Health risks associated with passive houses

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@Sensusnow they are what I'd fair statements, the average RH in the UK is high,  though where I live is below average.  20°C is far above the average delta. However,  if I take your thesis that any dry surface in contact with air with an RH of 70% say has a material risk of mould growth then we'd like have mould-ridden walls and houses.   I am still at a loss as to why passive houses with correctly operated MVHR represent a greater risk than stock housing: most surface are within a degree or so of room ambient; air circulation is better and sources of moisture such as kitchens and wetrooms directly exhausted and RH extremes reduced because of my previous arguments.  Every member here who lives in such a house says they are healthier and mould effectively eliminated.


So what is the risk?  Is you next thesis that children shouldn't be vaccinated? 


If I find any material issue with mould in my new house then I'll post some pictures back here and an apolopy

Edited by TerryE

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Don't leave.

I am interested in this as to a certain extend I agree that the recommended air changes are low.  What do you think we should be aiming for?

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11 hours ago, Ferdinand said:


I think those statements are not very meaningful. What do you *mean*?


Who has a right to a house and what do they have a right to?


Do I get a house if I just came in from Poland? What about if I am 21 and pregnant or single with a child? What about if my GF is 21 and pregnant and we split up? And so on.


Without precise policies we can't work out the impact, and it is just a feelgood handwaving competition,


And are you happy with the consequences of such a "just do it" policy? And how will you ensure decent house that people want to live in? How do you ensure they are efficiently built?


What happens if the govt CPO your house and build a small block of flats on it? You won't get much chance because under your suggestion the people who build or commission it it will be the same people who give themselves Planning Permission.


Still happy?


That is the massive conflict of interest that exists in such circs and is why I am vigorously opposed to substantial local political control over housebuilding / management - Housing Associations are OK, ALMOs sometimes, Council Estates under direct political control: No.


I'll get on to the numbers implied and the problems of gormless politicians later, maybe. (Taster: Our Housing Cabinet member here's main claim to fame is appearing in a photo next to Ed Milliband wearing a "dance on Thatcher's Grave" teeshirt.)





Immigrants and benefits arguments? Have I walked into a UKIP pub by accidents. With rights come responsibilities. The government of the last however many decades have set up this cluster**** housing situation. Where is the supply of houses people want to live in to suit their circumstances close to their work that haven't been hoovered up by the luckiest generation ever to who lived wo still aren't content. 


There should be a much better framework in place to build more in the places they need building not self build dreams in rural NI or the far reaches of Scotland. The govt doesn't need to build just let others build. It sucks the life out of me via income taxes rather than wealth taxes if can bloody well make it easier for me to make a living without the difficulty of living under an (Un)assured Shorthold Tenancy.


More planning permission in more places, fewer bungs to builders, fewer bungs to land holding parasites, better rights for tenants.

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On 12 October 2016 at 21:40, Sensus said:



But (on topic) isn't that even more true of a self-built PassivHaus? If you've just spunked your life's earnings plus 5 years of your life on a pile of OSB and fibreglass quilt, how likely are you to admit even to yourself that maybe it wasn't the perfect solution that someone convinced you it was at the outset?



Morally and idealistically, I'm right with you (I'm quite left-wing, when you scratch the surface). Pragmatically, it ain't gonna happen in the foreseeable future: the public sector is bankrupt and there's no way of funding it.   


At the current rate of housing construction, and even assuming no growth in population (which is another thing that ain't gonna happen), it will take us 250 years to replace all our existing housing stock, so we're going to be stuck with draughty, cold, mould-ridden houses for quite a bit yet. And that's assuming the stuff we're putting up today will last 250 years and not require replacing itself, which is is a third thing that ain't gonna happen.


Sorry, Barney... I'm not doing anything to lighten the mood much, am I?!


First bit, old bean, is the logical fallacy of false equivalence. Of course a Passivista (and I am not one) will think they're correct, they'll most likely spent a lot of time convincing themselves of it. Joe Schmuck doing it because of cultural brainwashing that house prices always go up is not the same.


Second bit, of course you are socialist, you support the housing/building industry. Where do the subsidies stop? Planning permission forcing price up, help to buy subsidies to builders, tax breaks (until recently) and rent subsidies to landlords. I'm not sure there are many more state interfered industries in the country.

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12 hours ago, SteamyTea said:


Addressing the 'small houses' issue.

I live in a small house, 4m by 8m.  It has a corridor for a living room, where the stairs are.  The parking area is at the back, steps up to the front door.

