Ian

@epsilonGreedy Your proposed system sounds very similar to the one I installed in my own build. Like you I wanted to keep everything as simple as possible. The main difference is that mine is a small 71sqM single storey holiday home. It’s built to minimum building regs insulation values and I have a bulk 1200 litre LPG tank feeding a combi boiler with u/floor heating. The combi also supplies all our hot water and cooking needs. I work full time so we only use the house at weekends. The heating is set to a constant 24/7 ‘frost’ setting of 12 deg.C but I have a Hive controller and in the heating season before we go there I remotely boost the heating on the Friday night to a normal temperature. Looking at the Hive app after the weekend I can see that the temperature stays at a comfortable level for about half the week. We’ve now been through 2 full winters and I’ve only used 850 litres of LPG so far. The LPG cost 30 pence per litre so I reckon our annual cost will work out at about £130 per year of LPG + the rental of the tank.

@joe90 Like you, our build is in a very quiet spot. Our own sewage treatment plant is a Bio Pure 1 and I've located the Secoh JDK-S-60 air pump in a separate brick built housing away from the actual treatment plant and there's absolutely no noise from the pump however we still get the noise of the bubbling air/water from the plant.

@ProDave if your’re worried about tile longevity choose a porcelain with a high PEI wear rating. Guide to ratings: https://www.builddirect.com/learning-center/flooring/porcelain-tile-rated-hardness/

the main risk of recessing the pump box is that it could potentially flood in a heavy rainstorm

That advice comes directly from British Standard BS5250:2002. Although its essentially still correct the advice has since been superseded by the 2011+A1:2016 version of the standard which lowers the requirement to 2x vapour resistance. The exact wording is: "....an AVCL, with a vapour resistance of at least double that of the [external] sheathing should be provided on the warm side of the insulation"

@recoveringacademic Coming along well isn't it! Well done!

You should be looking to use a 'F2' grade brick in locations below DPC which simply means that they are frost proof. (F2 classification is the equivalent of the old F/L grade). Not all facing bricks are frost resistant so it's worth checking.

@Triassic I guess what they are trying to say is that you should get rid of any surface laitance as this forms a weak dusty layer on the top of many if not most new concrete slabs. http://www.contractflooringjournal.co.uk/blog/why-it-s-essential-to-get-rid-of-laitance/

I've specified this type of tile for a commercial project although they were quite a bit larger than the ones you're looking at. The boss of the tiling company was happy to use them at first but his tilers found them to be very difficult to work with particularly the cutting and he had to change tilers in the end to ones who had experience in working with that type of tile. I think they did the cutting off site after a few disasters cutting them on site. Wastage was much higher than with normal tiles. Breaking large tiles gets expensive very quickly.

For the benefit of those reading this who are still at the early planning stages I would say that it's important to realise that the process is like a marathon rather than a sprint. However you decide to manage the process, whether you're still in full time employment or retired, make sure that the way that you're doing it is in a manner that is sustainable over a long period of time without putting yourself under unsustainable levels of stress. My own self build holiday home is only small at 71m2. The build itself only took 8 months but the whole process from first meeting with a Planning Consultant to finally finishing the externals on the 1.5 acre garden last weekend has taken us 5 years.

@JamesP the normal build up for a warm roof with an impervious roof finish like metal is to either (a) ventilate properly under the metal or (b) install a proper vapour barrier on the warm side of the construction.

Same for me....3 weeks from order to install c/w glass for Rehau Upvc with triple glazing

For England see page 30 of Approved Doc B: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/485420/BR_PDF_AD_B1_2013.pdf Either the garage floor needs to slope toward the outside and away from the door into the house (no minimium slope specified) or you need a step of at least 100mm. The idea is to stop spilled fuel flowing into the house.

@Ed_MK you can use a brick with a low salt content and don’t use Fairy Liquid as a plasticiser in the mortar as it’s loaded with salt

@epsilonGreedy his build, like many others here, has the underfloor heating pipes buried in the concrete floor slab without the sand/cement screed topping that is traditionally used. The concrete slab therefore needs to be laid to a high degree of accuracy as the floor finish goes straight on top of the slab. @JSHarris timber frame is also built straight off the slab edge rather than using separate foundations which also means good accuracy is needed.

@ProDave Not sure about Scotland but in England & Wales building Inspectors will accept a HETAS certificate as proof of compliance with the Building Regs. Your installer should be HETAS registered so, if the scheme is acceptable to your BCO, you would only need to reach agreement with the installer. https://www.hetas.co.uk/consumer/certificate-of-compliance/

Within reason the value will be whatever your architect tells them it is, however if they think he is gaming the system to drive their fee down then they will either want a cost build-up from a member of the RICS or they might use the quarterly BICS cost guidance notes which give construction costs per sq.m for various types of building.

The biggest single advantage of timber frame over masonry is that you can build a weathertight shell much quicker, especially if the timber frame is part fabricated off site. This can be a big advantage in areas of the UK such as Scotland, Wales etc where a particularly wet or cold climate can lead to long delays with masonry construction. For example, on my own timber frame build on a very awkward site on a steep hill in Wales, our shell construction only took 2 weeks.

As a general process the system in Scotland is more bureaucratic than in England and Wales where the system was privatised back in the 1990s. In Scotland it's still exclusively run by Local Authorities. They usually won't let you start on site before they make a full assessment of your proposals which can lead to long delays depending on how under-staffed the department is. It's a lottery but in the case of a commercial job I did in Inverness meant a delay of 5 months before we could start on site and then during construction the BCO was never available when we asked him to do inspections. Before he would sign it off at the end of the job he insisted on us opening up completed areas of ceilings and walls so he could have a look into hidden void areas at the work he should have inspected at the time it was being built (he found no issues btw). In Glasgow our client was paying the LA's overtime bill for their inspectors to try and speed things up.

Wow!!....and Local Authorities wonder why they are losing business to private Approved Inspectors! It's not often that I'm surprised by something to do with Building Regs but your description of what they want from you reminded me of the old days when I first started work as an architect in the late 80's. (and the system that still operates now in Scotland)

@oldcoop What they want varies a lot depending on where you're building. Scotland will be much more bureaucratic than England & Wales. Usually the minimum they will need is your final SAP calculations and EPC as well as electric & gas certs but the best way to deal with the situation is to write and ask them what they need from you in order to give you the completion cert. Don't volunteer info that they haven't asked for.

Just an educated guess but I’m assuming your build is in Scotland? The system there can be a nightmare and is very different to the one operating in Wales & England.

@Russell griffiths are you using the Local Authority for building control or an Approved Inspector? LA inspectors still use the 2 submission systems you described, however in my experience most Approved Inspectors are more flexible in the way they work and will approve things as you submit them. Make sure you discuss with them the most important items first - IE the things that can’t be easily changed later such as Fire Regs compliance, Part M issues, drainage etc.

No difference - the pipe size wouldn’t change.

@Tin Soldier the advantage of laying your flooring through & under your kitchen units is that it makes getting white goods eg dishwasher in & out much easier as there’s no lip in floor level for them to get stuck behind