MPx

No recent knowledge so unlikely to help, but FWIW: In 2012 we had a pile and ring beam foundation done due to unstable ground. Not a regular shape (you need support for any internal load bearing), but approx 55 linear meters using 44x 9m piles with a ring beam and a few pins cost £27,480.75. But how much for strip foundations in 2012 to compare - no idea???

I never expected it to be cheaper I always expect it to be better than getting professionals to do it Many years ago I did build myself a car - great fun to do and use. No carnage. The problem with "professionals" is that its inherent to try to make as good a living as possible. To do this they must take the minimum amount of time and move on to the next job. If there is any competition they price low to get the work, then work down to the price doing all sorts of short cuts and bodges. Any whiff of its not so much the price as the quality of work that's important to me and its like having "mug" tattooed across my forehead and ridiculous numbers spring forth - and even if agreed, the speed at all costs working methods are so ingrained the attention to detail still doesn't happen. Example: One of my pet hates are the plastic inserts that are used to edge tiles. To avoid that I spend ages mitering the tiles around window reveals and the like giving an even grout line all through. I expect a professional could do that probably better and quicker than I can - but none do - or at least none that I've ever come across and I've seen a lot of tiled bathrooms in my life. You see mostly plastic, some up market metal can look better, and some make no attempt at all and just leave the tile edge on show. But we all like different things and that choice obviously suits most. Me - I'd rather do it myself and get a "better" result.

Absolutely...but not sure about the timing. It depends how mature you think "passivehaus" is. When these things are new they are typically silly expensive and don't stack up. If deemed a desirable outcome then sometimes governments act to skew the market by offering bribes. Some of us benefited from that with the early adoption of PV. We paid a huge amount for our 4kW system in 2011 but it still worked out a good investment through FIT. Those adoptions encouraged the industry and panels are now widely available at an affordable level. My take is that passivehaus is still immature and won't make economic sense for most. But this thread suggests that for some (Nationals?) the difference is quite low. My experience on a single custom build is that its still a significant premium and wouldn't be worth it in a purely financial sense - but we still choose to do it for other reasons.

Very much sort of passive @JohnMo. But we are trying our best to fully buy in to the concept when mentally we're still old school bricks and mortar, heating systems, opening windows - so we're doing loads of stuff that's way outside our comfort zone. Eg We wont have a heating system - which seems bonkers - but we're trying to buy in to the numbers that say it wont be required. As you read, my point about our old house was that as "pioneers" in GSHP we took some costs on the chin but installed something that looked like a good thing to have and would work well for us. Obvs in the intervening decade and a half things move on. Most of that stuff is old hat now and much more "normal" costings. I realise there is a much more economical way - with stuff like @Oz07 and others suggest. But that to me is national Housebuilder approach. What is the minimum I can get away with and still apply a "label". My approach is the opposite. eg The concept demands airtightness. So to me the ideal is airtight. Because that's very hard and as always the few % cost a lot, you can get a certificate if you hit a certain number so why not just hit the number. Well because its possible to do it better than that so why wouldn't you? I'm not interested in certificates or labels I want to experience the concept working at its best. This thread is about the current additional cost of going passiv. Some are arguing its a minimal uplift. I'm saying I'm seeing some huge numbers to make the jump. You're arguing that I'm just being daft and doing it all wrong. All of that likely to be true.

Well a change there then @Dan F. Latham's (Timber) wouldn't do it on the basis that I needed an FD30 cert and that has to come from a licensed processor - and they told me that PrincipalDoorsets was that for the UK. The quoted door is a Moralt 98mm Ferro Passiv Firesafe EI30 door kit. So it looks like the extra 30mm thickness is £5k!! Latham steel doors couldn't supply a door to spec.

To me the barriers are many fold: Finding an affordable plot in a place you'd want to live Finding an Architect who is on the same wavelength Getting through the broken planning systems - including paying for endless reports by "experts" Dealing with endless planning conditions Dealing with endless Building Control issues Finding out enough to make an appropriate choice on construction method Finding a builder and/or trades competent in their work, affordable, and available Having to make many many decisions on little information and only idealised drawings for reference Lead time from initial idea to moving in date measured in several years. Or you can just put up with the utter c**p thrown up by the nationals and shortcut the whole thing to a few months.

I agree...not economically viable - and indeed may not be true as @Dan F had a different experience... but you can only search for so long (and "stupid" is a bit pejorative) I would say though that its not all about the money. When we did our last project we were very early adopters of GSHP technology (in the UK). Including Groundworks/GSHP/Underfloor Heating/Specialist Rads/wiring - cost us £60k and I did most of the labour (everything except the Groundworks/GSHP install and commission). We could have had an LPG rad system for about £12k. We did get a small grant and a seven year bribe, but it was still 3x the cost net. Why would anyone do that? Well it was what we wanted, it worked incredibly well, suited our at home most of the time lifestyle and had relatively low running costs - but we certainly could have found a cheaper solution.

