuck somewhere and leaving some of the cavity unfilled?

Fantastic, what a lot of useful information, might take a little time to digest but very helpful. The worship space we are suggesting would be about 165m2 with vaulted or semi vaulted ceiling. There would be 37 linear metres of wall space suitable for radiators, would that provide sufficient effective radiators to heat the room from an ASHP? Yes, the existing Victorian, solid brick Chapel is is a nightmare to maintain, and we are for ever calling on the heating engineer to fix the boiler. The Chapel was constructed in a time when there was a membership of 200/300 now we are down to about 40 and outgoing funds far exceed income. We feel the sale of this large building and parking space, along with some potential grants, would possibly cover the cost of the new build. The sketch design we intend to present to the Architect includes two meeting rooms for community use, hire, meetings, craft activities, training, coffee room, etc etc. We feel that by offering a fresh, warm welcoming ambience suitable for worship, Sunday school, meeting/function rooms, suitable for community activities, that we would provide a very low carbon building fit for purpose/use by several future generations. The village does not have a village hall so we would hope to create a community hub as well as a Methodist Chapel. I feel it is our responsibility, as the senior generation, to try and mitigate some of the damage we have inflicted on our precious planet and this unique opportunity is a way of doing that. Unfortunately some people can not look forward and are locked in the past so our small supportive group here in the village have some persuading to do to convince the powers that be that a low carbon, sustainable building is the future. This land was bequeathed by a local member for local use, but not sure the powers to be see it that way. I can see that 3phase and off grid are probably not the way forward. What is an multi split air to air system, who supplies those? Sutton lane site plan 2 (1).pdf

What is the temperature of the inner frame, is it below the dewpoint for your RH levels.

Call your DNO, the company that fixes blackouts, not your supplier

I'm a Civil Engineer, but mostly as contractor. I loved working with Architects and other Engineers to optimise a project. To look good, to be brilliant value, but mostly to keep the weather out. I told them where the money could be saved, without cutting corners, they called me a philistine, then we worked something out. Please don't criticise any profession so wildly, as there are better and worse in all walks of life. But you must choose according to their skills. Some Architects are very practical, while some are 3d artists. You didn't choose Hadid or Gehry if budget was an issue in the slightest. You didnt choose me if you wanted a temple to yourself / city/ business. My view is generally that my job was to keep people and their goods, safe and dry for the next 50 to 100 years. Add a bit for looks. Budget? Working to a budget is not necessarily the same as getting best value....that is where specialist contractors come in.

I couldn’t agree more - it’s pure profiteering by the so called professionals. Any reason why you’re so keen on an aerotherm plus, and why you’re so keen on a warranty? I genuinely feel you’ll do a better job and save yourself a ton of cash doing it yourself. The plumbing couldn’t be simpler. Tank temperature sensor, 3 port diverter valve, power supply. Just watch YouTube 🤣 All jokes aside, all the g3 stuff is in an approved document, just follow that. Pay BC to come and inspect it, or don’t.

Yep. IP56 as a minimum As you point out IP55 and IP65 give the same level of water protection.

As you say your spark will need to be comfortable but from my somewhat rusty memory of that aspect of the regs so long as the enclosure is properly rated (including sealed covers over the mcbs etc) there should be issue. If you ever look out the back of a tent at a festival/event/concert you will see an absolute forest of outdoor rated distribution boards, often on very substantial 3 phase circuits. They are usually one-piece rubber boxes with screw -tight lids. I think you would probably need a non-conductive unit as the earthing/bonding arrangements are usually different outdoors so a metal unit could be more complex in that regard depending on the details of location/circuit design/etc.

My experience over the years with Architect's is most are not practical and good at spending your money You can get by without an Architect But not a SE

I made what is in effect an external CU using one of these https://www.tlc-direct.co.uk/Products/CMSB504015.html It needs a simple key to open so can't be fiddled with by any random person and it is mounted under an overhang so isn't subject to direct rainfall. I would be uncomfortable fitting something like that where it could be subject to direct wetting, probably irrationally.

We hang our washing on a rack in the bathroom. Despite being used for three showers a day clothes dry in 12-18 hours thanks to the mvhr. It doesn't take much air flow to dry clothes this time of year wen the air is dry.

They may help flow by reducing the static electricity charge. That would help in the 'packing'. Interesting idea.

Graphite in eps is an infra red blocker (absorber?) used to improve thermal performance.

Possibly this 5 port switch just 40mm * 40mm. https://botblox.io/switchblox-industrial/ A sizable December?

Our stove gets about 3 mm taller when hot and this caused some movement at the joint between stove and stove pipe. Doesn't seem to have caused a leak though. I guess I should throw in a reminder to install Carbon Monoxide detectors in any/all rooms with a stove or flue.

