# Sips, timber frame or masonry



## about2build (1 Oct 2011)

Looking to get an airtight build and have gotten a quote of 75000 for two storey 2550 sq ft house with sips.....seem very expensive. I know it provides a lot as well as erection for that price but surely could achieve similar u value and finish with masonry buils for 20-30 grand less??! Any thoughts?


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## onq (1 Oct 2011)

I'm not convinced about "airtight" builds at all.

I am aware of what the Green Minister brought it, but I don't think he was well-briefed.

Ireland has a much milder, damper climate than Europe and increasingly cold winter temperatures.

I think that the obsession with sealing is going to impede the "breathability" of the construction and this will lead to problems with interstitial condensation.

Quite apart from the fact thar, whatever about a form of construction, you cannot "seal" a house with kids and that undermines the preposition of sealing in the first place - the prevention of infiltration losses.


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon      as a defence or support - in and of itself - should legal action be      taken.
Competent legal and building professionals should be asked to advise in      Real Life with rights to inspect and issue reports on the matters at      hand.


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## NHG (3 Oct 2011)

+1

Houses need fresh air... otherwise you have mould especially if drying clothes indoors.  

Bedroom windows need to be opened every day hail, rain or snow.


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## onq (3 Oct 2011)

There is of course nothing stopping people opening the windows in their airtight build, but I'm a little concerned about it, that's all.

When you tot up the extra over cost for the initial build and do a calculation putting that amount on deposit for the period over which the capital investment should be depreciated, do you save any money? A recent thread on solar tubes suggested not.

More importantly, when you tot up the extra fabrication costs of these high tech components, is there a huge overall reduction in carbon footprint. Possibly, but possibly you would get nearly as much without the additional services if passive systems were used.

Finally there is the unquantifiable issue of wellness, which depends in large part on air quality. We are told that "vents in the walls" will somehow know when the air quality has deteriorated to such a degree more sir changes are required. Does this not go against the principle of a sealed house? How does this air get in without freezing the place?

There seem to be a lot on unnowns in use that raise serious questions. We need a feedback loop on all of this post-haste before we all end up having a badly exercised immune and personal heating system. Whatever doesn't kill you may not make you stronger, but it usually toughens you up. Look before you leap in this case.


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon       as a defence or support - in and of itself - should legal action  be      taken.
Competent legal and building professionals should be asked to advise in       Real Life with rights to inspect and issue reports on the matters  at      hand.


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## lowCO2design (4 Oct 2011)

onq said:


> I'm not convinced about "airtight" builds at all.
> 
> I am aware of what the Green Minister brought it, but I don't think he was well-briefed.
> 
> ...


I think you confuse air-tightness with adequate ventilation here and also the structure/ material breathability which is different again AND inflitration losses are very different to opening doors!

we live in particularly leaky homes in this country which leave out a lot of heat. the answer is to achieve high levels of insulation and air-tightness

we also live in homes that in many cases do not have enough appropriate ventilation. the answer is to either use passive stack with DCMV or MVHR either of which can control RH (during the heating system) while check Co2 levels and reduce your heating spend over the 'hole in the wall' /win method

there are membranes on the market that allow you to have 'breathablity' but achieve air-tightness. the breathability of many typical block structures is minimal as well as many popular insulation products such as the PIR's or EPS's. thats is not to say that breathability is not important in for instance in old buildings or in many roof build ups. 

I agree that DOE's part L is not a great Document but what has the green  minister to do with it? his mandate was to reduce energy consumption  in buildings as per the EU directives..


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## lowCO2design (4 Oct 2011)

onq said:


> When you tot up the extra over cost for the initial build and do a calculation putting that amount on deposit for the period over which the capital investment should be depreciated, do you save any money? A recent thread on solar tubes suggested not.


 could you post this data please, thanks


onq said:


> More importantly, when you tot up the extra fabrication costs of these high tech components, is there a huge overall reduction in carbon footprint. Possibly, but possibly you would get nearly as much without the additional services if passive systems were used.


 often times the carbon footprint/ Embodied energy increases for the actual build, but the energy savings and hence carbon footprint during the buildings lifespan is much less and more than compensates..


onq said:


> Finally there is the unquantifiable issue of wellness, which depends in large part on air quality. We are told that "vents in the walls" will somehow know when the air quality has deteriorated to such a degree more sir changes are required. Does this not go against the principle of a sealed house?


 yes 'wellness' is most important here as is occupant comfort but you confuse required ventilation with uncontrolled air-infiltration otherwisde known as drafts!





onq said:


> How does this air get in without freezing the place?


 i dont understand your question


onq said:


> There seem to be a lot on unnowns in use that raise serious questions. We need a feedback loop on all of this post-haste before we all end up having a badly exercised immune and personal heating system. Whatever doesn't kill you may not make you stronger, but it usually toughens you up. Look before you leap in this case.