Upstairs the bathroom is wedged between the two bedrooms, one an OK size, the other tiny.

Now someone 'designed' this.  Technically it is well insulated, airtightness seems reasonable and it costs next to nothing to run (why I bought it as I was a student at the time and it is close to the college).

So imaging that you park your car, come in the back door, where is the light switch, oh, other side of the room (kitchen).

I have an ordinary sofa, nothing special, but it is too long to put across the living room, it almost hits the stairs, put it along the living room wall and you then have an even narrower corridor.

You can put the TV under the stairs, it was 'designed this way' as the TV aerial point is there, but as it was 'designed' before flat screen where in existence, it would have 'stuck out a bit', right by the kitchen door.

Now when I live on my own, I can cope with this, but when I had a lodger, the layout just don't work, it really does not.  There is no way to get from the bathroom/bedrooms without passing though the corridor/living room.

Could it have been improved, yes, if it had been made a bit wider, then the stairs could have been turned 90°.  This would have acted as a separator between the front and the back rooms, making rooms truely individual rather than just a corridor.  There was enough room on the plot (of 6 houses) to do this.


And that is before we get onto the 'social' side of housing.  Most individuals need some individual space, the larger the family, the more space they need. Men have sheds, women have kitchens, boys have bedrooms, girls bathrooms.  Well it seems that way to me from looking at adverts.

My old neighbours where a family of 4, two teenage boys, mother and father.  They were crammed into 52.5m2 total internal floor area.  This is just not right, but probably not unusual.  It cannot be good for mental health to be crammed into such a tiny space.  This may account for my current neighbours being a family of 3 (7 year old child), single, single, single, single, family of 3 (baby).

Now an 'engineer' or economist, may well say that there is wasted space as there is at least 4 unused bedrooms.  But this does mean that we can have friends to stay without putting them up on the sofa in the corridor.


Having studied Economics (as well as other things), there is a bit of a myth about Supply and Demand.  There are two ways to look at this.  One, the normal methods quoted by 'industry experts', says that if there is a shortage of house, the price will be higher.

The alternative is that if money is cheap, and it is very cheap at the moment, then the price of housing will be higher.

So what have we done in the last 40 years.  We have built more housing (there is no shortage of housing, just the distribution is not always right).

We have allowed women to have there own mortgages since the late 1970's  Hard to believe that they needed a second (male) signatory on the paperwork just 39 years ago.

Then, a decade later we removed double tax relieve, pushing up property values and speculation that took nearly 10 years to recover from.

Then, though financial manipulation the formula to work out affordability was changed from a simple multiply of of mean wage to median household income (this has, in effect, made more money available as not many people earn zero, but a few earn millions).  Coupled to that is the way that banks have changed the method for lending money, they now work on a multiple of total household income, rather than multiple of major income plus minor income.  Again this has increased the money supply to the housing sector.

So take a simple 'old' method of a man earning £10k and the wife earning £5k, with a multiplier of 3.  They could borrow £35k

Now they can borrow £45k.  This extra £10k (28% increase) is just sucked up by increased property prices, nothing to do with the supply and demand of the housing stock (we still have about half the number of houses as people).  There has been no added value anywhere.


So what can be done about it.

First off, everyone that wants to buy a house should work out what they can realistically afford to pay back, (3 times income is pretty good), then, every Saturday morning, spend an hour going to estate agents and point out that their houses are probably at least twice as expensive as needs be, and probably 4 to 5 times as expensive, and would they tell the sellers that.

You will probably get asked to leave the office, but if enough people do it, then the message will get driven home.  This is especially true for first time buyers (and for every first time buyer there is a last time seller).

The other things we can do is to stop thinking that the country has lack of room for housing.  There is plenty of room.  Urbanisation has only used up about 9% of the land area, housing is probably less than half of that, including infrastructure.

So when a farmer wants to sell an acre of crap land for building, let them, it really won't affect your life.  This has to be better than cramming in more and more people into existing towns and cities.  This fixation with 'brown field' must stop.  Turn a few of them green.

I used to live in Buckinghamshire, where my Mother still lives.  It is a nice leafy green place, popular with locals, London commuters and media celebrities. It has a population density of 404people/km2.  Milton Keynes is a good place to live and work (I lived there and worked there once, better than Aylesbury or High Wycombe I found).

