Health risks associated with passive houses

[Nickfromwales]

11 hours ago, Sensus said:

 

Cue thread about overheating and inadequate management of solar gain...

http://www.ebuild.co.uk/topic/12249-deadly-summer-overheating/page__fromsearch__1

[NSS]

8 hours ago, tonyshouse said:

Go for good air tightness or you will let allergens in!

 

go for the good filters that you are planning, there will be a cost, change regularly.

 

go for a good air handler, Genvex and a good designer, Europeans seem better than here though there is a very good company here.

Have gone with Paul Novus 300 for the MVHR as they appear to offer the best filtering levels. Many seem only to supply filters that would barely stop a whole flower from passing through, never mind pollen and other particulates!

[NSS]

7 hours ago, Mikey_1980 said:

 

Hi NSS, my Wife like yours suffers from bronchiectasis, and has been on long courses of Antiobiotics many times over the past 4 years since it was diagnosed and although building our house wasn't a driver for a better standard of health we made sure that we could get a good flow of air via the MVHR to hopefully try and alleivate the chances of recuring chest infections.  The strange thing that we have found is that moving from our old house and into a draughty cold caravan and then into the new house, so far in the past 12 months their has not been one recurrence yet, whereas before every 6-9 months she would be on a course of antibiotics for 1-3 months or longer.  Our fingers are crossed that maybe there was something in the old house triggering it, or just the fact that quality of air in our new house is better but something had definitely improved the situation.

Hi Mikey, sorry to hear your wife has a similar issue. Sadly my wife's condition has already progressed to the point where she has to nebulise antibiotics twice daily for the rest of her life (and still ended up in hospital with pneumonia and pleurisy again earlier this year). She's hoping the new house may help sufficiently to at least be able to reduce her dependence on antibiotics, asthma inhalers, antihistamines and steroids. Time will tell I guess.

[NSS]

7 hours ago, Sensus said:

There are alternative solutions apart from MVHR, of course... and airtightness doesn't let allergens in if the air is only leaking out (PIV and MIV).

 

Personally, if it were so critical that the house should be livable without ever opening the windows, I'd be very seriously thinking about air conditioning: the best you will ever achieve from MVHR is to draw air in at external ambient temperature and only add a little to it with solar gain and occupant heat input. If it's 28 degrees and humid outside, that's still going to be a pretty miserable environment to be in.

 

If you have no alternative, then at least incorporate as much thermal mass as you can, to 'damp' temperature fluctuations to as close as possible to the 24 hour average.

We looked into AirCon but decided against it (partly on cost). The Paul MVHR has an option to add a cooling function and we have also included a Panasonic air rad in our bedroom so we can provide localised heating or cooling as necessary.

[tonyshouse]

In a well insulated house when the outside temperatures is high the indoor temperatures remain comfortable so long as solar gain is cut out by using external shading or shutters.

[NSS]

1 minute ago, tonyshouse said:

In a well insulated house when the outside temperatures ate high the indoor temperatures remain comfortable so long as solar gain is cut out by using external shading or shutters.

Hi Tony, as mentioned we're hoping the electrochromic glazing will control solar gain.

[Ferdinand]

On 08/10/2016 at 13:09, Sensus said:

 

That's because you're forgetting Rule 2 of Plot Finding: most plots never reach the open market.

 

Rule 1, incidentally, is that any plot that does find its way to the open market is, by definition, grossly overpriced.

 

 

Thinking about this particular point by @Sensus.

 

Slight apples and oranges here.

 

Of course any plot that does reach the open market will have at least Outlne PP, and at least part of that extra price is due to the reduced risk.

 

While any Plot that is found for me will not have that priced in, subject to a "get me PP" condition, and I will have to pay Mr Sensus some significant amount of £££ plus potentially lunch for his services plus someone more £££ t o get me planning, and a barber to dye my new grey hairs the correct colour  .

 

The plot which I posted on the thread went for 22% or so below asking, which strikes me as relatively usual.

