Visti

We've gone with vaulted ceilings exactly because we don't want an attic to store stuff that'll never get used. Also, I'm of the taller pursuasion so I can't wait to have some decent headroom! I think that's what great about self-builds; you get what you want! But boy are there a lot of decisions to clarify what that is...

As @le-cerveau mentions, the size of ducting depends on the flowrate you need for each room. There are minimum requirements for these per room/type as laid out in the Building Regs Part F (ventilation). These are laid out on page 19 (Table 5.1a/b) and there are some good examples on pages 51 (#C4) and 54 (#C8) You can see on Ubbink's product page that there are several profiles (circular & ovular), each with various sizes to accommodate to the available space or flowrate requirements. These are an example of semi-rigid ducts which are ideal for a radial setup, but there are also rigid ducts that are better suited to a trunk and branch setup. Each system has it's pro's and con's as you can imagine. The major factor in our selection of a MVHR supplier isn't just the unit, but the entire ducting system that goes with it and how friendly it is to DIY install. Even the design of such a system (i.e. the placement of the extract and supply valves, lengths of runs, flowrates etc...) can potentially be done as DIY too, but these services are available of course.

I believe MVHR is apart of a larger philosophy of 'materials first' as my architect likes to say. That is, put your money into the insulation and air-tightness of the structure to reduce your heating bills in the long term. Depending on the insulation you may also have significant performance in acoustic reduction. As an engineer I am quite fond of the philosophy as it focuses on simple and low maintenance technology rather than complex systems that would be higher maintenance and prone to breaking... I really don't like moving parts! An MVHR not only provides ventilation but it is a good combo to further reduce your heating outlay whilst providing you with an improved environment (fresher air, filtered, quicker to dry towels/clothes etc...). For us it's a no brainier as all the above are #1 to #5 on our top 10 list of priorities. Out quotes have varied from £2k to £4k for the MVHR unit and the various ductings required too. Installation is often on top of this, but half of the suppliers wont even offer it. But as many will point out, installing a MVHR is a right of passage for many of the self builders on the forum!

No experience with GBS, but we're looking at going with Internorm who I know do timber frames. They're certainly not at the inexpensive end however...

Definitely 042

Love the style of writing @divorcingjack, that was a very good read As to the power floated floor... I'm 100% with you on that. Nice, simple, muted and clean. I dread the day we pour though. Hopefully April/May will treat us nicely!

We'll timed photo! Semi ominous too...

Rollercoaster... You think you've finally got it... Then surprise!

We are. It's going to cost us more due to the aluminium box section gutters we're aiming for, but it'll be minimised we hope via price hunting and DIY. Happy to share working section when we've got it!

We're awaiting a quote from Cladco at the moment; they haven't provided a working detail yet, however they have some decent instructions that details the DIY steps involved. I am certain there are other cheaper manufacturers out there but I've had limited time to do much more than just a quick good search. Do let me know if you find alternatives! Spot on the money @Crofter, those two are from Dualchas Architects. I had not however heard of R.House before though, that has gotten me excited to see variations on the same theme. Gives me a lot more confidence that this will work too (and that it doesn't have to be monochromatic!) Aye, we're going for it due to a combination of cost and DIY ease (relatively). What supplier did you go with in the end?

I suspect a good deal of the extra cost with cellulose is two fold: the cost of labour in the installation (already mentioned) and the the twin stud frame required. You're right there @IanR, that's for the whole wall but I can double check when I get back from germany. We'll be adding not much more to the wall. A single layer of fermacell internally and vertical timber on counterbattens outside for cladding, so I'll have to do the calcs for these. It's another reason why we opted for cellulose at 0.12, gives us some leeway!

Aye, count me in too. Not been on here long but that's not stopped all of you from helping me out a dozen times already! Plus, there's a high likelihood I'll be in the same pickle two years from now!

Found a decent technical drawing (in Dutch!) of the solution and how to hide the guttering. Looks viable and got as far as a rough cost estimate to realise that it's probably beyond our available finances... Pitty! Hopefully the diagram will be useful to someone else. Instead we've gone for a black corrugated roof with vertical timber cladding, similar to the ones below. We figure if 5-10 years after the build we still fancy it, we can always lay the timber on top of the corrugated steel/alu! I'm sure a few posters of the poem around the area will quickly change that...

Welcome! Internorm have some high end window offerings too.

