Insulate Britain

[Lurker]

This is not a political post so don’t turn it into one.

IMHO if you over insulate, ie block up every conceivable gap, what about condensation build up and what about ventilation for combustion.
Also some of the payback times are donkey’s years and I sometimes wonder if these even take into account of the fact that at least half of the year there is no heating on so the various systems are “idling “.

Loft insulation is a no brainier, but I am sceptical about the rest unless it’s part of a rebuild.

Interested in what others think.

 

[Malc2098]

Way back in the 80s, I had the cavities of my 3 bed semi near High Wycombe filled with rockwool. It was completed on Christmas Eve. The difference was noticeable instantly. The CH thermostat had to be lowered that night.

 

[Lurker]

Way back in the 80s, I had the cavities of my 3 bed semi near High Wycombe filled with rockwool. It was completed on Christmas Eve. The difference was noticeable instantly. The CH thermostat had to be lowered that night.

That doesn't make sense. The thermostat was measuring the room temperature that it was set at, irrespective of heat input and heat loss.

 

[novocaine]

I paid 3k 2 years ago to have incorreclty installed cavity wall insulation removed because the warranty didnt cover removal due permeable brick apparantly. The house became warmer and the damp issue disappeared as there was no longer a bridge between the leafs.

Im fine with it on a new build with .modern bricks and a cavity between the 2 leafs still (as our extension is) Otherwise it was a massive con akin to injection damp proofing, there may have been reputable installers, but their were considerble more cowboys who'd take your money and run.
Loft insulation is a no brainer, as is decent windows, but old houses were designed around ventilation and sealing them up is a short term gain for a long term loss.

 

[MattS]

It's a massive issue to solve. No viable alternative to gas at scale and current housing stock needs a lot of heat due to low insulation.

One thing I am certain on, I see no reason why we are still building brick houses with a cavity, modern houses should be built using better techniques. I have a big interest in sustainable building, another thing to consider is the materials we use, our building industry is so reliant on cement and gypsum both of which are bad materials.

 

[Woodster]

It’s a interesting topic. A TV series called “House for the Future” aired in the UK in 1976 and I found it very interesting. Even back then the importance of good insulation was well recognised. Scandinavian countries in particular were given as an example. Many houses in Sweden where the temperature regularly gets down to minus 25c didn’t even have central heating so the programme said, they just had small electric heaters in the bedrooms if it got really cold. I’m not a scientist but I’ve seen it stated several times that if we used proper insulation in new builds together with triple glazing we wouldn’t need conventional gas boilers as it simply doesn’t get cold enough in the UK to warrant them? So it seems we still don’t insulate properly in the UK? Is the cost of insulation really that prohibitive these days - I’ve never bought any. How high do gas prices need to go to make it more attractive?

As an alternative to using gas I happened to see this the other day so I guess they do need heating in those countries after all!?

https://energymonitor.ai/sector/heating ... -in-europe

Even with the Internet, finding the truth these days is getting harder. I do know though that if it’s cold outside putting a coat on keeps me warmer.

 

[AJB Temple]

It's an interesting one. We live in what is mainly an old barn, which was converted by someone else, not brilliantly well, 40 years ago. I have added a very large kitchen with a lot of glazing on the south side, a large larder and side kitchen room, and an oak framed music room. All three of these exceed by a considerable margin the current requirements for building regs wrt insulation. To get anywhere close to this in the rest of the old house, apart from the lofts, would be nigh on impossible whatever the insulation protesters think. It would require me to add another skin to the outside of the house (with difficulties in roof overhangs), or to the inside - easier but we lose a lot of room space.

To get older houses up to modern standards, let alone passive house low energy consumption standards, is a very difficult, extremely expensive and impractical job in many cases.

I've not really followed the protests but I think they relate mainly to social housing. I can't see fundamental change happening as social housing is typically council or housing association owned, and they have little incentive to do upgrades. We should focus on far better designs for new builds but planning and regs tend to establish a lowest common denominator rather than standards to aspire to.

Modern factory panel building methods lend themselves to high levels of insulation, but this is not the cheapest way to build.

 

[Malc2098]

Way back in the 80s, I had the cavities of my 3 bed semi near High Wycombe filled with rockwool. It was completed on Christmas Eve. The difference was noticeable instantly. The CH thermostat had to be lowered that night.

Take it up with my ex-wife. I just checked with her that we felt a difference that night, and that's what she said.