 The issue you raise regarding the feed back loop is interesting. there was a post occupancy stage (in I believe) the pre 80's RIBA which was removed probably due cleints not wanting to pay for it. But it is definitely something that should be revisited. there is also the issue that architects and clients not wanting their 'sick buildings' known as a sick buildings and so maybe the lessons aren't being learned quick enough...


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## lowCO2design (4 Oct 2011)

about2build said:


> Looking to get an airtight build and have gotten a quote of 75000 for two storey 2550 sq ft house with sips.....seem very expensive. I know it provides a lot as well as erection for that price but surely could achieve similar u value and finish with masonry buils for 20-30 grand less??! Any thoughts?


you possible could save money with a block build. but would lose the benfiets of the SIPs: quick erection and watertight house, off site construction mm perfect etc
what exactly is included in this SIPs package?


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## onq (4 Oct 2011)

about2build said:


> Looking to get an airtight build and have gotten a quote of 75000 for two storey 2550 sq ft house with sips.....seem very expensive. I know it provides a lot as well as erection for that price but surely could achieve similar u value and finish with masonry buils for 20-30 grand less??! Any thoughts?



I presume you're missing a "0" in the quotation. 

€75,000 for 2,250 sq.ft? - not a chance, not even in this economic climate.

Even a rock bottom €50 a sq.ft. "I'm out of here after the second payment" quotation would yield 50 x 2250 - €112,500.

Assuming you meant €750,000 that's €333.33 per sq.ft. which is three times the cost for a basic house and it shows you where the rip off merchants have relocated to.


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon        as a defence or support - in and of itself - should legal action   be      taken.
Competent legal and building professionals should be asked to advise in        Real Life with rights to inspect and issue reports on the matters   at      hand.


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## onq (4 Oct 2011)

lowCO2design said:


> could you post this data please, thanks


Its in a recent thread on AAM, but "recent" for me is 100 posts ago and more so its not to hand.


> often times the carbon footprint/ Embodied energy increases for the actual build, but the energy savings and hence carbon footprint during the buildings lifespan is much less and more than compensates..


Translates to "pay me the money now and I promise you this will all work out in your favour over the next twenty years" - snake oil.


> yes 'wellness' is most important here as is occupant comfort but you confuse required ventilation with uncontrolled air-infiltration otherwisde known as drafts!


I'm not confusing anything - I'm implying by my question that "on-demand" wall vents don't seem to work!


> i dont understand your question


If you follow the exchange a bit, it might become clear, but you seem to have missed my point above 


> The issue you raise regarding the feed back loop is interesting. there was a post occupancy stage (in I believe) the pre 80's RIBA which was removed probably due cleints not wanting to pay for it. But it is definitely something that should be revisited. there is also the issue that architects and clients not wanting their 'sick buildings' known as a sick buildings and so maybe the lessons aren't being learned quick enough...


Well I'm glad we agree on something, because there are a lot of reports from companies claiming to have done the research that unless systems and insulation are closely tailored to the needs of the occupants and the house and well fitted, they will fail to achieve what they promise.

ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon         as a defence or support - in and of itself - should legal action    be      taken.
Competent legal and building professionals should be asked to advise in         Real Life with rights to inspect and issue reports on the matters    at      hand.


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## lowCO2design (4 Oct 2011)

onq said:


> Translates to "pay me the money now and I promise you this will all work out in your favour over the next twenty years" - snake oil.


 I don't believe it translates as that at all! unfortunately the "passive systems" / "on-demand" as you call them are not working particularly the 'hole in wall ventilation'. and any of the "snake oil" is down to you and I to decipher picking through the claims made by suppliers. this began with you refuting the need for Air-tightness which is as necessary as insulation imo but that should not be confused with proper ventilation or breathability of structure


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## onq (5 Oct 2011)

I'm not disagreeing with your basic premise, but I'm making the point that the payback times don't seem to stack up and the ambient energy systems can often be inappropriate.
I heard a story last evening that some 3rd level college installed state of the art solar arrays on its roof to provide all the hot water needs for the students.  Worked fine over the summer months when there were no students...

ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon          as a defence or support - in and of itself - should legal  action    be      taken.
Competent legal and building professionals should be asked to advise in          Real Life with rights to inspect and issue reports on the  matters    at      hand.


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## Patrick2008 (5 Oct 2011)

One of the major problems I am seeing at the moment is people are making their houses very airtight achieving less than 2 air changes per hour. In other words the house is nearly sealed. However, they are not allowing for a adequate ventilation system so in some cases the attic insulation is dripping wet and sagging. This happened when we had the snow last year and then we had amild spell after. The Irish weather is so unpredictable.

