jack

Just the kind of person we love to see. Welcome! When does the next build start?

It wouldn't be relevant to the architect that I could get it built for half the cost, because their way of estimating their charges is nothing to do with actual build costs. I suspect it's as simple as the estimated floorspace multiplied by a rough number representing typical build costs to the standard initially suggested by the client. It's just a massively easier way of coming up with a number than working it all out from scratch every time. I'm sure @Sensus can explain how far off I am with that assumption. I'm surprised no-one would agree to just do the design. I get the impression it's pretty rare down here for the architect to be involved all the way through unless it's a pretty special job. Could well be wrong about that though.

We spoke to 7 or 8 architects, and not one of them wanted to charge based on what the final bill actually was. How could they even know that unless they were involved beyond planning? I suspect we have hundreds of invoices from our build. Will the architect really want to go through those to figure out how much we spent? If I decided to do £20k worth of work myself or with the help of a mate in the trade, how are they going to value that? And why should the fact that I change my mind later in the build and decide to install a £100k kitchen instead of a £5k kitchen have anything to do with the architect unless they're actively involved at that stage? Surely if they're only taking the job as far as planning (which I suspect is as far as most people on this forum who uses an architect will go) the architect's final bill will already have been paid long before work even commences onsite? Indeed, I asked the first two or three about why they used the percentage of estimated costs approach. They all said that it was just the easiest way of doing things. A couple expressly gave the kitchen example, and said that the reason they'd expect a higher fee if they were involved with the design and installation of an expensive kitchen is that more expensive kitchens usually result in more management on their part (more appliances, higher expectation on finishes, more lighting and electrics to consider etc). But they all said that if they weren't managing the build at that point, they didn't see why they should expect more money just because we decided to splurge on a kitchen. Maybe we had an unusual experience, but I'm very surprised at these comments!

Is that usual? None of the architects we spoke to require a QS to price the build. They nominally used a percentage, but it was based on an informal build cost estimate, usually agreed in advance (especially where the architect isn't involved beyond the design stages). The estimate is at least partly based on the fact that you'll have given the architect your budget in advance anyway, but will necessarily be hugely rough given how hard it is to do a real estimate anyway.

No. All rooms to the south and west have some form of overhang or shading via trees, so it isn't really necessary. Also, with many of the rooms we've decided we like the effect of the blinds being down but 70-80% open. Nearly all the blinds are programmed to come down at sunset. Many of the downstairs ones are programmed to open or partly rotate first thing in the morning. The rest (eg, bedrooms) we operate manually as needed. Amazing, isn't it? As a company they have a few flaws (their GBP pricing model drives me mental), and the cost of their proprietary products is at times silly. But if you have any sort of technical or programming background their block-based programming interface is awesome. Have you looked at the Loxone google groups mailing list? Two places: the wire guide holes and the edges. I don't know whether there was an element of safety built into the measurements, or an allowance needs to be built in to allow installation, but on most windows there's at least 20mm lateral allowance. In some cases it's 25+mm. That means you have a total of around half an inch gap both sides, on average. I personally can't see why such a big gap is needed, but at the time they were installed there were so many other issues that this particular one didn't seem that important.

I believe these are the blinds that we have (although under a different brand name). One thing I will say is that they definitely don't block out 100% of the light. We didn't allow for internal window coverings and really felt it with summer's early sunrises. You also need to think about how you're going to control them. Ours are integrated with our home automation system. If anyone wants more info, let me know.

Only if I were doing a flat roof. I'd be happier with the same build up in a pitched roof. The other possibility (for a cellulose cold roof) would have been to carefully detail an internal vapour-tight layer rather than relying on a breathable structure with ventilated head space. I'm assuming, perhaps a little histrionically, that something will go wrong in 10 or 20 years and we'll need to take serious steps to rectify. Hopefully it won't come to that. If I had my time again I probably would have found a way to avoid the flat roof entirely. Hope that helps but let me know if you need more info.

I think the smart bit is the brackets for the verticals. The "hanging tile" cladding could be anything that you can attach to the vertical members or to counterbattens.

Seems a smart system. Any idea on pricing?

Worth a look at the old ebuild SIPS subforum: http://www.ebuild.co.uk/forum/221-structural-insulated-panels-sips/ Look back over at least the top 6 or 8 threads. If you see anything of interest, make a copy - who knows how long ebuild will remain up!

Loving the re-use element to all this. Well done you!

This year, I will mostly be buildin' moi 'house!

You seriously have no idea!

