Bitpipe

I echo all the good advice above, avoid 'greenwash' and the implication that a low energy house (I'd like to ban the word 'eco' - a Grand Designs disease) imposes a lifestyle on the occupants. MVHR is a good example - provides energy efficient ventilation to your otherwise airtight home by harvesting the heat that would otherwise leave with the stale air being extracted. Some people extrapolate this to 'you can't open a window in summer'. Of course you can, winter too if you like. Our slider was open for hours yesterday as the dog pinged in and out. Invest in good fabric design and attention to detail when building. Treat the house as a system, not a set of unconnected functions (e.g. heating, DHW supply, ventilation etc.). Pay as much attention to summer overheating as you do to winter cold. You can spend money on capturing waste heat from your shower, use rain water to flush the loos and even try and recycle your grey water but you quickly enter the world of diminishing returns where you spend much more than you will ever recover in benefit.

Certification costs money and constrains choice of some kit like MVHR. I know that my u values exceed the requirements and my airtightness test came in at below 0.6 ACH. The PHPP modelling was as far as I went. Final SAP rating was 91 (A) so happy enough with that. What kind of foundation design are you using? Many here have used the MBC passive slab, we did a variation on that theme by building a passive basement with twin wall TF on top.

Did you pay a premium for the founds being in situ? What would it cost a man and a machine to grub that up & dispose? I think you will struggle to get a passive standard house to work on those foundations - as you say, not enough depth to get decent insulation in especially if you're considering a low temp UFH solution which usually works well with the low heating requirement.

My instinct would be to remove that screw and see what's inside...

And welcome Another passive house builder here (2016) not certified though but meet and exceed all the requirements. Quite a few here have achieved similar with different build methods. Tell us more about your project!

Yep, but I should have checked so it was on me. The error was really just aesthetic as cost was same and it fit the aperture so could have been worse! I know our window company was tortured by their supplier's system which regularly reset everything after making a minor change, caught a few issues there that would have been painful. Lesson is to double check and double check again.

The sad truth is that very little of that will have any inherent value beyond basic scrap metal prices. We had a similar era building and could not even give away the 1500 unused and stored bricks from its original construction (original owner had kept them for a future project), never mind other bits and pieces. It has to be quite special to be of interest to a salvage yard, most stuff is not worth the effort to remove it without damage and re-condition for future resale. Also slows down your demolition and increases the cost. Good idea to keep rubble etc, perhaps look to hire a crusher if that works economically to keep such material on site and avoid it being taken away and then bought back again as type 1 sub base. Just make sure it does not get in the way of the build itself.

It should not be difficult to calculate the point loading in this environment. You then chose an EPS grade that just exceeds that. https://insulationcart.com/knowledge/about-products/expanded-polystyrene-eps/108

The number that comes afte That number refers to the compressive strength of the EPS - the point load in N per M2. When you put EPS as part of a foundation system then its very relevant and is specified by your SE. The EPS under my basement slab is 200 grade. Given you're using it on top, 70 is probably fine.

And Bloodlands (NI drama currently on BBC1) - just make sure they don't find the bodies.

Yep - you can get planning consent on land you do not own. Just means you are allowed to build it from a LA point of view not that you can legally build it with respect to land ownership. Neighbour tried to pull something similar with a covenant that existed on our plots, planners said 'whatever'. Do you think the objection to condition discharge is a move to get the boundary dispute 'on the record'?

Somewhat proportional to money spent and / or time to remedy.

https://www.myerson.co.uk/news-insights-and-events/a-guide-to-adverse-possession Go talk to a competent solicitor, one who has experience in these type of matters.

I carefully designed our £4k passive front door from RK systems to be 1100mm wide with 450mm glass to side (opening was 1650mm) for the desired 'big door' effect. Door arrived 8 weeks later and was 900mm wide with 650 glass. Checked the design and I'd made an adjustment but not noticed that the door size had reset to default. Was really upset for a few days but got over it and moved onto the next problem

It really is. If you're lucky it's a simple extension from the supply that next door connects to. If you can co-ordinate road works etc then the cost can be minimised - may still be substantial though. Worst case, if next door is on a spur from a distant main or the line they are on is at capacity, you can be faced with a very large bill. As @Dave Jones says, call / write to them now and start getting quotes. Always ask what is 'contestable' as you can get others to do that work for you vs their subcontractors and it may be cheaper. Usually related to digging, ducting and making good. Any crossing of highways will require permits and approved contractors to do the road finish.