Yes. I have two marketeers sitting behind me. (expletive deleted)ing hell do they talk complete bollocks. They are only good for colouring in charts.

@Adsibob When I was lecturing, the university decided to check all the lecturers' certificates. Was interesting who left before the deadline. One law lecturer, who was also working as a JP had no relevant qualifications at all. They took her to court I believe. Another, who claimed to have a Doctorate, and in his words, 'I don't need a PGCE' happened to have the same name as someone that had genuinely done their doctorate though the university. He left before the deadline. All his students knew he was a fraud. It is a shame that there is not a central database where qualifications cannot be easily verified, same with professional insurance. May stop the term 'engineer' being miss used.

Just say your house insurance company has asked for it. I occasionally get asked about my insurance (as a structural engineer) and I include details of my Professional Indemnity insurance in my T&Cs. I'm not offended - I'm designing something that affects what is most people's most valuable asset. Competence is via referrals, reviews, seeing examples of their work and so on.

SuperBead has a declared thermal conductivity of 0.033 W/mK which is exactly what I used to calculate your cavity wall loss after insulation (same as mine). They are graphite coated which makes them perform a little better than uncoated white beads. They say it's injected with a binder, which is good as it means the beads stay in position. Yes, they seem fine. The installation company should send a surveyor to you first to establish the suitability of your property. If you decide on this, make sure you're present when the survey is done and sit on their shoulder - be nosey and ask questions. They should drill a hole in each elevation and put a borescope (camera) into the cavity to check its condition.

Hi @Nickfromwales We have a small tank in the loft with a potable mains supply via a double check valve feeding ball valve 1, and a float switch operating a pump on the rainwater side feeding ball valve 2. The loos are then gravilty fed. The ball valve on the rainwater side is an over filling precaution along with the overflow pipe. M

The new dryers with built-in heat pump are pretty efficient; https://www.energy-stats.uk/are-heat-pump-tumble-dryers-cheaper-to-run/ measured 0.78kWh for a load of washing. They're still loud, though, and need to be kept somewhere relatively warm, or they get damaged. We've moved ours from garage to kitchen this week and it's pretty annoying. Dehumidifiers aren't exactly silent either, though.

As our washer drier is too loud to use off peak, I'm currently hanging washing in our unfinished ES. I've a basic dehumidifier running on a plug timer for economy 7. If hung out in evening, everything is dry by the next morning. Think it's using about 1.5kWh, so about half of what the drier would use and it's a double load. I have the dehumidifier set to constant running.

This should help: The male end of the stove pipe for wood burning should always point down and/or pointing at the stove. Also, the wood stove pipe should always be inserted into the collar of the wood stove outlet. From: https://www.rockfordchimneysupply.com/blog/correct-direction-to-install-wood-stove-pipe/

Agreed most or all of the above. I put a 10m3 harvester in for our own office...no client wanted one but we would test it. 100% of roof water into tank. Double the suggested size. It never ran out of water. The big bonus was that sewage charge was based on water use, so also tiny. And small water pipe in reduced rates. Saving apparently huge. Environmental benefig big too...less water bought and disposed of. But I have no idea the electric cost for the pump. The pump broke down and polypipe weren't interested. Got a repair eventually. Pump broke down again. Leased the building and tenant not interested so harvester sits unused as an expensive manhole. Moral....I might do one for myself, but wouldn't recommend it. But rainwater butts are simple and good as are soakaways and ponds.

I think it just determines drying speed past a certain point. For example, my dehumidifier has a laundry setting which goes full blast for six hours with a target humidity of 35%, idea being you shut it in a small room. I don't use this as I find just leaving it at the standard 55% with doors open dries plenty quickly enough, maybe 12 hours? The dehumidifier is right next to the clothes and spikes to 70something when they first go out. Clothes feel bone dry by the time it's back to 55%.

A financial advisor recently recommended that we only consider fixed and tracker mortgages. Fixed are fixed, so you know what you pay each month and trackers are a fixed percentage above the base rate, so is transparent whereas variable/discounted deals are at the entire discretion of the lender. They can pick and choose when and by how much they change their interest rates by.

Entirely your prerogative, and a reasonable position to take. Other BCOs may take a different view and be perfectly content with it, and they'd be no less right or wrong than you in doing so. The BRs simply aren't specific enough to be able to draw a specific line on this, and their aim is only reducing risk to a 'reasonable level' - not completely eliminating it otherwise we'd also be discussing the need to put in measures to stop people putting wood-filled wicker baskets on their hearth (raised or not! )...