Now I live in Cornwall, it has a population density of 150people/km2.  So under half the density.  Most new developments are opposed here because of pointless, uneducated arguments about overcrowding.  We have plenty of space, so much space that we can accommodate 5 million visitors a year, ten times the resident population.  Our infrastructure copes, no one gets hurts, all very pleasant in the summer.

Last week there was a major accident on the A30, closed both ways as the helicopter had to land.  It took me an hour to get the ten miles to work.  It usually takes me 15 minutes.  What it reminded me off was my old commute to Kingston Upon Thames from Aylesbury.  The last ten miles could take an hour.  It was just part of life.  A time to sit back, relax and plan my day.

I cured that problem by leaving earlier and getting to work by 7AM, leaving earlier when I could, only too just over an hour then.  It worked well.

The point of that is that there is no need to fear extra housing, or building larger houses, it does not affect the price, that is affected by income potential and interest rates.  Small housing, at the lower end of the scale, is not good for society as it forces overcrowding and ghettoisation, under out current planning system.  Commuting can be good if done right (we are starting to move to an era of lower emission vehicles).


So if we start to build slightly larger housing, get rid of housing that is single bedroom because of the inherent restrictions, expand our towns and cities less, move people to the countryside, we can probably reduce overall air pollution, and almost certainly remove very high concentrations of it.  This would reduce the need to 'filter out particulates' as much as we need to now, could help rejuvenate rural communities, disperse income and make for a better society.


Not much of that has anything to do with the study of MVHR in Passive Houses.  That is simple to solve, put in a larger unit with larger vents and ductwork.

We really must stop working to minimums.


Steamy, I always thought you were a bit of a <insert Ofcom mild rated profanity), especially over your energy facism but here you've nailed it. 


When a crossover of demographics and soylent green hit your energy radar, I may start to listen :D

Edited by daiking

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No particular politics ... just attempting to interrogate the implications of your proposed Right to Housing wrt the numbers. 


Supply, demand and how to build that supply are relevant. So is demand management but if it is to be a genuine Right to Housing then demand management is mainly moot.


There are two main drivers of the houses you are going to have to build, which are net immigration and household size falling. Others would be for example restrictions on HMOs and the numbers of students living away from home as University attendance has gone from 10% or so to 40% or so.


We need to look at demographics because e.g. more one person households will be adding perhaps 100k-200k+ a year to the demand for some sort of Housing. Do they have a Right to Housing? What sort of Housing? Who decides? 


We need to talk about immigration because the main element of demand for more houses is population increase, and in the period 2000-2015 Uk population is up by around 5m and approx 70-75% (estimate but roughly right ) of that increase is net immigration (I make it about 3.7m net immigration).


This is a report from the Govt on household formation in England published in 2010 looking at the period 2008-2033



Reported in summary by the Beeboids here:



That came up with a number of new households of 6-7 million between 2008 and 2015. Add another million for SNiW. THese numbers were reduced from the previous 2006 report.


Their high projection for immigration was 217k a year. In fact since 2004 to now the average is around 250k, and we may be heading for more like 9-10 million than 8 million new households. Ironically Brexit may help. 


That is an extra 40%, so pro rata 1.4-1.5 million new households in London for example.


And then we need the local authorities who have been trying to build fewer houses than requested by a strong central policy for a decade to pretty much double their allocations, under your proposal for a 'local service'.


How would that work? Would you abolish eg the Planning Inspectorate as an unwelcome central body?


(There is also the question of LPA competence and politics. When we applied for our Housing Estate PP there were councillors on the Planning Committee - this in a DC with a 100k population-  who did not know where the community development boundary was.)


Not trying to go in too hard on you here, but we have had too many years of non-joined up policy ideas.


Since we are slightly of topic too suggest we wrap this up quite soon. I have 2 lofts to insulate this w/e.





Edited by Ferdinand
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For the record my policy mix would involve (on top of current measures):


1 Some planning reform. Simplify.

2 Restart rural development in existing communities.

3 Some ultra high density development e.g. THamesmead as is done elsewhere in the world where space is tight.

4 Policy driven locally but make development to be done by Housing Associations not Local Authorities.

5 Review rental regulation in England which is currently as nutty as the excess stakeholders in the planning process.

6 Develop measures to slow down or reverse falls in houshold sizes. E.g. Half council tax for two pensioners or singles sharing.

7 Some relaxations of green belt.

8 Much stronger regional policy to move activity north and west.


I am not sure how to address the NIMBY problem, which is crippling. Also not sure about the housing target regime. And not sure how to handle a regional policy in SNiW.



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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.

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