The house was a late 60s semi. No question, we used the CH much less after it was installed.

 

[AndyT]

Lurker, I share your concern. Just sealing up old houses without adding a proper ventilation system is a recipe for condensation and mould. I do hope we don't get ill-planned schemes that will make things worse.

Coincidentally, Roger Bisby published a rant about this a few days ago on his YT channel. He linked to this blog, which I've not read yet, which explains what good practice and Passiv Haus building do to control ventilation in well insulated and air controlled houses:

https://elrondburrell.com/blog/passivha ... struction/

Looks worth reading.

 

[Phil Pascoe]

Way back in the 80s, I had the cavities of my 3 bed semi near High Wycombe filled with rockwool. It was completed on Christmas Eve. The difference was noticeable instantly. The CH thermostat had to be lowered that night.

Take it up with my ex-wife. I just checked with her that we felt a difference that night, and that's what she said.

The house was a late 60s semi. No question, we used the CH much less after it was installed.

As you would - but altering a thermostat had nothing to do with it. The boiler just wouldn't run for as long.

 

[Trevanion]

Built an outdoor room this year which has 5" celotex in the floor, walls, and ceiling with double glazed bi-folding doors on one side and end. No word of a lie, one person just breathing in there with everything shut is enough to make the room uncomfortably warm, installing a gas fire was a mistake :lol:

I think some of IB's points make sense, but others are outright unfeasible. But it isn't like the government isn't doing anything about the problem, there have been grants for years to insulate eligible homes and even retrofit a complete central heating system, someone I know recently had all the above done completely free of charge as they had no insulation and were heating with a coal-fired AGA. The only realistic way to achieve IB's goal of making all homes thermally efficient would be to knock down something in the region of 10-million homes and rebuild them better, which would cost the country trillions!

My main concern is that while they're prancing about on the motorway they're going to come across the one fella who's having a bad day as it is who might feel his foot getting heavier (as we've seen other times with protesters in France, the USA, India, and so on...), it would be a shame for someone to end up as a mile-long smear on the motorway over something quite silly really.

 

[MattS]

it would be a shame for someone to end up as a mile-long smear on the motorway over something quite silly really.

I think they’d say and I’d agree that we have gone spectacularly beyond it being a bit silly and we’ll into the collapse of nature, mass extinction and conflict as a result of climate change. A few grants isn’t enough

 

[Lurker]

Come on chaps I did ask to keep it non political.

Can we stick to the practicalities and the pros and cons of insulation.

 

[sunnybob]

Way back in the 80s, I had the cavities of my 3 bed semi near High Wycombe filled with rockwool. It was completed on Christmas Eve. The difference was noticeable instantly. The CH thermostat had to be lowered that night.

Take it up with my ex-wife. I just checked with her that we felt a difference that night, and that's what she said.

The house was a late 60s semi. No question, we used the CH much less after it was installed.

Quite feasible.
If the heat loss through the walls was great enough, the boiler would never be able to get the room temp up to the stat setting. Once the insulation was installed, for the first time ever, you actually got the set temp, which turned out to be too hot. Reducing the stat made the room temp actually match the set temp.

I had my 60's brick built 3 bed semi rockwool insulated in the late 70's. It made a tremendous difference. With 2 young children to look after the house was warm and pleasant with only a wall mounted gas fire down stairs, and a single flame wall mounted gas heater on the upstairs landing.

A 5 bed detached I owned in the early 2000s, I had polystyrene beads used on the one long brick wall. But I did install C/H in that one.

Out here, the houses are concrete reinforced shells, with clay block walls cemented over. but Cyprus has now upped the ante and all houses occupied for the first time must be fitted with blue celotex wall panels on the outsides, which is them cemented over again.

 

[RogerS]

The ONE person on this forum who is qualified to talk about this is MikeG.

Old housing stock does not lend itself to becoming more energy efficient. Despite what the pond scum (question...are they related to KDOS ?) with their vanity project think.

 

[AndyP]

How much of it is too old for retrospective insulation I wonder.

I also wonder why the, possibly, thousands of acres of rooves on public buildings are not covered in some sort of solar energy devices.

 

[Trevanion]

it would be a shame for someone to end up as a mile-long smear on the motorway over something quite silly really.

I think they’d say and I’d agree that we have gone spectacularly beyond it being a bit silly and we’ll into the collapse of nature, mass extinction and conflict as a result of climate change. A few grants isn’t enough

Sorry, I think you might've misinterpreted what I meant by "over something quite silly".

