Green Building Forum - Insulating 300m2 wall area? Tue, 19 Dec 2023 04:19:27 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303589#Comment_303589 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303589#Comment_303589 Thu, 28 Sep 2023 19:27:32 +0100 Victorianeco
The build is a 60s cavity construction right on the sea front.

I assume EWI would be best but at ~£110m2 it just seems it outweighs any energy savings in the long run...

£30k plus scaffold, roof extensions and so on.... we'd also like to renew the windows at a great expense.

What are people's thoughts? It's a bit of a 'slightly' different project compared to my previous mid terraced renovation....]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303593#Comment_303593 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303593#Comment_303593 Thu, 28 Sep 2023 22:35:25 +0100 Mike1
Ideally you'd get an EPC evaluation of your plans as a whole, so you can see if you can do anything more to push into the next band up (especially if that band is C). However since the EPC system seems likely to be heavily revised in the next few years, that's tricky at the moment.

Here in France the EPC rating (calculated differently to the UK) already has a significant impact on the property value.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303595#Comment_303595 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303595#Comment_303595 Thu, 28 Sep 2023 23:45:57 +0100 Victorianeco
People are more interested in property size, location, garden size, proximity to amenities and so forth.

I don't think spending ~£40k would increase the value of the property by £40k and certainly wouldn't save £40k in energy over my lifespan....

Just my thoughts...]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303597#Comment_303597 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303597#Comment_303597 Fri, 29 Sep 2023 07:04:39 +0100 Dominic Cooney Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303598#Comment_303598 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303598#Comment_303598 Fri, 29 Sep 2023 08:06:22 +0100 GreenPaddy
An example of before and after, where EWI was added (with cavity filled walls), then over clad in timber. Floors insulated, loft insul improved. New windows also, etc. There will be a lot more interest when the time comes to sell, due to the visual improvement, which will drive up the selling price...plus it will need a fraction of the heating energy.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303599#Comment_303599 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303599#Comment_303599 Fri, 29 Sep 2023 08:07:07 +0100 GreenPaddy Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303601#Comment_303601 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303601#Comment_303601 Fri, 29 Sep 2023 10:38:14 +0100 fostertom
Then, next step is typically new (plastic) windows, which can pay back in property value, but has small benefit in overall thermal improvement per £. Piecemeal things like internal wall insulation even less - a lot of money, fiddly work, disruption, loss of floor space, can't safely be really strong insulation and is riddled with thermal bypasses.

For thermal improvement per £, full EWI incl new windows can't be beat - tho it's a lot of money, it's even more thermal performance pro rata, by a long chalk. Plus far less internal disruption. It's also sufficiently 'thermal' to make expensive upgrade of heating system unnecessary - save that money and spend it on insulation/airtighness instead. That is, no need for UFH, ASHP, instead the clunky old inefficient existing heating will be called upon so infrequently, that it can stagger on for some years perhaps, with two thirds of the old rads removed. Still need water heating of course.

Yes, there's a payback-justification gap, between the 'low hanging fruit' and full EWI+windows. I discourage clients from spending money in that gap.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303604#Comment_303604 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303604#Comment_303604 Fri, 29 Sep 2023 12:13:53 +0100 Mike1 Posted By: VictorianecoThe EPC value I find has little to no impact on value in the UK of a property...It may not be large (yet), but it does play a role. For example:

"We provide causal evidence of households willingness to pay for a higher energy rated property, documenting a 1-3% premium to a higher energy efficiency rating at the national level, and a 3-6% premium in the London market."
- https://eprints.soton.ac.Uk/474768/1/EPC.pdf (published last year)

Here in France, where the EPC rating scheme is more logical than the UK's, and where bans & restrictions on renting most properties below E rating came in just over a year ago, the effect is larger. Lower rated properties are now coming onto the market in much larger numbers and sell at a discount to investors, who can take advantage of Government loans and tax breaks to upgrade them. Highly rated properties sell for a premium. I imagine the UK will eventually catch up.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303608#Comment_303608 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303608#Comment_303608 Fri, 29 Sep 2023 15:00:26 +0100 Peter_in_Hungary Posted By: VictorianecoA property myself and my wife are looking at has approximately 300m2 external wall area.

The build is a 60s cavity construction right on the sea front.

I assume EWI would be best but at ~£110m2 it just seems it outweighs any energy savings in the long run...

£30k plus scaffold, roof extensions and so on.... we'd also like to renew the windows at a great expense.

What are people's thoughts? It's a bit of a 'slightly' different project compared to my previous mid terraced renovation....
What is the plan for the house? Short term and sell on, medium term or the last one before they cart you off?