Interesting - the £7k one is a Moralt door. Didn't get any joy from Moralt directly (told they don't deal with the public only wholesale). But was put onto Principaldoorsets in Barnstable who provided the quote for a Moralt door of the appropriate spec.

I guess I could but that's not been the approach thus far. The Architect recommended a full plans approval. So the dialogue was between our architect and our (private) building control. All the nonsense was bottomed out in email argument before we started and "approved" so now I just meet our inspector Danny on site and he takes pictures of stuff to show that we've done what's been approved... Annoying that mistakes get made with the rules and even more annoying to me that so much is open to "interpretation". But I just prefer to think of it that those battles are behind me now.

Yes, as our walls will be some 400mm thick we could support a double door withing the aperture and we considered the FD on the garage side and the passive door in the hall, but what a pain to use, exacerbated by the self close on the fire door. Integral garage a part of our brief. Drive in and enter the house out of the weather. So part of the design. But as it doesn't appear to be possible to make an operational garage airtight or thermally efficient it has to be outside the envelope. Building control also working against us. Nonsense requirement to have a 150mm step between garage and hall - no doubt mitigating risks that no-one has ever seen materialise. Working opposite to the requirement to have a level entry to the front door. By definition there must be a step or slope if the garage is 150mm lower so "level" is not a possible outcome. We're just trying to make sure we're able to manage life with mobility issues should that come to pass - but hopefully it wont!

Well we're finding it hugely expensive so I'm not surprised its not viable commercially. Our passive house is going to cost way more to build than it will be worth on the market thereafter. Latest example: We have an integral garage. Garage outside the passiv envelope, hallway inside. Door from garage to hall very nearly impossible to source. You can buy any number of FD30 rated fire doors for a few hundred quid as required by BC in that location. You can buy quite a few doors adequately rated for thermal efficiency and airtightness and they cost low thousands. But try to find a door that covers both angles and that's a tad harder. After a 6 month search I've found two companies who will make me one. One for £7k the other £8k. That's a lot of money for one internal door!

You are very unlikely to get a definitive answer. The fire regs are set out as principles and red flags. That has to be interpreted by someone. Different people on different days will give different answers. We had an issue with two rooms that were considered "inner" rooms - ie no escape window. One was upstairs one downstairs. Our architects had come across the problem before and suggested that they had overcome it before by installing a sprinkler system. I really didn't want to do that, but in the absence of a better idea I commissioned a fire specialist to design a "minimal" compliant system. That was put forward but turned down by Building Control - no other feedback. So I went back to the specialist and got him to do a full blown design - much as you might have in a block of flats. That too was turned down by BC - no other feedback. In a fit of pique I suggested just leaving out the walls so that both rooms were effectively just wider bits of the corridor they were on. That was allowed.... on the basis of access to adjacent room's escape windows. So extrapolating that reasoning, the architect put forward the original design but with doors added to the adjacent rooms. That was passed. Another Building Controller on another day would almost certainly have responded differently as evidenced by the acceptance or not of sprinklers. But while frustrating at the time, I feel lucky to have gotten away with a couple of extra doors and not the huge expense and maintenance of the sprinklers. My advice would be just put forward your the next idea hopefully knocking off at least one stated issue each time. Sounds like you're at least getting some useful feedback on why, so keep that conversation going ...

Not helping your question I'm afraid, but I have one of my own for you. We would have liked a wood burner in our Passive std house. I never considered the issue of the flue and combustibles...we canned it on the need for airflow to the fire. Is the MVHR capable of supplying enough air to meet the fire regs? Last time we fitted a woodburner we had to have an enormous air brick put into the lounge wall to get the installation signed off - not really on in PH!

Interesting - actually taking action against "cartel" like activity. On the other hand, the further I've gotten into self build, I simply don't understand how building houses is a viable business even at their inflated prices. On our last one (sold mid 2025) we broke even if you ignore 10 years of inflation and all the free labour - so a massive loss of wealth in reality - glass half empty ; or we lived in luxury rent free for a decade - glass half full? The current one is shaping up much worse. Looking like it will cost approx 150% of its market value to build despite me doing everything for "free" post water tight shell. Doesn't bother us as we do it for ourselves and have exactly what we want (which is the entire point of doing it) - but we have realised some understanding of why new builds are thrown together with appalling quality when you see how cheap they need to sell them vs the costs of build and materials.

No sure how relevant as I think it will be material dependent, but FWIW: I don't think you'll want 30-40mm on top. We had a long circular drive and parking areas all on slopes. I used 50mm plastic gravel grid trays. Finish material was 20mm black basalt that I shipped in in 16 ton loads. It worked best with the absolute minimum (ie just one stone where possible) above the trays - just enough so that the trays disappeared from sight. Any more and grip on the slopes was lost and the spinning wheels could break up the partitions in the trays beneath. But with minimal coverage, much less likely to slip (except the courier company delivery vans obviously as they have their max launch control permanently engaged). The basalt was ideal being very hard and grippy. Where we are now (while flat) has a light cotswold stone gravel that's really not suitable - over time (needs work annually) it crushes to powder. Don't know where your proposed riverbed gravel fits on the hardness spectrum.