External Wall Insulation- Suitable ?

[TeeDee]

Just interested in peoples thoughts on this , I work for a renewables related company but am genuinely interested in what the future may bring for all UK housing stock in a time that seems to signal that Energy efficiency and thermal insulation of a house is nothing to be taken lightly any longer.

I see in the way of projects a lot of big money McMansions that benefit from a very healthy budget and because they tend to be new builds means retrospectively trying to improve insulation or energy efficiency isn't a big concern.

My interest relates to current bread & butter UK housing stock of which it must be said is a myriad of types and periods. This is what tends to need the greater focus if we are going to make significant changes.

So with all that being said and in an attempt to spot trends in advance , a little bit of market research.


Would your own house be something that would be capable of having External Wall Insulation ? would you consider it and if not why ? Have you considered it? Have you got it?

 

[Paul_B]

Wouldn't like that if I was the other half of that semi. A step out from one house to another doesn't look good.

We're detached 70s bungalow with underneath garage and undercroft. It's got cavity insulation so not sure it needs the external insulation but might be something I'd consider if I could get a grant or it was m as cheap as cavity can be.

Also, not sure if I'd have to get rid of the chip render on the rear and side of the house first.

 

[Tengu]

Create damp and lack of materials honesty?

Why not put UPVC on an old building and be done with it?

After all, no one cares about keeping house value....

 

[TeeDee]

Wouldn't like that if I was the other half of that semi. A step out from one house to another doesn't look good.

We're detached 70s bungalow with underneath garage and undercroft. It's got cavity insulation so not sure it needs the external insulation but might be something I'd consider if I could get a grant or it was m as cheap as cavity can be.

Also, not sure if I'd have to get rid of the chip render on the rear and side of the house first.

The issue regarding profile levels and terraced/semi houses is something I've considered. And you are right , a street where every other or 3rd house will have a different profile is going to look a bit odd - In an ideal world ( we can dream... ) the entire street would be eligible for a grant or similar which I would hope lessen the impact somewhat.

 

[Paul_B]

Personally I think the government will have to pay to upgrade houses sooner or later. I think we've got some of the least insulated houses in Western Europe. Thar needs to change.

 

[TeeDee]

Personally I think the government will have to pay to upgrade houses sooner or later. I think we've got some of the least insulated houses in Western Europe. Thar needs to change.

And where do you think the money will come from for that. ?

 

[Stew]

Personally I think the government will have to pay to upgrade houses sooner or later. I think we've got some of the least insulated houses in Western Europe. Thar needs to change.

Ha ha!

Absolutely no chance!!

 

[Scottieoutdoors]

Personally I think the government will have to pay to upgrade houses sooner or later. I think we've got some of the least insulated houses in Western Europe. Thar needs to change.

I personally don't understand the view of government paying for everything.

I can see that if the gov keep introducing additional levys and taxes and various green initiatives, they're going to have to give people "help"....whether that come in the form of reduced planning loops, or buy now pay later initiatives, I guess that'll be left to be found out, but we don't live in a country whereby the state provides or even should provide for everything.

 

[Paul_B]

And where do you think the money will come for from that. ?

Absolutely no idea but with electricity demand vs generation going the wrong way energy demand reduction will make the cost- benefit ratio move in the right way to make this happen.

Out of interest, the way we're paying for the green initiatives now and the way they're not working well, is this any better than paying straight out of taxes instead and getting efficiency of scale by government paying for the work directly?

 

[slowworm]

It's something I need to look into. Living in a damp area I refuse to have cavity wall insulation added (despite the various government grants we get offered wrongly insisting on it).

Rather than expect the government to pay for it to be done I would like to see someone trustworthy produce a decent guide of what's available, what prep work needs to be done and what alterations may be required to things like the roof line.

By prep work I mean does the external render need to be in tip top condition of can the cladding be done over light cracking?

 

[Stew]

The issue regarding profile levels and terraced/semi houses is something I've considered. And you are right , a street where every other or 3rd house will have a different profile is going to look a bit odd - In an ideal world ( we can dream... ) the entire street would be eligible for a grant or similar which I would hope lessen the impact somewhat.

Is there a planning permission issue?
It would be increasing the external footprint of the building.

Also for some walls it could extend past the coverage of roof over hangs. What happens there?

 

[Stew]

Create damp and lack of materials honesty?

Why not put UPVC on an old building and be done with it?

After all, no one cares about keeping house value....

How would it create damp?

What insulation value does upvc have?

Im assuming the last comment is sarcasm?

 

[TeeDee]

Is there a planning permission issue?
It would be increasing the external footprint of the building.

Also for some walls it could extend past the coverage of roof over hangs. What happens there?

Good shout on the external foot print aspect.. hmmm... not sure.

I think with the 'HAT' Aspect of the roof it needs to be accommodated by extending the roofline - easier said than done or maybe some new fascia and soffit combination.


These are from a ( Soon to be certified ) Passive House I passed yesterday in my local Town

Whilst I can't see Passive Houses are for the majority there are some interesting points related to retrospective improvement of a dwelling - not all properties can take an ASHP , GSHP, MVHR , Etc etc but we do understand that increasing the roof insulation is something we all tend to do - so will EWI be the next thing?