Short term - make it look pretty and add a bit of insulation in the loft

Medium term -
Posted By: fostertomIn terms of thermal improvement per £, 'low hanging fruit' like loft insulation, cav wall insulation, draught stripping pay very well.

and plastic windows (maintenance free(ish) especially on the sea front)

Long term - As medium term but perhaps more loft insulation and better quality plastic windows, perhaps EWI on the coldest side (unless the walls have facing bricks) but EWI all over is IMO difficult to justify the ROI at 40K especially as you will be doing CWI anyway - which will be needed before EWI.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303609#Comment_303609 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303609#Comment_303609 Fri, 29 Sep 2023 16:22:59 +0100 fostertom Posted By: Peter_in_Hungarywhich will be needed before EWIWhy? To prevent air blowing about in the cavity?

The inner leaf will be part of the interior environment, at interior temperature and contributing its mass to stabilise that temperature. As long as the cavity is nowhere open to the outside, loft, underfloor void etc, it also will be at same interior temp. So if air also at that temp is free to move around in it, that's no problem, any more than room air moving around.

No need to cavity fill before EWI, as long as it's well sealed. If it's not sealed then much of your EWI money's being wasted, even if you have CWI.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303612#Comment_303612 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303612#Comment_303612 Fri, 29 Sep 2023 18:33:21 +0100 Peter_in_Hungary Posted By: fostertomWhy? To prevent air blowing about in the cavity?
Yes
Posted By: fostertomNo need to cavity fill before EWI, as long as it's well sealed. If it's not sealed then much of your EWI money's being wasted, even if you have CWI.

But it is my understanding that CWI Mineral wool blown in at a density of at least 18 kg/m3 is normally enough to prevent air movement in a fully filled cavity and probably the easiest way to stop cavity draughts. Mind you getting someone to install CWI properly could be a challenge in itself.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303613#Comment_303613 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303613#Comment_303613 Fri, 29 Sep 2023 19:49:07 +0100 Victorianeco
Yes, cavity wall sealing would be a must I'd imagine? Probably not as easy as it sounds surely particularly being in the sea front.

It needs new windows anyway, so we are off the opinion plastic would be better than timber or alu-clad?

Any recommended supplier for plastic windows?

The render is in good order, so we'd probably look to keep that for the time being.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303615#Comment_303615 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303615#Comment_303615 Fri, 29 Sep 2023 22:50:44 +0100 RobL Cables in cavities
No cavity closers at the top
3cm dia holes in inner and outer leaf in places (out of sight between floors or behind cladding)
We had it CWI with glass fluff then EWI.

Foam fill if done well (the mix must be perfect) likely gives lower air leakage than fluff.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303617#Comment_303617 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303617#Comment_303617 Sat, 30 Sep 2023 09:10:16 +0100 Victorianeco
It may well be that it has already had CWI...]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303620#Comment_303620 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303620#Comment_303620 Sat, 30 Sep 2023 15:01:45 +0100 Mike1 Posted By: VictorianecoIt needs new windows anyway, so we are off the opinion plastic would be better than timber or alu-clad? Any recommended supplier for plastic windows?
Personally I'd choose alu-clad. And always avoid plastic which aren't very green and have multiple drawbacks:

- environmental & health impact - toxins and pollution are inherent to PVC - see https://www.greenspec.co.uk/building-design/polyvinyl-chloride-pvc-environment-health/
- surface degradation and discolouration through UV light & surface deposits
- susceptibility to impact damage (depending on location) & cracks through thermal cycling
- questions over the long-term availability of suitable spares - replacement glazing beads, hinges, etc.
- overall unremarkable life expectancy - typically 20 to 30 years, but depending on quality
- uValues not always great, depending on construction
- clunky visual appearance
- limited recycling facilities]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303625#Comment_303625 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303625#Comment_303625 Sun, 01 Oct 2023 07:55:31 +0100 Victorianeco Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303626#Comment_303626 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303626#Comment_303626 Sun, 01 Oct 2023 08:11:21 +0100 fostertom Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303629#Comment_303629 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303629#Comment_303629 Sun, 01 Oct 2023 12:54:32 +0100 Victorianeco
"UPVC windows are inherently corrosion-resistant, making them an excellent choice for coastal homes. Unlike metal frames that can rust over time, UPVC remains unaffected by salt and moisture exposure."

"High-performance uPVC windows naturally resist moisture, rotting, rusting and are not affected by salt corrosion either."

Just a few of the top searches that came up in google]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303630#Comment_303630 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303630#Comment_303630 Sun, 01 Oct 2023 13:41:32 +0100 Mike1 Posted By: VictorianecoIs that real world experience or taken from a sales blurb?Real world experience and academic research.

