Allow me to clarify Fairygirl.
I have no axe to grind with or for any of these methods or people discussed below and the opinions offered as always are my own, but these are my opinions in this regard.
Regardless of what system you choose there are some basic do's and don't.
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UFH does not seem to sufficiently responsive to provide comfortable level of heat - by itself - in our variable climate.
This is because in general it is installed under timber floors - timber being an insulant - and not under tiled floors [for child safety re falls perhaps] and there is a thermal inertia in the system which usually means it "runs hot"
People who claim to know - both house owners and professionals to whom I have spoken - suggest UFH needs to be set at the lower level of comfort and radiators or other local space heaters used for warm up as required with sudden cold snaps.
I have also heard it said that the pump for such systems needs to run constantly and that it should be undersized to allow it to run efficiently at capacity.
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Assembling a kit of parts will not guarantee an A2-rated house.
SIPS is presented as a technically brilliant sandwich of elements but think about this - every hole, every joint compromises the ideal, unless the perfection is continued.
If you're going to move from traditional build to a specialist building systems you'll need someone very experienced at installing this system to carry out the work and offer certification.
You should also satisfy yourself that the system will not develop problems in whatever term the longest and/or most exposed house built using this system has been erected for by visiting the premises and talking to people who use the system.
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Certain groupings of technologies will achieve this or greater, but these are technologies that are known to work together - eg the Passivehaus system.
The Passivhaus system raises different concerns, such as building off insulation and the effects on health of super-sealing and reliance on changing filters to achieve good air quality - these may also be of concern to you, depending on your specification.
However, if I was seriously thinking of this kind of performance I would be looking at passive house construction, not a factory production method, unless it produced the whole building as a fait accompli and I had costings to inform my choice.
This is because site assembly inevitably compromises factory production - this is why traditional methods have so many failsafes included in terms of the built work regarding timing and drying out of materials etc. - they allow for known flaws bring introduced and work around them.
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In particular, I am not convinced by the long term performance of some of the joints and element overlap conditions when it comes to interstitial condensation in SIPS - based projects.
I don't have a particular axe to grind with the system, that's just my tuppence worth.
When you look at the sections and you see large highly insulated plates of material being butt jointed and lap jointed you naturally wonder will there be failure or leakage at the joints.
When you look at sheets of perfection, the points of change - opes, angles, joints - these seem to be the weak points - in principle.
Structural expansion and contraction will tend to open up large joints like that.
Or will they just use a giant internal film to seal the house construction - and what happens when someone puts a nail through one of the walls?
There are other systems out there which have service voids and even entire secondary layers inboard of the sealing membrane to avoid such problems with penetrations and services.
Regardless of this, you need someone competent to achieve it in terms of the both the design and the execution.
Even with a competent architect reviewing and researching the materials and technologies being used and satisfying himself that the detailing will hold up at corners, thresholds and opes, you cannot use just anyone as the contractor.
At the least, he will need to be experienced and if possible factory or manufacturer certified.
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There is some feedback on the profession that people who "claim" to have achieved more that A3 may not actually attain this level of performance over time, due to thermal looping, poor placement of elements, sealing elements, materials being compromised by moisture build up, etc.
On the face of it SIPS may address these problems, but every system has its own crosses to bear - SIPS' problem is that as far as I know it is not widely used in the building industry and therefore there may be a lack of feedback over time available.
We need independent testing over time on which to base competent professional assessment whereas what we seem to see are reports of brilliance being promulgated in trade or special interest magazines - about the same people who take out advertisements in those publications!
That's not competent independent, empirical, professional review - that's marketing!
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For all that I am wary of the "sell" on sustainable building and retrofitting,
Construct Ireland and Jeff Colley are publishing what seem to be empirical tests and external insulation seems to be holding up quite well to the investigations so far.
This of course is a bolster to the retrofitting industry but the results are there and the retrofitting technologies are easier to replace or repair if faults develop, since by definition most of the are not integral to the structure, apart from the cavity bead installation.
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As a cautionery note, no-one has tested the performacne of a highly insulated house using petroleum based insulation products or rockwool, timber frame or traditional, in a fire situation, that I am aware of.
I think the building control officers, fire officers and others are holding back from commenting for whatever reason and I think we ignore the issue of fire propagation ansafety at our peril.
For example, three private houses I designed and saw erected have concrete slab or steel and concrete slab upper floors and 225mm concrete block inner leaves and partitions.
While these have been built over the past twenty years or so, the last one acheived an A3 rating.
Thermal mass and sound insulation as standard.
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I have written about these technologies over the past two years in response to public interest.
If you search through the posts on AAM you may find one or two people with experience of this system and you should contact them.
Everyone like new technologies, but building professionals tend to prefer tried and tested, which for us means a twenty [yes, 20!] year review period in the climate and location of choice.
FWIW
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.