I think climate change and conservation are very important issues and we should be doing more to protect what we've got here, what I think is silly is extreme acts such as gluing yourself to the road. It does the cause no favours and creates more animosity, and as I said, someone is going to get killed with the road rage and whacky driving maneuvers to go around the protesters I've seen in some videos, and I think people have every right to be miffed at protesters.

Anyway, back to insulation...

Our front room is in the older part of the house (I'm not quite sure how old exactly the old part is, supposedly it dates from the Georgian era) which has slate walls that are about 2-3ft thick, the outside wall was always bloody freezing in the winter so a few years ago we ripped the plasterboard that was dot and dabbed onto the slate off and studded it out and put some Celotex in the studding, it made a massive difference to the temperature of the room and it didn't require half as much heat to keep warm. Fortunately, the room was large enough you didn't feel like you lost loads of space but you definitely lost a fair amount so this would be a non-starter for some homes.

Another thing as a joiner that bugs me it that the heritage trusts in charge of the listed buildings are absolutely dead-set on keeping them as thermally inefficient as possible. We'll be doing a job soon for a grade 2 listed building that needs to be single-glazed throughout, now, the building is nothing special and is really a glorified cow-shed in appearance and there have been several iterations of windows installed over the years from the original sliding sashes that are lifted manually and pegged in place rather than weight balanced, to very modern 1980s Jeldwen-style windows, but they are insistent on replicating the original single glazed ones. If you were to put a double glazed window in the exact same style as the originals next to the originals, barely anyone is going to notice the difference, especially with the newer 12mm slimline units and soon the 6mm vacuum units. I appreciate that we don't want to be putting aluminium or PVC windows in a 300-year-old house, but we can improve the building's viability as an efficient home while still being sympathetic to it's original appearance with very little to no visual difference.

 

[PAC1]

Another thing as a joiner that bugs me it that the heritage trusts in charge of the listed buildings are absolutely dead-set on keeping them as thermally inefficient as possible.

There is an English Heritage guide on energy efficiency in old buildings and listed buildings. It is excellent. It advocates for insulation and shutters or double glazing. The issue they say is to identify the elements of the listing that warranted the listing and then look at upgrading as long as it does not fundamentally undermine those elements.
10 years ago a conservation officer told me that the way to live in a listed building was to enjoy it in the summer but in the winter just live in one or two rooms and shut up the other rooms. I now have double glazing in my timber frame grade II listed building and insulated walls. The latter with full assistance from the current conservation officer who identified the appropriate type of insulation to use.

 

[Mike G]

Way back in the 80s, I had the cavities of my 3 bed semi near High Wycombe filled with rockwool. It was completed on Christmas Eve. The difference was noticeable instantly. The CH thermostat had to be lowered that night.

That doesn't make sense. The thermostat was measuring the room temperature that it was set at, irrespective of heat input and heat loss.

It does make sense, Jim.

Room thermostats are a switch for automatically turning the heating on. Human perception of comfort isn't just about the air temperature, but about whether the air is moving or not, and whether there are temperature differences in a room (draughts). A still room at 21 Celcius feels a lot warmer than a draughty room which is at the same temperature. We naturally adjust the thermostat to allow for draughts, so a draughty room will have the thermostat set higher than a non-draughty one. Insulation can reduce draughts not just by blocking up gaps which shouldn't be there, but by increasing the temperature of the inner faces of external walls. If all the surfaces in a room are nearer to the average in the room, then eddies aren't set up, because there will be less air cooled by cold surfaces.

Insulation should never be looked at in isolation from ventilation. Sealing and insulating a house is no problem at all (it's a huge bonus, actually) so long as ventilation is properly allowed for. What you are really doing is swapping uncontrolled incidental ventilation (draughts) for well controlled ventilation. The ideal, and something I have fitted to every project I've been invovled in for the last 25 years, is mechanical ventilation with heat recovery, which simply means that there is a constant turn-over of air in the building, but that the incoming fresh air is pre-warmed using the heat taken from the outgoing stale air. It produces the most pleasant indoor environment imaginable, where there is never any condensation and no stale smells. Accompanied by proper levels of insulation and decent glazing, such a house can have heating bills under £100 annually.

 

[AndyT]

Thanks Mike. The gap in my experience is what that "mechanical ventilation with heat recovery" system looks like. If it needs ducts and grilles in every room, leading to a central unit in the loft, is it possible to retrofit into say, millions of small Victorian terraced houses?