Many self builders and housebuilders are constructing houes as follows: traditional block construction with insulation in cavity, sand cement internal face of external walls to achieve airtightness, mushroom fix 37.5mm insulated plasterboard to internal face of external walls, seal around all penetrations and opening in walls, floors and ceiling with Intello plus seal tape etc, 72mm insulated plasterboard in upstairs ceilings or to walls upstairs if it is  dormar, 300mm attic insulation. Ventilation consists of HVAC units (€5k suply and fit), or just trickle vents in windows and wall vents as in traditonal construction. 

ONQ. I would love to hear your views on how a house should be built without using all this fancy new methods and by using the traditional cavity wall construction with 2 no. 100mm blocks on edge and a 110mm cavity with insulation. Or is this method dead as outlined by Joseph Little Architects.


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## lowCO2design (5 Oct 2011)

I take your point, but I don't think proven technology solutions should be confused poor design strategies.


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## about2build (5 Oct 2011)

Sorry guys I didn't specify what they actually provide for the 70 k SIP Energy arrive to a prepared base, and *supply* and* fit*


all SIP rising walls - both external and  internal
joisting, decking
upper floor walls (where applicable)
gables
SIP roof system
 This leaves a complete SIP envelope, suitably wrapped in  protective membrane(s),  and ready for the application of external  finishes or cladding's, windows &  doors, and roof finishes. It also takes out the need/cost for hollow core mid floor any internal mortar work though plaster boards and skim coat have to be applied. It is factory designed and precise and airtightness is guaranteed with a 5 day construction particularaly impressive. Ventilation is to be achieved using mvhr technology and thus control air loss rather than the hole in the wall infiltration method. Ive had a timber frame quote back as well since original quote and though it came in cheaper originally once all the add ins that are offered are calculatd in its more or less the same. What do ye think for the amount of work done in that time for that price?....keeping in mind that I am going down this route re air tightness, high spec insulation and integrated ventilation system anyway I just think though achievable with bricks and mortar the cost may become equivocal in the end


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## onq (5 Oct 2011)

Patrick2008 said:


> One of the major problems I am seeing at the moment is people are making their houses very airtight achieving less than 2 air changes per hour. In other words the house is nearly sealed. However, they are not allowing for a adequate ventilation system so in some cases the attic insulation is dripping wet and sagging. This happened when we had the snow last year and then we had amild spell after. The Irish weather is so unpredictable.
> 
> Many self builders and housebuilders are constructing houes as follows: traditional block construction with insulation in cavity, sand cement internal face of external walls to achieve airtightness, mushroom fix 37.5mm insulated plasterboard to internal face of external walls, seal around all penetrations and opening in walls, floors and ceiling with Intello plus seal tape etc, 72mm insulated plasterboard in upstairs ceilings or to walls upstairs if it is  dormar, 300mm attic insulation. Ventilation consists of HVAC units (€5k suply and fit), or just trickle vents in windows and wall vents as in traditonal construction.



This isn't a comment on how compliant it is otherwise.
I'm only going to comment on weaknesses in the spec above.

One weak point in the above specification jumps out at me - the 300mm attic insulation on the flat.
This tends to create a cold micro climate in the attic space leading to condensation esp with downlighters.

37.5mm warm-board isn't anywhere like enough so it will depend on the insulation in the cavity walling itself for compliance.
Omissions in the above specification would include the floor insulation for example 
I have serious concerns with the MVHR systems as posted previously.

And so far nobody has addressed how a super-sealed house is supposed to actually function with kids and pets.
The theoretical sealing and heat retention goes out the window when you factor in normal human activities.

-----------------------

Which brings me to the main part of the carbon footprint - making cups of tea.
Working from home (such work as there is, these days!) need lubrication.

All the measures to insulation the house taken together won't make me a cup of tea 
Flippancy aside, this points to the hole in the government strategy.

How we can get credits for generating electricity.
With these we can all make "free" cups of tea!


ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon           as a defence or support - in and of itself - should legal   action    be      taken.
Competent legal and building professionals should be asked to advise in           Real Life with rights to inspect and issue reports on the   matters    at      hand.


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## lowCO2design (6 Oct 2011)

Patrick2008 said:


> I would love to hear your views on how a house should be built without using all this fancy new methods and by using the traditional cavity wall construction with 2 no. 100mm blocks on edge and a 110mm cavity with insulation. Or is this method dead as outlined by Joseph Little Architects.


dead as it doesnt comply with current Building regs


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## lowCO2design (6 Oct 2011)

about2build said:


> Sorry guys I didn't specify what they actually provide for the 70 k SIP Energy arrive to a prepared base, and *supply* and* fit*
> 
> 
> all SIP rising walls - both external and  internal
> ...


this price seems ok for 250m2... I would however want to the contracts, the details (particular with slab, around opes, penetrations AND who repairs the air-tightness after other sparks/plumber are on-site), the air-tightness clause, the interface agreements between main contractor/ sip/ win etc. I would also be trying to get the same guys to do the cladding a roofing/flashings (if they were reasonably priced) as they would know their structure and possibly take more care...