 

Ferdinand

Edited October 10, 2016 by Ferdinand

[Trw144]

8 hours ago, Mikey_1980 said:

 

Hi NSS, my Wife like yours suffers from bronchiectasis, and has been on long courses of Antiobiotics many times over the past 4 years since it was diagnosed and although building our house wasn't a driver for a better standard of health we made sure that we could get a good flow of air via the MVHR to hopefully try and alleivate the chances of recuring chest infections.  The strange thing that we have found is that moving from our old house and into a draughty cold caravan and then into the new house, so far in the past 12 months their has not been one recurrence yet, whereas before every 6-9 months she would be on a course of antibiotics for 1-3 months or longer.  Our fingers are crossed that maybe there was something in the old house triggering it, or just the fact that quality of air in our new house is better but something had definitely improved the situation.

 

So pleased to hear this, my daughter has a chest condition and I m hoping the new house will be the best possible environment for her to minimise risks. Have also opted for uv sterilisers on the water and pollen filters in the mvhr.

[Ferdinand]

1 hour ago, Sensus said:

 

True enough on most open market plots having Outline PP (though not all - I've just been looking at this one in Boston which is a fine example of Rule 1 in action! ).

 

But when we negotiate land purchase off the open market, it's frequently (unless planning is a dead cert) an offer 'subject to planning', so it's not the risk you might think. Certainly, there are potentially abortive costs for the plotfinding services and Planning application, but those are never anywhere close to the many £tens of thousands you'd be saving against buying a plot on the open market, even if that open market plot exists.

 

For what it's worth, my own practice pretty much operates the plotfinding service as a loss-leader, on the assumption that by the time we've found you a plot, you're sufficiently impressed with our expertise that you stick with us for the rest of the design process. Plus it quite frequently throws up a number of other viable plots, which we can then promote to other contacts.

 

My hair has been grey for years now, so I've nothing left to lose...

 

I forgot about "subject to Planning".

 

Yep on that Boston one.

 

Worth 15-20k once it has PP and the tenant has gone? Maybe?

Edited October 10, 2016 by Ferdinand

[Stones]

On 10/9/2016 at 19:55, Sensus said:

 

Also, the reality is that even those of us who understand (most of) it - and I count myself as guilty as anyone in this respect - can't afford the time to assess it properly. It's simply not commercially viable.A lot of design with regard to stuff like this - and thermal mass/solar gain - is done by gut instinct and rule of thumb, because to do it properly is so time-consuming that no client is prepared to pay for it.

 

And please, nobody quote software tools like PassivHaus or SAP, because they're so crude and simplistic that they're next to worthless!

 

 

Just to pick up on this point, isn't the fact that it isn't commercially viable for developers to individually model each plot (for arguements sake lets say on a 500 home site) as responsible for some the problems being reported / encountered as the higher standards of insulation and airtightness themselves?  

 

A large development may only have a handful of designs, which are then placed at completely different orientations around the site. While one design may be perfect / optimum in one location, the converse may be true for another location and significant problems (solar gain being the obvious one) ensue. 

 

 

 

[SteamyTea]

8 hours ago, Sensus said:

No, is the short answer.

I tend to agree with this (not that I have on site experience of the trade).

My house is one of the first 6 of their type built in the SW.  They showed that there was not any problems with the design, then built thousands of them (they are ugly grey boxes, but I sit in it an look out, not the other way around).

 

I think what the volume builders suffer from is lack of on site build quality control.  Details like fitting insulation correctly, plumbing and wiring not to the drawing, fitting MVHR badly, and the big one, fitting windows and doors.

The last one may benefit from better detail design to make installation easier, but probably the biggest benefit would be had from not having a pile of 'stuff' not sitting around getting covered in crap.  It is hard to motivate a person to do a good job when you supply them with substandard goods to start with.

 

So this comes down to training and management.  Two things that the UK seems to have forgotten how to do.

I worked in education for a while.  I lectured in IT, but the courses were tailored to cover everything from first year plumbers, to Ma courses in Journalism.  So I had an interesting spread of people, including a couple of Architects.  I would often read the press, and hear on the radio, that the education system was not turning out students that where fit for the workplace.  Not once in that time did a company come to me (apart from the NHS and Network Rail who had large budgets to dispose of) willing to pay for a tailored course.  I wish they had, as I could have easily done a basic Mathematics and Science course that would allow ordinary people to appreciate what highly educated people where talking about (most science is pretty basic really).