 

[novocaine]

hay, what we should do right, and this is really important, is ignore the amount of energy required to make our plastic based or glass/mineral based insulation and instead claim we are saving the planet by using as much of this stuff as possible. even better if we make it so you have to change it every 10 years (loft insulation). OK glass fibre is recyclable, just not in the UK.

not mentioning the hundreds of tons of CO2 produced during the process.

shhh, don't tell anyone.

sustainable goals are easy if you put the burden on another country. (sorry, that was political)

edit to add, this makes me sound like I'm not interested in reducing energy wastage or co2 etc. which couldn't be further from the truth, it just needs to be done right. heat recovery and pragmatic insulation is viable, just wish it wasn't so damned expensive to implement.

 

[Mike G]

Thanks Mike. The gap in my experience is what that "mechanical ventilation with heat recovery" system looks like. If it needs ducts and grilles in every room, leading to a central unit in the loft, is it possible to retrofit into say, millions of small Victorian terraced houses?

That's a fair description of MVHR systems in new build houses, Andy. Retro-fitting, though, can use a somewhat simpler and cruder system, sometimes integrated into a cooker hood, sometimes a unit in the loft at the head of the stairs. Generally it's fairly easy to retro-fit to properly cover the upstairs rooms (the bathroom being the most important), but have a somewhat simpler approach downstairs, treating it as one space rather than trying to cover each room individually.

 

[Mike G]

hay, what we should do right, and this is really important, is ignore the amount of energy required to make our plastic based or glass/mineral based insulation and instead claim we are saving the planet by using as much of this stuff as possible........

Yep, that's right. Because the amount of energy used in making the insulation is utterly trivial when compared with the amount of energy they save over their lifetime. There are perfectly good insulators made from recycled paper or from wool, if embodied energy really is your primary concern.

 

[novocaine]

hay, what we should do right, and this is really important, is ignore the amount of energy required to make our plastic based or glass/mineral based insulation and instead claim we are saving the planet by using as much of this stuff as possible........

Yep, that's right. Because the amount of energy used in making the insulation is utterly trivial when compared with the amount of energy they save over their lifetime. There are perfectly good insulators made from recycled paper or from wool, if embodied energy really is your primary concern.

payback on energy saved in a typical house from blown fibre insulation is around 5-8 years. worst case is 20GJ of energy input per tonne of insulation (5555kwh). DECC research suggests a saving of 400kwh/y for loft insulation so 13-15 years pay back if you have have a big house. but that's per house so we need to look at how many houses can be insulated per tonne of material (I'm ignoring energy for shipping etc.), so a 10x10m loft requires 189kg of insulation for 270mm, so 5 homes per ton on average, so pay back is 3 years. really simplistic though as it ignores other energy requirements, which could extend that 5 years to more like 8, so it's a close run thing if you replace it when you apparently should and it doesn't sound quite so trivial to me.

should you insulate your home, hell yes, should you look at other products beyond the current mainstream, even more yes.
one should always show your sources.

https://ec.europa.eu/clima/sites/clima/ ... ool_en.pdf

https://assets.publishing.service.gov.u ... art_II.pdf

still stand by my statement though, being energy efficiency shouldn't cost you more then not being.

 

[Mike G]

I'd need a source for the requirement to replace insulation every 10 years, because I have literally never heard anything like that in my life. I can't begin to imagine why that would be the case, other than a great marketing exercise for the suppliers.

 

[Mike G]

worst case is 20GJ of energy input per tonne of insulation (5555kwh). DECC research suggests a saving of 400kwh/y for loft insulation so 13-15 years pay back if you have have a big house. but that's per house so we need to look at how many houses can be insulated per tonne of material (I'm ignoring energy for shipping etc.), so a 10x10m loft requires 189kg of insulation for 270mm, so 5 homes per ton on average, so pay back is 3 years.

Three years using the worst-case figures. One third of that using the best case figures. A one year energy payback period is, I say again, trivial. No matter what the suggested replacement period is, the actuality is that people aren't replacing their loft insulation every 10 years. Even if they were, investing 1 joule of energy to save 10 is a decent return, but if the reality is two, three, five times that then it really isn't even a conversation worth having.

 

[novocaine]

3 years using best case figures not worst case and ignoring a vast swath of ancillary energy associated with the process. Trivial isn't the right word.

although we do seem to be arguing the same side of the coin here Mike.