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## lowCO2design (6 Oct 2011)

ONQ you posts often confuse me?? I been following your forum for sometime now and you seem like knowledgeable architect but then come out with things like


onq said:


> I have serious concerns with the MVHR systems as posted previously.
> *And so far nobody has addressed how a super-sealed house is supposed to actually function with kids and pets.*
> The theoretical sealing and heat retention goes out the window when you factor in normal human activities.


 its like there's a mass of conflicting reasons, where by the end of a statement it seems like you need to go and visit a few well designed MVHR homes, that have kids! Now i do except that mvhr and sealed homes must be built properly and properly designed. but a 'super sealed' house works the same with kids and pets as any other house. you have a good building fabric, and a good ventilation system, opening the door does not change that. its no different to you or I as kids, getting told to shut the door to keep the heat in..

now here's where I get lost again your "tea" analogy? 
are you saying that the governemnts should be pushing for more domestic electrical generation to reduce carbon footprinting? surely this would be more efficient on a larger scale..


onq said:


> this points to the hole in the government strategy.
> How we can get credits for generating electricity.
> With these we can all make "free" cups of tea!


so from the last few posts can I surmise that you would prefer that money be spent on electrical generation rather than modern methods of construction to reduce heating and HW demand in our homes?


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## onq (6 Oct 2011)

lowCO2design said:


> dead as it doesnt comply with current Building regs



Can you post the link to Joe's piece? I haven't read it yet, but I know we specced a house to current standards using cavity walling only last year and it was compliant.

ONQ.

[broken link removed]

All advice on AAM is remote from the situation and cannot be relied upon            as a defence or support - in and of itself - should legal    action    be      taken.
Competent legal and building professionals should be asked to advise in            Real Life with rights to inspect and issue reports on the    matters    at      hand.


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## Patrick2008 (6 Oct 2011)

http://www.josephlittlearchitects.com/documents/cavity_wall_paper.pdf

we are also building houses using cavity walls and are all in accordance with current regs and achieving B2 energy rating. I would love to hear anyones IINDEPENDENT) views on trying to find the balance between too air tight and too draughty.


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## lowCO2design (7 Oct 2011)

I stand corrected re 100 cavity compliance

you would like to google:

"cavitytherm" (no affiliation) the product can supposedly achieve .16 /m2k in a standard 100mm cavity

I would also recommend you take a look at "denby dale passive house diaries the walls" "week seven"


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## lowCO2design (7 Oct 2011)

Patrick2008 said:


> we are also building houses using cavity walls and are all in accordance with current regs and achieving B2 energy rating. I would love to hear anyones IINDEPENDENT) views on trying to find the balance between too air tight and too draughty.



it is going to be difficult from now on as we head towards even tough part L regulations. I'm an arch tech and certified passive house designer so I have my preferences but I'm certainly 'INDEPENDENT'

the current regs are finally addressing air-tightness, some would say  our  Regs are not going far enough, considering how far we've come with   insulation.. I've just had a read of the new US codes (following a read   of the greenbuilding advisor article) and they seem to be a small bit   ahead of us in Ireland. But it's becoming clear that with increased   air-tightness there are questions and decisions to be made regarding how   we supply adequate fresh air to our new and retro-fitted homes.
So  here's the thing, the PHPP insists on MVHR, and I for one do see the   merit in its use. But then there's occupant behaviour, maintenance,   initial product cost and electrical running costs to consider. There are   also the irrational fears associated with units not working and the  odd  horror story that's pre-empted new codes of practice and safety   features -  But such fears can be applied to anything new, just like   electricity less than 50 years ago. Now that's all mentioned, is there   any alternative?

Is Demand controlled Mechanical ventilation an  alternative to MVHR,  when the overall running costs + initial set-up  costs are considered?  With DCMV's reduced electrical and primary energy  consumption, is there  some merit to this? It also has the bonus of  having some of its kit  already familiar to users as its includes direct  extract fans at the  usual kitchen & wc locations.
Irish  Building regs & DEAP are crap and do not consider heat gains  as  being a major factor. they do not require a low enough air-tightness   factor either.I do worry that some are calling  this a natural or passive alternative to  MVHR systems which they are not.  although.. there are some completely passive system on the market but all have there issues, one is a window vent system that is of the market at the moment.. you may like to check-out the BedZed project its ventilation solution..


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