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Best 5 Things You Like About Your House?


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#41 jsharris

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Posted 09 April 2016 - 01:17 PM

View PostDavidofMersea, on 09 April 2016 - 12:41 PM, said:

There is a body that measures the air tight performance of your house, and gives you a certificate if they find it is above a certain standard, that is what I was referring to when I said Passive House Status

No they don't, and there is no such thing as "Passive House Status". A house can be a PHI certified Passiv Haus, or it can be an equivalent or lower energy use passive house that has not been certified by the PHI and may or may not use PHI certified components.

The PHI certify on the basis of a whole raft of things that show that the house meets their performance standard, including the use of approved components, but they do not do air leakage tests. UK building regs require air leakage testing (as do many other nations building regs) and all the PHI stipulate is that air leakage should not exceed 0.6 air changes per hour with the house at a pressure differential of 50 Pa relative to the outside air pressure. The PHI require that the house performance is designed and assessed using their method, the Passiv Haus Planning Package, and that includes a great many things other than air leakage. It's like a more complex version of the UK building regs Standard Assessment Procedure (see here: https://www.gov.uk/g...sment-procedure ) that has to be used for new builds.


View PostDavidofMersea, on 09 April 2016 - 12:45 PM, said:

Of course you can make your house smaller and have fewer and smaller windows and doors, but that is not a sensible comparison with other houses and air tightness

Making a house smaller can make it harder to reduce the energy consumption to passive house levels. Larger houses can comply more easily, because heat loss for a large house tends to be dominated by ventilation heat loss, not fabric heat loss.

If you build a large house to UK building regs minimum fabric performance standards (the U values for the structure, doors, windows etc) then you could possibly still achieve a passive house performance level with good airtightness and an efficient heat recovery ventilation system.

Edited by jsharris, 09 April 2016 - 01:18 PM.


#42 mike2016

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Posted 09 April 2016 - 01:57 PM

Well,

From my own perspective these are the top 5 things I'm looking forward to for the house I hope to build:
  • Open Plan living area / kitchen to hang out / eat / cook in
  • Comfortably warm all year around (Be it near Passive or better)
  • The chance to move out of the various bedrooms I've been renting for the last two decades into an entire house I can change, adapt, furnish and colour as I want to...
  • Minimize my impact on the environment through house design, construction and living stages
  • The chance to test new ideas / technologies / home improvements with my own personal petri dish of four walls, foundation and a roof
As long as I don't burn it down by accident on the day I move in.....!!

Mike

#43 joe90

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Posted 09 April 2016 - 03:23 PM

I plan to build my house to passive house principles,

#44 DavidofMersea

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Posted 09 April 2016 - 03:24 PM

View Postjsharris, on 09 April 2016 - 01:17 PM, said:

No they don't, and there is no such thing as "Passive House Status". A house can be a PHI certified Passiv Haus,

This is what I meant when I said a house had Passive House status, meaning it was up to a certified standard

#45 Crofter

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Posted 09 April 2016 - 03:41 PM

View PostDavidofMersea, on 09 April 2016 - 03:24 PM, said:

This is what I meant when I said a house had Passive House status, meaning it was up to a certified standard

A house can be technically up to or beyond the performance level of a PH, just without spending the money and going through the hassle of actually getting tested and certified. I think most users of this forum would agree that it is not really worth spending that money. That is quite distinct, however, from taking a decision to build a poorly perfoming house.

#46 jsharris

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Posted 09 April 2016 - 03:46 PM

View PostDavidofMersea, on 09 April 2016 - 03:24 PM, said:

This is what I meant when I said a house had Passive House status, meaning it was up to a certified standard

Sorry, that's not how I read this quote:

View PostDavidofMersea, on 09 April 2016 - 12:41 PM, said:

There is a body that measures the air tight performance of your house, and gives you a certificate if they find it is above a certain standard, that is what I was referring to when I said Passive House Status

What you wrote above is that "there is a body that measures the air tight performance of your house". There is no such body, there are a number of companies that do air leakage testing for new houses, you can use any one of them, whether you are building an ordinary house, a certified Passiv Haus, a non-certified passive house or whatever.

You also wrote "and gives you a certificate if they find it is above a certain standard", when they don't. They give you a test report, and they frankly don't care what the result is. If the air leakage doesn't meet either the standard you aspire to, the standard that the PHI demand, or the standard that your building control body require, then the air test company really couldn't care less; it's up to the builder to get the house to meet whatever specification has been set, be that the builder, the building control body, the personal desire of the owner or a body like the PHI.