 

[Lurker]

This is now getting interesting.
Regarding the paybacks, using loft insulation as an example I fully accept that the payback is measured in relatively few years, but a year is actually less than six months as that’s when I use energy to warm my house.
The warmer months the insulation is doing nothing for my energy bill.
So….. do figures take this into account?

 

[droogs]

This is now getting interesting.
Regarding the paybacks, using loft insulation as an example I fully accept that the payback is measured in relatively few years, but a year is actually less than six months as that’s when I use energy to warm my house.
The warmer months the insulation is doing nothing for my energy bill.
So….. do figures take this into account?

Technically not quite right as the insulation will help prevent the house getting hotter and therefore lower consumption by not having a fan or AC on as much. Insulation works both ways

 

[Woodster]

I realise that it reduces room sizes slightly but I’ve often wondered how well insulated plaster board works? The stuff I saw had about 25mm of polystyrene foam on the back?

 

[Lurker]

This is now getting interesting.
Regarding the paybacks, using loft insulation as an example I fully accept that the payback is measured in relatively few years, but a year is actually less than six months as that’s when I use energy to warm my house.
The warmer months the insulation is doing nothing for my energy bill.
So….. do figures take this into account?

Technically not quite right as the insulation will help prevent the house getting hotter and therefore lower consumption by not having a fan or AC on as much. Insulation works both ways

Yeh I understand that, but I have no need for either.

 

[Mike G]

I realise that it reduces room sizes slightly but I’ve often wondered how well insulated plaster board works? The stuff I saw had about 25mm of polystyrene foam on the back?

It's impossible to look at this in isolation. It entirely depends on the build-up of the wall. Sometimes, where an insulation is in the wall is more important than what it is or even how thick it is. What can be said, however, is that it being attached to plasterboard is only for convenience, rather than for energy efficiency or improved performance. You would get precisely the same result by fixing 25mm of the same insulation to the wall, and covering it with plasterboard, assuming you could fix everything without gaps. I'm not a great believer in polystyrene, BTW, because it can be an issue in a fire (I know there are various types).

 

[AJB Temple]

Also worth noting that plasterboard with insulation attached is amazingly expensive - much more when I last costed it, this year, than buying the board and insulation separately. Maybe it saves some construction time on big builds, but for DIY it makes little sense to use it.

 

[novocaine]

apparently our discussions are being monitored.

https://www.bbc.co.uk/news/science-environment-58667328

 

[wallace]

I converted my loft into a hobby room and insulated the roof and floor. This had a big impact on the warmth of the house. My house is the last to loose its snow covering in the winter. I also insulated the cavity. The problem I have now is during warm periods my wife puts the heating on. I keep saying open a window to let some heat in.

 

[Lurker]

apparently our discussions are being monitored.

https://www.bbc.co.uk/news/science-environment-58667328

The on going cause is the way vat is applied.

I used to live in the far north of Scotland. Everywhere there were really nice but ramshackle stone houses with a fair amount of land going for a song. People bought the plot and put a new build on it.
I couldn’t understand why, until it was explained to me that the new build was vat free but to do up the more visually attractive building would incur vat.

 

[Phil]

Just a comment on some insulation from way down South ….

Our first house we purchased in 1975 was about 25 years old.

First action was to take down the chimney, seal it off in the roof, fireplaces are messy and that elusive ‘someone’ has to clean it. The fireplace was also in the dining room, not very practical.

Next was to insulate the ceiling. I used 50mm Think-Pink fibre glass insulation. What a difference it made to the temperature inside the house. Just so much cooler in the summer heat and warmer when we went into the first winter. We are not great fans of heaters.

In May 1981 we moved into our second house which we designed and had built. When winter arrived it was the ideal time to insulate as the roof cavity was a lot cooler. Again 50mm Think-Pink as that what was on offer.

After doing the first house I was more geared up for this one.
Laid some nice thick pine planking across the rafters end to end. The roof had 2 pitches and even the low side was high enough to stand upright.
A wide crawling board with batons so that it could slide between the rafters. Made crawling to the low edges easy.
The same effect of cooler in summer and warmer in winter.
The ‘insulation boy’ was then asked to do the parents house. What could I say, of course, just stock up the beer supply.

Move on to 2014 when we signed off the plans for our new house in the retirement estate.

By now the Gov had woken up to energy saving and energy efficient houses.