Just to elaborate on initial high heat demand when first turning on the heating. Here is the last couple of weeks data for my place, turned the heating on 17th November. Settles down to around 14 kWh/day. This includes DHW and everything else.

If in doubt go back to the short bit in green. You may then have to explain the logic and low risk of your proposal.

I agree, it sounds like you have never had to heat this house before and so maybe the heating requirement is coming as a surprise. A 1950s house with no cavity wall insulation is going to cost a lot to heat. I would assume around 2000sq ft and maybe UPVC double glazing? Taking a guess at wall U-Value of 0.4 floor and roof at 0.15 and windows at 1.2 gives roughly 75-100kWh a day of heat input required at 21C depending on the outside temperature. Hot water on top of this will add a further maybe 15kWh a day. Your use is consistent with this. The 5kWh a day you were using before was around 15kWh of hot water at a COP of 3 which sounds about right. I would also think it is likely that the heating flow temperature has been set to a higher temperature considering the fact that you have radiators and a poor level of insulation. This will reduce the CoP of the ASHP and make it somewhat less efficient than it might be. You might get a COP of 3 instead of 3.5 for example. It does look as if it has maybe been installed in quite a tight corner which may not help. A wider picture would help.

The difference in mortar colour is because up to DPC (if it’s there) will have been built in substructure mortar & from there upwards in superstructure (probably silo) muck. Is the wall actually wet to the touch?

If we wanted be be clever, we could cater for the higher vat rate and duty via the website. As it is, i like simple. So effectively, we take the 3% hit on the extra VAt and another 3.5% on the duty in the case of ireland. But we could have a function that as soon as you entered your country, it recalculated the cost to reflect that. The shipping is what it is. Thats not changed. We always charged higher shipping costs to ireland than the UK. Because it costs more. Pre leaving the EU, there were proposals to charge the destinations country VAT rate, in order to avoid those in high rate VAT countries purchasing from low rate ones. Dontr know how far that got, but it was inevitably coming. My point is, if you want to make it an easy transaction for the customer, you can. It only falls over on low value stuff, because DPD charge a smalll fee for managing the payment. Its a flat rate per shipment. Our irish customers see no extra cost post brexit than they did before. Im happy that some of our competitors dont want to do this. All the better for us. Edit to add, i didnt actually answer your question, what you "should" be paying, is £800 + shipping. Then on arrival, duty at the appropiate rate, and VAT on the cumalative total. Anyone charging you VAT on an export is either incomptent or a crook. Theres no complicated paper work. The invoice and the shipping details proving export is all you need to retain to keep HMRC happy that you didnt charge VAT. And your VAT return reflecting the correct numbers. But you have to do all of them anyway. Anyone trying to charge me their VAT on somthing they were "exporting" would be told where to go in short order.

If I knew a year ago what I know now I may well have gone MBC.

I think 3 x bathrooms is fine. You could segregate the shower + Lav in a small room off one of the bathrooms if you want to get more utility. Re trees, agree completely. Plant fast (10 years), medium (20 years) and long growing species concurrently and hack them down at appropriate intervals before they get too large. With this I've narrowed it down to elbow space as the only real requirement. 1100mm for me. We have 2 x 1400x900mm showers. One with the shower on the short side, one on the long. Worlds apart in terms of comfort. A 900mm corner shower is fine if you can stand in the diagonal. Completely agree, we have a dressing room style bench for boots underneath and hooks on the wall in our utility adjacent the front door. Beside it are pigeonholes for shoes. It is about 3m wide. It should have been 10m. Every outdoor coat gets hung up. Schoolbags similarly. I was determined to not be a Nazi "shoes off house" but yet because the floors are warm everyone naturally dumps their shoes. You need storage here for EVERY shoe and coat in the house IMO. A proper area for indoor drying of cloths + bedsheets etc is very handy. I'm typing beside a banister covered in various drying garments as we speak. A pull up rack of maybe 6m2 would have been excellent. A vaulted ceiling over the entrance might be a good option to avoid the dead end cupboard. I don't know your position re kids, but I wish we could have built a carport avoid the rain when bringing kids into and out of the car. Good on you for sharing. Gives us something to keep the mind active on a Sunday.

Agree on point 1 above. We had this exact problem in the previous house. Very annoying. Tried to design it out in the self-build but the best we’ve managed is this. I originally had two front doors, one into the utility room and one into the lobby. The plan was to ‘hide’ the door into the utility room somehow. Ditched that idea so have arranged the front door and util door so that shoes and jackets are kept in here. Our kids have grown up moved out now so no more piles of stuff inside the front door.