One of the problems is, I think (personal experience and a lot of prejudice), that you get some people that will justify a wrong decision and defend it to the end.  If that person happens to be articulate (think Boris Johnson), many people are taken in.  This is why the real sciences use data.  Without it, or if it is not disseminated, society really cannot move on and probably goes backwards in some situations.

[Stones]

19 hours ago, Sensus said:

 

No, is the short answer.

 

I was going to write a more detailed explanation of why, with supporting examples. But it's late, and I know that most self-builders wouldn't believe me, anyway, so there's probably no point!

 

Medium length answer is that developers do routinely model all variations of their standard housetypes (ie all solar orientations; all configurations of detached/semi-detached/terrace). They also run alternative models for different ventilation, insulation and heating system scenarios to maximise efficiency and for compliance with different design standards. The additional cost of running these variations, once you've got the basic model set up, is relatively trivial in the context of developer budgets.

 

 

Standard housetypes for the major developers are actually a LOT more thoroughly designed and developed than almost all self-builds (to an extent you might find difficult to believe), for the simple reason that the design costs of the former can be commercially justified and amortised over a large number of units, whereas the typical self build is usually a one-off prototype built to a very tight budget.

 

 

 

 

 

Very interesting.  My perception has always been the reverse, generally influenced as it has been by the experiences of friends who have bought or lived in large developer built houses, but that is perhaps more to do with the issues highlighted by Steamy.

 

When you say house types are a lot more thoroughly designed and developed, in what context do you mean?  I'm guessing from your previous comments about developer build costs that the focus of all that technical design work is to be able to build these standard units at the lowest possible cost (far lower than a self builder could achieve).  

 

 

 

 

 

[TerryE]

@Sensus,  until JSH returns (hopefully)  I've been missing  informed  debate so welcome  ?.   And taking the thread in that vein, let me gently push back on few points. 

 

First,  I don't assume that all of the moisture comes in with air exchange.  This is clearly not the case,  so why would I come to this conclusion?  However with a house of 500m³ occupancy volume at 0.6 ACH and three human (no horses, etc.) occupants,  it  is by far the largest component. That's assuming of course a modern passive spec house with decent VCL etc.

 

Can  you explain the wild (and entirely inaccurate) assumption, because you've lost me on that one?  I don't dispute your anecdotal  experience,  but I do dispute how relevant it is to a properly designed and operated passive house with MVHR.

 

I agree that mould growth is a harbinger that shouldn't  be ignored.   We constantly see the symptoms of this on the windows of our current farmhouse,   but it is over 300 years old with wooden windows and partly 20-30 year-old double glazing units, not a modern spec'ed house with triple glazed units with a U-value < 0.7.  If @JSHarris @jack @Declan52 or any of the other members with essentially the same build spec report issues, then I might start to question my understanding  of the physics here. 

 

But in the meantime I will keep to my views. 

[Construction Channel]

FWIW I think you've all done very well for staying civil this long

 

[Declan52]

I am by no means clued up in the whole science behind mould but the vast majority of it in houses is caused by condensation. So you get damp air that settles on a cold spot on a wall where it condenses and eventually forms the mould. Every house will have damp air from cooking, breathing etc so what makes most of our self builds apart from the developer option is the use and maintained use of mhrv. By having the air constantly changed and clean air coming in the humidity can't get high enough to cause the issue. 

Same goes for cold spots as most of us have spent more time and effort detailing the insulation levels so you are down to either none or very few cold spots. Compare this to the litany of reports like the guy Luke on twitter who bought from Taylor wimpey where his whole house was a cold spot due to no insulation at all in the cavity or attic and it's easy to see why you get mould in some new builds. 

I took a complete shot the dark 3 years ago when I installed mhrv as I knew no one who had it and never seen it installed in any house we ever built, grand designs and the build shows where all I seen. From the day we moved we have never had any  condensation on any window even when house was drying out. The air is always clean and fresh and from someone who has sinus problems in the past it has helped me. So in essence by building it right and using mhrv and maintaining the system mould should be a non runner. 

 

[jack]

40 minutes ago, Declan52 said:

and from someone who has sinus problems in the past it has helped me. 

 

Glad to hear this isn't just my experience.