It keeps getting worse. A house that stays over 25 degrees for fully 10% of the entire year is crazy! Worse, it'll typically be the bedrooms that are warmest. To be fair, I don't think many PH consultants, or even the PH Institute themselves, would recommend designing to just the "acceptable" range if it's avoidable. 10% really is a minimum standard, and you'd hope that anyone with basic experience and training would encourage people to get as close to the excellent range as possible.

Banging tune! Video's not bad either

10%? It's worse than I remembered! Given that there's very little chance of overheating for most of the year, this suggests that maybe 20-50% of the days in the hottest part of summer will result in temps above 25 degrees. I don't think that's acceptable at all. One thing I do wish we'd factored in is insect screens, at least in bedroom windows. That way we could leave them open all night in summer to maximise purging of hot air without letting mosquitoes in.

It's been ages since I looked at this, but from memory one of the sheets has an overheating factor, which is the amount of time (as a percentage of days? Not sure) the house will be above a target temp. You can set that temperature as well. From memory, the default setting aren't very conservative - something like 24 or 25 degrees for 5% of the days each year. That's actually quite hot in a Passivhaus, and quite a lot of days. I seem to recall reading that you should reduce the temp setting and do what you need to do to bring the 5% down to 1-2%.

We did the same, although bear in mind that they only come in one or two standard sizes. If you have a higher than usual first floor you may need to make some sort of extension.

Hey, size isn't everything.

I think it's fair to say that this thread has been a lively experience for all. To summarise: 1. Bit of an impasse reached on the "Passivhaus (and current airtight + MVHR approach in particular) = problems" question. Personally I'd like to see some real hard data one way or the other. All of the research I read before making my own decision was very positive, but we do have a different winter climate in the UK compared to that in the countries where most of the research was done. 2. Planning is a bit of a mess and most people would like to see some changes one way or the other. If people want to continue the planning conversation, may I suggest that they start a new topic in the relevant area? If anyone thinks there's still useful discussion to be had on the Passivhaus air quality question given where we got to in this thread, I suggest starting a new topic with a new focus. I can link this thread to it if that happens, so the information remains linked.

I wouldn't have believed this was possible until one of our friends' young teenagers someone how managed to turn the boiling water tap on to wash his hands! No serious damage done but a fair bit of shock for all concerned. Personally I'm amazed he got it going at all (there's a knack), and also a bit puzzled about why he used this small tap off to the side rather than the stonking big one in the middle!

We did this. Our ASHP is on the north wall of our attached garage, which is on 300mm insulation (no idea why - easier to work to the same level across the site I guess). I made two trenches in the middle layer (of three) by cutting some EPS pieces. I then foamed in some 60mm (from memory) polypropylene pipe. The next layer of EPS held it all in place. We then got some 28mm (I think) pushfit barrier pipe and some long rolls of stick-on 3 or 4mm thick nitrile insulation tape. This was just wide enough that two parallel runs covered the outside of the barrier pipe. I greased it up with a little washing detergent and it pulled straight through the duct. There seems to be very little temp drop over the 8 or 9 metres the pipe travels to the plant room, even when running at 55 deg C. The temperature at the top of the UVC gets to exactly 55 deg C every morning throughout winter. The one thing that worried me a little was that we had to go through the ring beam. I used some foil-covered rockwool sleeves wrapped in DPC plastic to protect the pipe and insulate it from the ringbeam. Seems fine. The area where it comes through is one of the lowest stress points of the house, and the heat going through the pipes every day, at least in winter, should avoid condensation (I hope!)

On cost grounds? Must say, I wasn't 100% sure when we chose to install one, and now I wouldn't be without it. Forgot to do veggies for kids' tea? Frozen peas, boiling water tap, done faster than even the microwave can manage! Not to mention the ability to make a cup of tea in about 20 seconds start to finish, which comes in handy if you watch a lot of BBC (no ads).

Yes, should have been clearer. The question was "is it essential?". The strict answer is "no". If the question is "should you do it?", then the answer is "yes". I would have had a more relaxed time if I'd gotten around to doing it before the slab was poured. As it happened, it was the follow-on trades that I should have worried about! Edited to add: So what do you do as, say, the third of four lined-up concrete trucks starts dumping its load into your slab and you suddenly note a drop in pressure? What could realistically you do at this point? Stop the pour? Start digging around in the stuff already poured to look for the leak? Genuine question - sounds like a very unpleasant position to be in!

Yes, I read that too - several weeks after our slab had already been poured!!! I believe one of the major reasons this is done is to stop the pipes floating up when the slab is poured. If they're tied down properly, this shouldn't be an issue. So, "essential"? Not necessarily. Disclaimer: I know nothing.