Couple of things: 1. Huge mistake not to have far more storage, or vestibule, near front door UNLESS you and your family will be using the back door and front door will only used by visitors and is effectively a decorative entrance. You are making exactly same mistake I did, by not having vestibule and sufficient storage near front door. It will look great on plans & when you move in but unless you have somebody on hallway patrol and very disciplined children, you’ll find stuff piles up in a real living scenario. I’d put more hallway storage from hallway by using some of the cupboard space in the snug. Unless you like the lived in messy look which I suspect you don’t. If you have visitors where will their coats and shoes go ? Please see my attachment photo - this is tidy for us 2. Agree 100% about putting large walk in shower in master en suite, like the main bathroom Especially if you are likely to shower a lot. You have a big en-suite and a corner shower in there would look naff and function even worse. A lovely big walk in shower is one of the decisions I got right in our house. 3. Plant room store. The pumps and internal grubbings of an ASHP system can be quite noisy. Yours is underneath bedroom 3 . Ours is under our master bedroom. If you can’t move the plant room to underneath non bedroom, please put proper designed acoustic insulation in the plant room and ceiling/floor area. I like your design as I’ve previously stated, and I think your trying to build something with similar to us in terms of use, and design “sharp and neat”, but just wanted to let you know your are likely to be making a couple of layout errors that I definitely made - if you decide to progress exactly as is.

GF plant room may be a bit cosy depending on what is going in there. Our is 1.8m x 1.7m with MVHR, home automation cabinet, UFH manifold, gas boiler, soil stack, BT fibre. I wish I had made it larger as some of the electronics ended up in an airing cupboard upstairs (Sonos amp, LAN switch, NAS drive, CCTV kit). The MVHR unit and associated ducting being the largest item by some way in the GF plant room.

You don't need internet for that. Our heating programmer has a "holiday mode" where you tell it the dates you are away and the heating is off for those days. We set the return day 1 day before we actually get back to give it time to heat up.

also swing the toilet doors to open out not in, wont have hassle with disabled regs and spacing. ref openings, quite easy to do. for example you have a 600 window on the plan, architects do this as they are clueless on how to build normally. 600 / 225 (brick + joint) = 2.66666 bricks. result = looks crap. yes some runs the joints can all be stretched etc etc but just make the window 3 bricks and its 675mm then the cuts are exactly half.

+1, I had my brick Layer use whole or half bricks only then got windows and doors made to fit the openings. Looks far superior 👍

not a fan of doors on the outside walls upstairs opening to nowhere. Most of your window sizes dont work brick, spend 15 mins with the builder and adjust them all to work. saves him time, you money and no crap cuts to look at forever! lot of wasted space on the landing. Stairs need more thought. Fireplace would make a nice feature.

I would look at the position of the toilets in each of the bathrooms on the first floor. Ideally toilets should be mounted on external walls. It makes them much quieter than having them on internal walls, particularly if the other side of the internal wall is a bedroom, as is the case with most of your toilets. Sometimes having them on an external wall can also make the waste plumbing easier.

I've done both, but the sink is intentionally tiny. It has an insinkerator (waste disposal) so basically I can prep on the island and shove waste into the sink. Can't fit any plates (that's what the second big sink is for) Also I find the dead end in the stairs somewhat strange. No idea what to do about it at a glance but I would try to incorporate it into the master. Would make a decent walk-in? Finally I guess this is mostly personal but this feels like a house for a 10-head family. So many individual living spaces downstairs that are each small. And the space facing the sun is somewhat limited. I know this point would require a major redesign to 'fix' but have you outlined your daily routines? Do you have a bunch of people that come together in dining but then all want to retreat to their own spot? Again, personal choice really but I myself created a huge living space where everybody is during the day, with one big office/secondary seating (if you're fighting or hate the movie is playing ) and other than that good upstairs amenities.

I suppose if you use a profiling tool designed for caulking baths etc. you could get a neat concave bead at the junction. It would give it some decent contact area. Better than a big coving unless that fitted in with the rest of the property.

You can either buy pipe clips that are split lengthways and clip around the pipes, maybe called rad snaps, or buy something like these. https://radiatorvalves4u.co.uk/500-radiator-pipe-shroud-130mm-long-brushed-copper/?gclid=Cj0KCQiAj4ecBhD3ARIsAM4Q_jFK8hVmeIjPzYSJcCcgfNrj4emtMvOcPXF4129rJTGDhiVDEabp9wQaAhctEALw_wcB

The advantage of an ASHP bigger than needed for space heating, would be quicker DHW re heat times. But it would not be able to modulate down low enough for heating needs so would indeed be cycling more.