 

Of course, if there are issues, they're likely to be slower to appear than in something like the Taylor Wimpey house you're referring to.  Perhaps we should all compare notes in 3-5 years when we have a few seasons under our belts!

[oldkettle]

2 hours ago, Stones said:

Very interesting.  My perception has always been the reverse, generally influenced as it has been by the experiences of friends who have bought or lived in large developer built houses

 

Completely agree, again, after visiting friends who bought new from big developers. 

 

@Sensus, please look at these

http://www.rightmove.co.uk/new-homes-for-sale/property-60637082.html - how do you like bedroom 2 ?

http://www.rightmove.co.uk/new-homes-for-sale/property-44469513.html - same here. I can easily imagine one being hit by the door when looking inside the wardrobe

https://www.taylorwimpey.co.uk/find-your-home/england/hampshire/eastleigh/bakers-quarter/plot-058-the-kentdale this one is just brilliant. Of all the bedrooms only one is rectangle, the rest have extra angles that make them "interesting". Look at the master bedroom, you can only get a 2.5m wardrobe in there, would you say it is enough? Positions of windows and doors make usage of 3 out of 4 bedrooms extremely limited.

 

I am not an architect but I looked at many houses like these and I find this kind of layout ... well, bad, inconvenient for people who are unfortunate enough to live there. And I would be surprised if you said these were well designed. 

[Declan52]

I was in my new build 2 years at the start of this month so don't have far to go!!

I notice it as my last joint was very humid my nose was always congested which eventually ended up with a headache  and same goes with  itchy eyes.

[Declan52]

They are well designed as in they use the least amount of the cheapest materials possible to build a house. And they look really good in the brochure but after living in them for a few months and having tried your best to rearrange your beds and furniture you realise that no matter what way you do it it just doesn't work. That is unless you buy the cut down beds and furniture the show house had.

[IanR]

36 minutes ago, Sensus said:

I'd point out that it hardly matters if the incoming air has a RH of 60%, if it stays at 60%...

 

You may wish to reconsider this statement.

[oldkettle]

46 minutes ago, Sensus said:

I don't think the houses you're pointing out are actually too bad, in terms of layout design, and given overall spatial/size constraints. If those are the worst you can come up with, then I think it reflects the industry fairly well.

 

 

I was not trying to prove that every self-build is better (in terms of quality, design etc) than mass build. I was reacting to your statement that mass build is "thoroughly designed and developed". Well, I am sorry, just can't treat those examples as such. And no, it was not the worst I could find, it was the second in the queue here

https://www.taylorwimpey.co.uk/find-your-home/england/hampshire

There are more badly designed houses then well designed ones, so I can just keep going

https://www.taylorwimpey.co.uk/find-your-home/england/hampshire/andover/the-chariots/parcel-b---plot-011---the-buckingham - BTW, this one is just... WOW - the 2 bedrooms on the left side! And just imagine that it could have been an excellent 4 bed if they did not split them.

https://www.taylorwimpey.co.uk/find-your-home/england/hampshire/andover/the-chariots/parcel-b---plot-006---the-stanton

https://www.taylorwimpey.co.uk/find-your-home/england/hampshire/andover/the-chariots/parcel-b---plot-061---the-langdale

The first detached one in Suffolk

https://www.taylorwimpey.co.uk/find-your-home/england/suffolk/kirton/violet-gardens/plot-37-the-kentwell - check the main bedroom on the right with massive claimed size and yet no real space for a proper bed and a wardrobe at the same time. I mean any bed with the headrest will force people to squeeze between it and the wardrobes.

 

Note, these are all from expensive part of the range (for the area), large detached houses. And even those are hideous on the inside. 

 

And then you say they care. Well, I do believe they care about not having complaints, so warranty part - yes. As for the floor plans... people have no choice but to buy from them because there is not nearly enough competition in the new home market. So most will have to take what's there - as bad as it is. I am sure you know that architects themselves say sizes are inadequate https://www.architecture.com/RIBA/Contactus/NewsAndPress/PressReleases/2015/Over50ofnew-buildhomesaretoosmallforfamilies.aspx This just scratches the surface. Adding 5m2 of footprint to every house costs peanuts to a big developer. It may even save them money by allowing simpler layouts. And do they do it?