I set out briefly what a Passiv Haus is, and how it is certified, in my previous post, explaining that Passiv Haus certification is very much more complex than just obtaining a good air leakage test report (note, it is not a certificate, just a report).

FWIW, I don't believe that building a house with Passiv Haus certification makes sense economically. Building a house that doesn't need much, or any, energy to keep it comfortable makes a great deal of sense, and the best way to do that is to follow the basic principles set out by the PHI a couple of decades ago.

Edited by jsharris, 09 April 2016 - 03:46 PM.


#47 DavidofMersea

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Posted 09 April 2016 - 04:49 PM

View Postjsharris, on 09 April 2016 - 03:46 PM, said:

Sorry, that's not how I read this quote:

> It was my fault as I used a capital "S" when I wrote status

What you wrote above is that "there is a body that measures the air tight performance of your house". There is no such body, there are a number of companies that do air leakage testing for new houses, you can use any one of them, whether you are building an ordinary house, a certified Passiv Haus, a non-certified passive house or whatever.

> I thought it was governed by one body, but you are probably right

You also wrote "and gives you a certificate if they find it is above a certain standard", when they don't.

> I was watching a film about an air tightness test, and when the house got below a certain level, they issued a certificate. I appreciate that whilst air tightness is a good start, there is more to a good house than air tightness, like no cold bridging for example

FWIW, I don't believe that building a house with Passiv Haus certification makes sense economically. Building a house that doesn't need much, or any, energy to keep it comfortable makes a great deal of sense, and the best way to do that is to follow the basic principles set out by the PHI a couple of decades ago.

. I am with you on that one JH


#48 jsharris

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Posted 09 April 2016 - 05:01 PM

Like many others here, our build has had it's air test (as many self-builds may have to, whether built to low energy standards or not) and you don't get any certificate from anyone. All you get is a test report that shows the measured air leakage for positive and negative pressurisation, together with details of the test method and equipment used and any major air leaks that may have been found. Our air test report showed that on the first test (before adjusting the door hinges and fixing the leaks through the keyholes) we had an air leakage of 0.45 air changes per hour (so well under the 0.6 ACH requirements for a Passiv Haus) and it also gave the result in the format needed for building control, which was 1.22m³/m² of floor area/hour at 50 Pa pressure differential (the max allowed under current UK building regs is 10m³/m²/hr).

Cold bridging isn't a massive energy loss problem, it's really a problem with regard to interstitial condensation within the structure, which may well affect its long term durability. There is certainly additional heat loss from cold bridges, but its the impact on durability that would really worry me.

Edited by jsharris, 09 April 2016 - 05:03 PM.


#49 gravelld

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Posted 09 April 2016 - 07:25 PM

Quote

. I am with you on that one JH
To be clear, I'm pretty sure Jeremy was saying it's the certification that doesn't make sense economically, not the performance.

#50 joiner

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Posted 10 April 2016 - 06:45 AM

He was.

#51 PeterStarck

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Posted 10 April 2016 - 07:48 AM

View Postjsharris, on 09 April 2016 - 03:46 PM, said:

FWIW, I don't believe that building a house with Passiv Haus certification makes sense economically. Building a house that doesn't need much, or any, energy to keep it comfortable makes a great deal of sense, and the best way to do that is to follow the basic principles set out by the PHI a couple of decades ago.

I was confident to design my own house and use the PHPP to ensure it met PH criteria. To be fair if you are not able to do that you would need to trust and pay someone to do that for you. The only guarantee you would have is their word or to have the house PH certified.

#52 jsharris

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Posted 10 April 2016 - 08:21 AM

View PostPeterStarck, on 10 April 2016 - 07:48 AM, said:

I was confident to design my own house and use the PHPP to ensure it met PH criteria. To be fair if you are not able to do that you would need to trust and pay someone to do that for you. The only guarantee you would have is their word or to have the house PH certified.

You're right, Peter, but my hope is that we can make the design and construction of low energy houses easier to understand and less daunting for those that don't have the budget to have a certified PH built. I suspect that there are a few members of this forum who have built, or are building, self-builds that will have better energy performance than a standard, just-meets-building-regs, house, as a consequence of reading the experiences of those of us that have built low energy houses.