That's confirmed my suspicions regarding the roof needing an additional layer to the timber. Good news is our original design already caters to corrugated steel/alu so we can simply timber over the top of that to get the desired effect any time after the build is complete (we're unfortunately not fans of the look, otherwise this would have been easy!) Equitone panels are really neat (literally) and could certainly fit the bill too. Anything grey to black that keeps a slick profile is what we're keen on. I'll enquire with them for some samples and costings. I'm guessing maintenance is minimal with those too. The full EDPM sheet looks really intriguing in that design you posted @Ferdinand... And it's almost like you read our minds regarding the rest! A trip to Dungeness sounds in order in the near future. We're huge fans of Core-Ten but unfortunately we're limited to no more than 30% coverage for certain materials at graven hill, that being one of them. Hence we're looking at alu beams in place of wood too. I'll ask about the posts tomorrow as they're new as of Friday.

We're planning on 4.8m at the peak, pitch starts at 2.5 and it spans across 6m. Like Peter we'll divide this into smaller rooms in some of which there'll be mezzanines. Both of these ought to help with the scale

We're looking for alternatives to Zinc as it is affordable following some pointers on here, but we're not sure we're prepared to rearrange all our windows to suit the roofing! Tail wagging the dog and all that. Hence we're researching timber for both the 1st floor for cladding as well as the roofing for both gables as seen in grey above. Prices for red cedar appear reasonable on iWood, yet there appears to be nothing online on how to apply it vertically nor on how to use it for roofing. We know it's viable following Dutch and Scandinavian designs (below) but there seems to be little technical info on how to make it work as a genuine roofing material! We're not opposed to WPC either, but again we hit the same problem; it's all designed to be decking and cladding only, and horizontal at that. Anyone with experience in using vertical timber as a roofing material?

Don't know I'm afraid as it was one our architect sent us without a reference! @lizzie did mention Guttercrest the other day who I know do a square profile, but no idea how expensive they are!

Another consideration to using metals with standing seams that our architect pointed out was that the windows need to align with the seams to avoid it looking like a mess: vs

Thanks for the words of insight and encouragement all! I think MBC can service this particular part of the build and it's one less thing I have to worry about. What I will need to do however is the design of my own heating and DHW system. Too many snake oils salesmen out there. Off to that sub-forum I go!

I've a dilemma which I am hoping to get some independent advice on, particularly from those of you with MBC builds! MBC have provided us an option to lay the underfloor piping and Trish has supplied us with significant detail on the specifications (16mm Pex-Al-Pex, 100mm spacing, contraflow layout etc...). Layed out on top of EPS (seperatly supplied by us!). All for a reasonable price (so we think). When we asked a heating system supplier to remove the equivalent from their quote we got a lot of warnings: - spacing may be too wide - does the pipe have an oxygen barrier (does Pex-Al-Pex?) - are they using cheap DIY push fit couplers and bends - unnecessary pumps, valves or actuators This has given us pause as I don't think I can answer any of these even after several hours of research. I'm tempted just to DIY the lot, but it then starts to run into the design and specific of DHW and heating systems which I've no clue where to start. Any advice or pointers to articles or posts that'll give me a decent start?!

Seconded

Welcome @pdf27! I can't speak from experience, but I can point to the excellent advice about costings and quantity surveyors over at this topic. QED: Quantity Survey's build in a LOT of padding. Taking a serious look at the breakdown of the costs, what was realistic and what DIY elements we could do turned our near dead in the water project back within expectations. There's even a copy of the excel spreadsheet somewhere near the end if you want to use it Another Aerospace Engineer! One of the Airbus variety?

I only just realised I never responded to this post! I really like the idea of incorporating a workshop whilst extending the carport which in itself has always been too short in my opinion. We've got a final round of major changes going to the architect tomorrow before we submit to planning, so it has been included and it'd better stick this time! We've also added a roof light to the 'bunk' room so that there is valley access from within the house. Once we've settled some of the big roof items like the cladding I'll have a look at how to secure the area both for moving onto the external pitches and for potentially storing hidden things in the valley (a bee hive would be great!)

Thanks @le-cerveau, that was a very good read. I'll be keeping that in my back pocket for a refresher before I start on my own installation in a few months *I hope* The CVC quote has certainly been the most substantial by far amongst all of those I've engaged, and they appear to have quite a balanced price given the spec of the unit chosen and ducting combined. I'm tempted to DIY source the components but I'm not sure I'll get it substantially cheaper for it to be worth the lack of support! We'll see following some more research.