Get the installer back, get the flue swept and get him to test it with a smoke candle. As above, the joints in the flue are not necessarily sealed because a flue should be drawing air, so any leak will suck in air from the room, not expel smoke. I would be looking at the MVHR setup or just turn it off to rule out depresurisation of the house. Is the stove room sealed? or does it draw air from the room? if so is there an adequate air vent close to the stove?

Hello GlanMenai. You're off to a good start with your questions and research. Hope this helps a bit. To progress.. it's a good time to seek some professional advice. This could be from an experienced Architect (basements) or a specialist basement contractor if you have some contacts. Most often an SE is the best place to start as you'll need them anyway at some point so best to get them in early. I'm assuming you have an idea of what you want to achieve layout wise so this is more of a "structural" undertaking as you have a defined footprint. Most SE's say follow a process which is akin to this... 1/ Introduction.. meet.. discuss what you want to achieve, your "soft requirements".. warmth, light , bathrooms (this is to get a handle on drainage) and so on. You may want to create a lighwell outside to introduce natural light into a basement and this will involve making a hole in the outside wall 2/ Walk round the outside and examine the condition of the visible structure.. looking for and at; the topgraphy of the site (sloping or flattish), cracking, settlement, walls out of plumb, type of construction.. long list. 3/ Examine the roof layout and condition.. chimney locations and other features that could be heavy or become potentially unstable if some movement occurs when messing about forming the basement. Understand where the roof loads appear to be supported from the outside. 4/ Next go inside and up into the attic. Look at how the roof is formed and if the loads are evenly spread or are there for example large purlins transferring load to the walls in certain locations. Look for movement where the roof timbers join together. Often this can give an indication of how a building has settled over time as you can see how the joints may have separated / cracked over time. You compare what you can see inside with what you have seen outside. 5/ I'll assume the building is two storeys. Go to the first floor and determine which walls are the spine walls..usually brick. These are the walls that help tie the outside walls together, help resist the wind loading pushing the building sideways and maybe provide a bit of stability to walls containing chimney flues that need a "bit of extra help" to stop them moving sideways. It's also important to look for walls that may have been removed to enable a change in layout of the first floor. If the original layout has changed this is material as you may have lost a bit of stablity and tying for example. 6/ Go down to the ground floor and do the same. Here you often find that folk have been widening out openings in walls, putting in beams and this introduces point loadings which were not there when the house was built. All the time looking for signs of movement and "odd stuff" 7/ Lastly look under the ground floor. Look at in particular the areas where you think there may be point loading (that is why you start at the top and work down) examine the condition of; the mortar / the bonding of the masonry/ the quality of the original workmanship. 8/ There are are few expert plumbers and sparks on BH who know not to knock out large holes in the underbuilding..but often you find that a "cowboy" has smashed large holes in the underbuilding with a club hammer. In some cases you can see that the building is starting to protest but has not got to the point where this is visible in the living space. But one more "knock".. what then? 9/ Lastlyish examine the solum. Is it earth and what is it made up of? Can you see evidence of water rising, lots of salt deposits, signs of flooding.. again it's a long list. Now you have done your "Columbo" bit .. digest. GlanMenai.. you have gathered some info on the founds, well done. The next stage say for the SE is to have a look at the soil. Soil types are a massive subject so I'll leave out info on all the different types, already in this post folk are alluding to this and there is plenty on BH about clay / chalks / rock an so on and how they behave in different ways. To cut to the chase the SE will probably already know what generic soil type is likely prevelant in your area. A thing they will always be keen to determine is what the ground water conditions might be. This is fundamental to making head way as water can have a big impact on the capacity of some types of soil to resist load, remain structurally stable during construction (sometimes called stand up time and water management) when you are forming a basement (doing the work) and after completion. Clearly you need to know where the water goes as this will drive the design of the water proofing / drainage. Remember that insulation floats so you need to make sure you don't create a boat.. your floor could lift! Once you have gathered the above info you can then get to the exciting bit where you can explore the different insulation options, UF heating solutions and how much depth you need to fit it all in. It's stating the obvious but the deeper you go the more risk you run in certain types of ground. On the other hand there are some types of ground where you can pretty much dig to you hearts content.. within reason. Lastly, even if you are just intending to dig no lower than the level of the existing founds please get your proposals checked out. What you can do is remove what we call the "surcharge" which is the weight of the soil above foundation formation level. This apparently small weight can have a significant effect on the founds if removed, especially on old buildings that may have been mucked about with. Also, you can change the way the water drains under the house and in some cases this can result in unwanted movement. If you follow this process you should get a good understanding of how your house works and this could open up other avenues to explore that you may have not yet thought of! You may also save some money! All the best with the project.