In respect of the latter, the RIBA webiste provides a quick overview, with comparisons to other window materials, here (it is sponsored by Valfac, but they do provide the academic references):
https://www.ribacpd.com/articles/velfac-windows/7834/cradle-to-grave-the-comparison-of-window-life-cycles/200009/]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303633#Comment_303633 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303633#Comment_303633 Mon, 02 Oct 2023 07:15:29 +0100 borpin Posted By: Mike1Personally I'd choose alu-clad. And always avoid plastic which aren't very green and have multiple drawbacks:
Posted By: Victorianeco"UPVC windows are inherently corrosion-resistant, making them an excellent choice for coastal homes. Unlike metal frames that can rust over time, UPVC remains unaffected by salt and moisture exposure."
A friend of mine has plastic windows on a sea front property (as far West as you can get) and the main issue is the aluminium locks have corroded.

Personally, high quality wooden windows, properly treated in the factory win my vote.

Also Triple-glazing is a must. This difference is phenomenal - double glazing should be banned.

If you do go plastic, get lots of spares for them at the time of purchase!]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303634#Comment_303634 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303634#Comment_303634 Mon, 02 Oct 2023 09:42:29 +0100 RobL
Pilkington make a free calculator (Pilkington Spectrum), which shows differences (light, heat, acoustic, etc).

FWIW we have 35 yr old uPVC, all still fine with zero maintenance except retrofitting planitherm U=1.1 glass and foam filling sections. My parents had a massive 1890 ish house - after that (and my own Victorian starter home) I'm not so enamoured by rattling rotten wooden windows which seem to constantly needing painting. If uPVC didn't have bad environmental credentials it would be the perfect window frame material IMHO.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303639#Comment_303639 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303639#Comment_303639 Mon, 02 Oct 2023 11:08:21 +0100 fostertom Posted By: RobLI'm not so enamoured by rattling rotten wooden windows which seem to constantly needing paintingA masterstroke of 'political' subliminal innuendo! The reader may not notice that you've implanted 'rattling, rotten, needing painting' as the character of wooden windows.

No one's suggesting prehistoric wooden windows (i.e. anything pre-21C and many since) are OK - this is about the 'best' breed of Scandinavian-style factory-glazed and -finished timber windows, with or without Ali-clad exterior, that even housebuilders are now providing.

These maintainable/adaptable windows will still be in service long after the plastic ones have died for any of the several reasons mentioned above. Even 'retrofitting planitherm' to plastic windows is surprising - all credit - their beads are tricky to remove/replace undamaged; piece of cake with timber.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303641#Comment_303641 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303641#Comment_303641 Mon, 02 Oct 2023 11:52:27 +0100 Peter_in_Hungary Posted By: Mike1In respect of the latter, the RIBA webiste provides a quick overview, with comparisons to other window materials, here (it is sponsored by Valfac, but they do provide the academic references):
https://www.ribacpd.com/articles/velfac-windows/7834/cradle-to-grave-the-comparison-of-window-life-cycles/200009/
A good comparison, whilst probably outside of the remit for the article, it is a pity that there was no price comparison.
For many replacing windows comes at a time when general upgrading is done, often when just moving in. At such times budget limitations often play a large part of decision making.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303645#Comment_303645 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303645#Comment_303645 Mon, 02 Oct 2023 13:43:38 +0100 fostertom
So yes, timber windows are more expensive than plastic, but not by a lot on performance. Perhaps more relevant, in Russell's case, as a trade not a consumer-friendly company, are quite arduous to spec and procure.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303799#Comment_303799 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303799#Comment_303799 Sat, 07 Oct 2023 21:07:25 +0100 Victorianeco
Is there a near passive House spec I can read up on somewhere?]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303805#Comment_303805 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303805#Comment_303805 Sun, 08 Oct 2023 09:17:38 +0100 an02ew Posted By: fostertomsave that money and spend it on insulation/airtighness instead

Total agree.]]> Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303807#Comment_303807 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303807#Comment_303807 Sun, 08 Oct 2023 10:02:36 +0100 RobL Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303811#Comment_303811 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303811#Comment_303811 Sun, 08 Oct 2023 12:34:59 +0100 Victorianeco Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303825#Comment_303825 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303825#Comment_303825 Mon, 09 Oct 2023 12:35:14 +0100 borpin Insulating 300m2 wall area? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303853#Comment_303853 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17975&Focus=303853#Comment_303853 Fri, 13 Oct 2023 13:06:09 +0100 cjard
My double glazed windows frequently condense on the outside]]>