Oh, who in their right mind will forfeit extra profits to make customers this bit happier? By the time the average person may come back for another house (does it even happen with more then a few percent of population?) management is long gone.
 

@Sensus, I want to make one thing clear. I know I am throwing a lot at you in these posts and it is not too well organised. I have absolutely nothing against you personally. You are here to share your expertise and this is great. Hell, I have nothing against every individual big house builder. But I dislike them as a whole, as part of the system, passionately. The way housing market is functioning in this country really gets on my nerves.

 

[K78]

A lot of passive aggression on this site as well as passive houses.

 

Sensus is making some valid points and obviously has more experience than most on here. 

 

Its good to look at positive and negative aspects of passive houses. They're not perfect. 

[Crofter]

 

This is a really interesting discussion with a lot of experience on both sides. Hence plenty of anecdotes to back up points either way- which is natural, given the huge number of houses that are out there.

 

It seems to me that passive houses which are either built or specced wrongly are entirely possible, but perhaps the biggest danger is that the occupants do not understand the house and equipment like MVHR. However, it also seems likely to me that such people are unlikely to be on this forum and participating in this discussion, so what we do have is people who have thoroughly researched their projects and feel defensive of the concept as a whole.

[Barney12]

10 minutes ago, Sensus said:

 

 

The product of big developers is driven very much by the market; if the market really wanted bigger, or more energy efficient, or more contemporary design, or whatever, then you can be assured that that's what the big developers would deliver.

 

And that is the absolute nail on the proverbial head! Modern housing is now very much in the realms of "consumer purchasing". Developers build what people want to buy. Full stop.

 

To quote the HBF 2016 survey:

 

"In terms of the design of their new home, 92% of buyers were satisfied with the internal design of their new home and 86% were satisfied with the design externally."

 

Yes, legislation can help shape energy efficiency, design, house sizes et all but ironically if the government or the big developers do too much of that then the accusations of nanny state would fly in.

 

As @Crofter has said this forum is far from being an accurate cross section of the wider community. Anyway I don't want to be part of the 'common herd', I aspire to being just a little eccentric

[oldkettle]

8 minutes ago, Sensus said:

 

I tend to take a much more 'live and let live' attitude, I must admit.

 

I now choose - as an entirely free and conscious personal lifestyle decision - to live in a flat that is probably smaller than would be allowed under the NSS. Should I, in your opinion, be prevented from doing so? For my own good, perhaps?

 

The 'system' doesn't stop you buying or building a bigger house, if that's what you want to do. But the market has voted with its wallet - even for existing housing stock, there's a dramatic fall-off in values per square foot, over a certain level, which tells you that the market doesn't want the extra space enough to be willing to put its money where its mouth is - so I think you have to respect that, even if it doesn't conform to your personal preference or politics?

 

 

1) Since my posts do appear aggressive I apologise. No harm intended, as I already said.

2) I certainly agree with "live and let live" approach

3) I am also very much against government intervention in most areas where it somehow believes - likely because a lot of people do - it has to act.

4) Which means that the answer to your rhetorical question :-) is no, I have and want to have zero saying in how other people choose to live.

5) I completely disagree that having a paper size of >X makes a house somehow good. Houses that I linked to may be large but the layouts are inadequate. And sorry, there is no way a survey by vested interest organisation is going to change this for me. I choose to believe my eyes.
6) I also don't see much point in "price per m2" comparisons - it should be cheaper after a certain size because it is clearly cheaper to build (per m2).

7) I would be curious to see the result of a survey asking "would you like 20% more internal space for 5% more money" :-)

 

I just noticed that most points that I was trying to make (and some of yours i.e. density requirements) are already here.

https://www.architecture.com/Files/RIBAHoldings/PolicyAndInternationalRelations/Policy/Housing/ImprovingHousingQuality.pdf So I am not entirely delusional.

 

Lastly, with regards to the original point.

From what I can see - and as usual, please do correct me if I am wrong - the only problems related to PH seem to be

a) pure air quality (that sometimes manifests itself as mould etc)

b) overheating

i.e. in both cases not enough ventilation. Would you say this is fair? Any other major issues like houses falling apart or fire safety?