My main criticism of the PHI, other than the relatively high cost of certification, is that they have, probably unwittingly, created an air of mysticism around low energy house design and construction that has led to the wide spread view that it is very expensive, needs wacky looking designs and is something only a small minority of self-builders could aspire to.

If those of us who have proved that you can build a normal looking house, that is comfortable and needs little or no heating, can help to spread the word that any self-builder could have this sort of performance. then that has to be a good thing. If those in the various building trades read this forum and learn that there's nothing really mystical or complex about building better houses, then that will also help. Many more people read this forum than contribute, so in some respects it does act as a learning resource, which is, in my view, a good thing, as long as what's written here is accurate and not misleading.

Edited by jsharris, 10 April 2016 - 08:22 AM.
typo


#53 joiner

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Posted 10 April 2016 - 09:21 AM

I have tried to make these arguments to two "successful developers", both of whom snort in disbelief then refuse to even consider the offer of information, so what hope! :rolleyes:

#54 jsharris

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Posted 10 April 2016 - 09:38 AM

View Postjoiner, on 10 April 2016 - 09:21 AM, said:

I have tried to make these arguments to two "successful developers", both of whom snort in disbelief then refuse to even consider the offer of information, so what hope! :rolleyes:

That was the reaction I had from several building companies I approached to build our house, and even from one small builder who I approached with a view to getting him to look after all first and second fix and finishing work on the erected frame.

There's this widespread view in building that there's nothing wrong with the way they've been building houses for years. Getting builders to accept that there are better ways to build houses, and that those better ways won't be less profitable, is an uphill struggle. A lot of it is "fear of the unknown" I think. We've had people work on the house who have been a bit put off by my stipulation that the airtight inner skin was sacrosanct, and when doing anything they just had to bear in mind that putting holes in it wasn't acceptable. All ended up saying that it was no more difficult than working on any other house, just different.

#55 ProDave

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Posted 10 April 2016 - 09:59 AM

Re the "better house needn't cost more" debate. Let me give you an example.

The "normal" way of building a timber frame house, is to then leave a cavity and clad the outside either with facing bricks, or blocks and render. All that is, is an expensive rain sheild. It adds virtually nothing to the insulation levels of the house.

So on my build I chose not to do that. Instead I am cladding the outside in 100mm thick wood fibre board screwed directly to the frame, and the render goes onto the wood fibre board. The cost is broadly similar to a blockwork skin, but the difference is that it adds an extra layer of insulation and helps with the air tightness of the building. It also simplifies the foundations a little.

So for much the same price, I get a better insulated more air tight building. Why would you want to do it the old way?

Edited by joiner, 10 April 2016 - 10:11 AM.
"blockwork" for "blokeork"


#56 PeterStarck

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Posted 10 April 2016 - 03:12 PM

My next door neighbour is having a new bungalow built by a local building company. It seems the builder had quite a lot of input as to what it will look like. It's conventional brick and block construction and the bricks they used are designed to look old. They have since gone round chipping bits off the bricks to make it look 'weathered'. He's not interested in using more insulation than is necessary to meet regs. only interested in what it looks like. According to him It should look old and as though it has been there for years. He can't understand my build!

#57 joe90

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Posted 10 April 2016 - 03:16 PM

I am also using "old" looking bricks as I want to have a cottage that looks in keeping with the area. However I will have a 300mm cavity full of insulation and no formal heating system, best of both worlds.

#58 PeterStarck

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Posted 10 April 2016 - 03:21 PM

The trouble is there are eight houses in the hamlet and they all look different, so it's difficult to know what looks in keeping with the area. At the moment the insulation that has been fitted inside is blowing out through the window openings!

#59 DavidofMersea

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Posted 10 April 2016 - 03:25 PM

View Postgravelld, on 09 April 2016 - 07:25 PM, said:

To be clear, I'm pretty sure Jeremy was saying it's the certification that doesn't make sense economically, not the performance.

So was I. That is what I was agreeing with him

#60 declan52

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Posted 10 April 2016 - 03:43 PM

View PostPeterStarck, on 10 April 2016 - 03:21 PM, said:

The trouble is there are eight houses in the hamlet and they all look different, so it's difficult to know what looks in keeping with the area. At the moment the insulation that has been fitted inside is blowing out through the window openings!
Bit of quality work there.