The ceiling has 100mm green stuff (don’t think its fibreglass) and the ceiling itself is Rhino Plasterboard.
The water pipes are all insulated and the geyser should have a blanket.

We have SABS SANS 204:2011 as the set standard
There is a heat pump for hot water to the geyser, the element is switched off and will only be used if the pump fails. The building choice was heat pump or solar panel geyser which has a small circulating pump.
The hot water pipes in the roof are connected in a ‘ring’ to supposedly supply the best hot water flow.

In the design we were allowed to change a number of items except the outside walls on foundation. It is a raft foundation.

So we decided to remove the 3 bedroom windows and replace with nice big sliding doors to bring lots of light into the house.

In the living room we also removed the West and North windows and replaced with large stacking doors, again to bring more light into the house.

Now as part of SABS SANS 204-m the m2 of the windows area is measured against the total floor area including the garage. If it exceeds 15% which in our case worked out to 20.75%, then special glass needs to be fitted (costly exercise but worth it).
The glass is called Low-E and is treated with a chemical which reflects the heat out and retains the heat in. Fantastic idea. (see the gripe later on!)
To this we also had sun-shield film installed on the sliding and stacking doors for more heat protection and UV minimisation. Also provides some privacy, not easy to see into the rooms.

All this expensive glass is installed in bronze aluminium frames, the standard set for the estate.
Really looks great when new and then starts fading.

BUT! The gripe ……………………..

In summer the aluminium frame gets so hot you can’t even touch it and all that heat goes straight into the house negating any benefits of the insulation and Low-E!
In winter just the opposite - the frame gets as cold as the outside temperature (this last winter we had had lots of 4c days) so again negating a lots of the so-called energy benefits.

Conclusion - the people who compile these standards, great idea, probably only deal with laboratory conditions .

 

[RogerM]

BUT! The gripe ……………………..
In summer the aluminium frame gets so hot you can’t even touch it and all that heat goes straight into the house negating any benefits of the insulation and Low-E!
In winter just the opposite - the frame gets as cold as the outside temperature (this last winter we had had lots of 4c days) so again negating a lots of the so-called energy benefits.

Phil - I'm really surprised that there isn't an effective thermal break in the frames, because as you say, heat will flow downhill in either direction. Do you have a condensation problem on the internal frames on a cold day too?

I remember our first house in 1978 was an old red sandstone cottage near Penrith with absolutely zero insulation in the loft. We got a grant to insulate it with 4^ of fibreglass. I started out working in the loft on a bitterly cold day in my shirtsleeves, and by the time I'd finished I had to put on a thick sweater, the difference was so marked. The ceiling under the flat roof bedroom extension above the garage was inaccessible, and clearly lacked insulation of any type, but luckily we were newlyweds so keeping warm wasn't a problem :lol: .

 

[Mike G]

Last time I was in SA it was barely possible to get double glazing, and virtually no-one had it. My house here is triple glazed, with timber window frames. The level of insulation, too, is in stark contrast to yours. New builds here will have at least 250mm of fibreglass in the loft, and if they have a large window area then this will be bumped up to well over 300.I've got 500mm in mine......and the equivalent of 300mm in my walls, compared with the normal 100mm. SA has such high levels of sunlight (never mind the temperature), that it would be child's play to design houses that had no heating or cooling requirements. I say again....no need for heating or air conditioning. I've pulled my hair out trying to persuade people in your wonderful country that this is not only easily (and cheaply) attainable, but also a target worth aiming at.

 

[RogerM]

BUT! The gripe ……………………..
In summer the aluminium frame gets so hot you can’t even touch it and all that heat goes straight into the house negating any benefits of the insulation and Low-E!
In winter just the opposite - the frame gets as cold as the outside temperature (this last winter we had had lots of 4c days) so again negating a lots of the so-called energy benefits.

Phil - I'm really surprised that there isn't an effective thermal break in the frames, because as you say, heat will flow downhill in either direction. Do you have a condensation problem on the internal frames on a cold day too?

I remember our first house in 1978 was an old red sandstone cottage near Penrith with absolutely zero insulation in the loft. We got a grant to insulate it with 4^ of fibreglass. I started out working in the loft on a bitterly cold day in my shirtsleeves, and by the time I'd finished I had to put on a thick sweater, the difference was so marked. The ceiling under the flat roof bedroom extension above the garage was inaccessible, and clearly lacked insulation of any type above the ceiling or in the floor separating us from the garage below, but luckily we were newlyweds so keeping warm wasn't a problem :lol: .