This depends - while TF are more expensive up front, they are erected in a matter of days/weeks and you can then move on with your build. Depends how complete the package is and how valuable time is on your project. If You can get a quote from the DNO (local power supplier) for them to do the work and then see what's 'contestable' - i.e. they are ok with you doing - usually this is digging trenches, exposing the existing cable, backfilling etc. You can then get a quote from a local ground worker for those elements - add to the DNOs non contestable bit and that's your likely cost.

We only had two trades work day rates - joiner and landscaper. Everyone else was fixed price, supply and fit (zero rated obvs). Two major packages, one for demolition, basement and services; second for airtight timber frame. Everything else - windows, roofing, render, electrics, plumbing, plastering, flooring, tiling, kitchen, decorators etc.. was a standalone package. The joiner was finding it hard to size the job - he first came on the back of first fix and was there to box in services and put in door frames etc so we could get to plastering stage but there were lots of bitty jobs to do also (noggins for sinks etc..). Thereafter he was hanging doors, doing skirting and architrave and building a few bespoke cupboards in hall, etc. Day rate with us sourcing materials worked and he was a solid worker but the slow and steady type. However there was once or twice when I would think to myself - is that all you achieved today? There was always a polite way to ask how much longer a given job would take and was anything holding them back and he usually caught up with the initial estimate that we used to agree ahead of each specific job. Landscaper was similar, job was too big for him to estimate so we took it a week at a time and he got a lot done, came back for three or four visits over the year to get it all finished. I would advise against it as it's very trust based and even then you can get disappointed. Break job into logical chunks and get quotes for each bit, both from your local builder but others also. Also - be wary that your tenders are all coming back as over budget or 'silly'. The hard truth may be that your design and desired timescales and finish are over your budget and the local guy is telling you what you want to hear. When you run out of money he will be off the job and you'll be left with an incomplete build. What are the £/m2 for the tenders coming in at?

Just get a flat piece of steel and some of those fridge magnet letters. Gives you some future flexibility

Sounds like something you will need to get fabricated. Should not be that complicated as it's just folded sheet metal - you can get a paint shop to powder coat it to any RAL.

Sounds like an ideal summer project

I have 140m2 of 300mm EPS 200 under my basement (so holding up my house). Not sure why XPS is considered better? Bit late to change it now

Ours worked out at 6 beds and just under 400m2 - similar concept: basement, and 2 2/1 floors on top (rooms in roof). More or less 10mx11m footprint throughout with a utility room to one side (and plant room under in basement). Does not feel overly big to live in, e.g. bedrooms are 3.5m square but the basement adds a lot of extra space - kids have a den each and there is a notional gym and random room, both full of boxes. Rooms in roof don't see much use but handy when we get visitors (when that was a thing). Plot is a wedge 27m wide at street, 100m deep and 17m at bottom - so can easily take the house (which is about 50% bigger than what it replaced above ground). Worked out about £1500/m2 with most of build in 2015/16 and landscaping and other bits in the year and two thereafter. Being passive standard did not add much to the overall cost. We PMd with two main contracts (demo, basement & services / timber frame) with the rest being trades employed directly by us. I did the MVHR and some sweeping up. We sourced bathrooms furniture & fittings, doors, joinery etc but mostly everything else came supply & fit.

So the correct approach is - use a pump rated for DHW return and don't focus on a specific material. However, is the Wilo RS26/6-3 pump featured above compliant or not?

I have just checked mine (minor panic) on reading this thread. Grundfos UPS 15-50N 130 (p/n 97549426) Selectric Stainless - rated for domestic hot water return, available here for £221 inc. vat. https://www.plumbnation.co.uk/site/grundfos-ups-15-50n-ss-hot-water-service-circulator-pump/

If you have trades to call upon then you will likely find yourself in a pesudo-project manager role, which is not a bad thing. Handing the whole build to a single contractor will usually be the most expensive as they will want to make a margin on the project as a whole (this is their living after all) and they may not be very motivated to save you money here and there - they will largely be concerned with their own cashflow, keeping to schedule and preserving their margin. Initially low quotes often increase with 'extras' which can be stressful to deal with. Becoming the 'main contractor' will in theory save you paying them the same margin but in reality will give you visibility of every cost and the opportunity to manage them up or down. You will be best motivated to get 5 quotes for a job or spend hours scouring the internet to source materials etc. The ultimate end cost does depend on the finish but don't skimp on the fabric as this will determine the long term efficiency of the house. Do invest in a QS detailed cost plan for your approved plans and then take this as a template that you work to - give you immediate access to quantities for materials and works plus gives you targets to beat and helps determine if trades are quoting you reasonably.