You can see the Insulation extending out on the corner pushing the front of the house out.

What is a Passive House? [Passipedia EN]

passipedia.org

Certified Buildings Map

database.passivehouse.com

I'm just wondering if EWI is something we will see more and more of? In an attempt to improve Britains current housing stock?

 

[Scottieoutdoors]

Britain is a really problematic country for buildings.
The colder nordic nations have incredible insulation, but they're* typically very cold or warm. In the UK it's damp damp damp... a few weeks of dry summers now and again, then it's damp and cold all year round.

*the weather in those countries I mean...

 

[TLM]

There is no such thing as "passive" house. If the interior is warmer than the exterior energy has to come from somewhere. Here the trick is that lighting and warm water is not counted as "heating". Anyone believing such a thing to be "zero" heating energy should be stripped of any physics degrees.

Moisture (in the case of houses mostly defined as water in gas phase) travels towards lower water vapor pressure which usually means from warm to colder. If the outside is very warm that changes direction and things get slightly hairy. As far as I know nobody has developed a good PRACTICAL solution solution to that. I am fairly sure one exists in climates with no or very little freezing.

The governing physics is well known but practical solutions are far behind and the normal builder does not really understand all that unless specifically taught.

 

[Toddy]

It's the damp that's the issue.
Tengu's comment was appropriate because covering the building like that totally negates any moisture transfer through the walls....and that house looks to me like it has cavity walls.

Properly built, and maintained, that cavity insulates anyway but allows moisture flow.

Timber framed houses often have vapour barriers, and that's a whole other story in itself.

Basically folks need to understand the construction of their buildings, before they start trying to slap on whatever.

Round here we have a lot of sandstone houses. My Granny's cottage was simple sandstone block walls, and my Grandpa paid for damp proof coursing to be added later. Not quite a great success, the scullery was always damp, but then, it had a stone floor that was level with the ground outside.....again, understand the construction of your building.
Folks who own those old houses now, which had lathe and plaster inner walls round here for posh, but timber lined for common, complain about trying to insulate them.
It's a bit like trying to insulate a castle, tbh.
(As an aside, the stones came from local quarries, the price of a sandstone block, 2' x 1' x1' was three ha'pence in the early 1900's )

Our own house is brick built, with roughcast coating. Very common in the UK and very weatherproof.

Twenty years ago the Council offered cavity wall insulation, blown fibreglass iirc, and properly owners who signed up for it simply paid for it as an addition to their gas bills. I think the Gas Board administered the scheme.
It worked, it wasn't onerous, and the houses are warmer, and the walls still breathe and don't cause damp issues.
You can see the houses that don't have it when it's frosty. Their ice melts first.

I don't think there's one answer that fits all houses, is what I'm trying to say. Not in the UK, not in our damp and just above/just below freezing, climate.
Today's a case in point. It has poured the last two days, so everything's sodden wet. Today we have lovely gentle sunshine, but the air's cold, so little drying, and tonight it's supposed to drop to -3˚C.
Anything with moisture has trouble in that, and in our country, that's constant.

Honestly, the best solution we've found is little differences.
Insulate the floor of your loft.
Fit good windows and doors.
Insulate your floors from the crawlspace....hardboard sheets are most effective draught stoppers, but so are the recent fashion for wood look floor tiles.
If the heating is on, close interior doors.
Buy and use a decent dehumidifier, especially if you still dry clothes inside your home.
Keep your roof, rones and roughcast in good order and don't let water pool against your founds.

 

[TLM]

Timber framed houses often have vapour barriers, and that's a whole other story in itself.

I'll comment to this first as this is a common way of looking at things, it is not really wrong but not totally correct either, a plastic film or equivalent acts as a vapour barrier but primary function is air barrier and it is the air moving through walls that carries the water vapour (gas). In cold climates it is customary to have very slightly lower air pressure inside the house to prevent the air carrying the moisture into the wall as the barrie'll leak anyway (if otherwise ok, the electrician has pierced it anyway) .

A working solution to moisture inside the house is to have a dehumidifier but to really work that requires a very good air circulation inside, something old houses usually do not have.

One known way to fight moisture in the walls is to have outside cladding that does not let any outside water into the wall and lets the moisture from inside to escape beneath it.

 

[Toddy]

So, our traditional roughcast/harling then ?

 

[TLM]

So, our traditional roughcast/harling then

(Starting with a dictionary )

It does depend what is underneath that plaster, here plaster is commonly done (last 15 years) on very hard mineral wool that has machined grooves in it. That layer is actually slightly ventilated just to enable the drying of outside water (rain, sleet, snow ...) and what little comes from the inside.

The same or slightly better can be achieved with water proof cladding that is well ventilated underneath (not too well), that keeps water away and also cools the building under sunshine.

Lately some plasters are treated with a water repellent, like some outdoor clothing. Works but quite expensive and has a limited life time.

Then there is of course the old Hungarian solution: make the walls out of unbaked clay. Often have double row of cavities and also seem to have an almost unlimited capacity for absorbing moisture and then releasing it. The longer the eaves the better.

 

[Scottieoutdoors]

It's threads like this that make me really see the attraction to just living in a cave with a fire for warmth...