But I think solar makes a lot of sense if you can keep the install cost
right down. eg if you go here: https://www.cityplumbing.co.uk/content/solar-pv-kit-builder
and price up a 5kWp system it's about £1200-1500 in materials.
If you can DIY and you can keep roof access cheap, then that reduces the payback time to a few years even with the most pessimistic assumptions and making no attempt to optimise your consumption.
Rule of thumb is that every kWp generates 1MWh over the year.
system would generate 5000kWh per year, and even if you only used a small percentage of that optimally then payback would only be a few years if you were able to DIY the install (or contract out the minimum that you need help with and DIY the rest).
Theo
In message <14s*uDl3z@news.chiark.greenend.org.uk>, at 17:50:09 on Mon,
30 Dec 2024, Theo <theom+news@chiark.greenend.org.uk> remarked:
I think a big unknown is the pre-WWI houses - single skin brick,
suspended
wooden floors, designed to be heated with a big coal fire running
constantly. Some decent internal wall insulation would likely help a lot >> there, but it's quite disruptive.
Go steady with the "single skin brick", it's usually not a skin of
single bricks, but double thickness. As a result when I've had such
houses (and some older ones had even thicker walls) I've never felt
that the leakage through the walls was significant.
On 30/12/2024 12:00, Theo wrote:
But I think solar makes a lot of sense if you can keep the install cost right down. eg if you go here: https://www.cityplumbing.co.uk/content/solar-pv-kit-builder
and price up a 5kWp system it's about £1200-1500 in materials.
I'm seeing 11 panels @ £50, inverter £700, £1,800 ex VAT total.
Rule of thumb is that every kWp generates 1MWh over the year.
Energysavingtrust suggests less than that even in the South East.
On 30 Dec 2024 at 12:26:57 GMT, Theo wrote:
RJH <patchmoney@gmx.com> wrote:
Fair enough! Be interesting to see how it ends up in a couple of years.
My sister had a heat pump installed in her pre-Victorian 5 bed detached house.
Seemed unlikely to me. I've asked her (and her environmental scientist
husband) a few times about before/after costs. They don't seem to know - they
just say it's fine, and pay the bills.
Look up their gas+elec kWh consumption if you put in their postcode here:
https://energy.which.co.uk/
(just click through to accept all the defaults)
and you can tell us what their usage looks like compared with their
neighbours.
Doesn't work for her address for some reason - asks me to input the figure (tried some variations around the defaults).
Some *very* peculiar readings around me. Mine's pretty much accurate, but some
are from an educated guess wild underestimates - some are even negative.
My immediate neighbours use over 3 times the gas, and double the electric, to me. Says something about someone :-)
Theo of this group seems to be doing some pretty thorough analysis, but the >>> problem for me is transferring his experience to others.
Every house is different. But mine's pretty average - typical 1960s
construction, no attempt at insulation made in the build. The usual
upgrades have been made that most people have (90s UPVC double glazing, 90s >> cavity wall insulation, 100mm fibreglass loft insulation). Because it has a >> 1970s loft conversion it is harder to insulate than regular houses (eg 80mm >> fibreglass wool behind the loft walls, loft height restrictions means
putting in 300mm of insulation is not feasible due to only having crawl
access),
100mm of PIR maybe?
and the loft is very very leaky (the location is exposed and the
wind blows through every gap). So the message is that it works for bog
standard boring houses, you don't need a fancy super insulated eco home to >> benefit.
OK thanks, yes. I think an additional issue with older homes is damp, especially to the ground floor, where the building is constantly drying out due to partially failed DPMs. No evidence mind, just a guess.
Theo wrote:
If you don't use a lot of power to begin with, generating your own
seems less attractive.
An immersion heater would soak-up surplus PV output, better than
exporting it at SEG pittance rates?
Rule of thumb is that every kWp generates 1MWh over the year.
The economies of SMR are massively affected by toiw factors.
Proximity and regulation.
The Natural Philosopher <tnp@invalid.invalid> wrote:
The economies of SMR are massively affected by toiw factors.
Proximity and regulation.
I would suggest there is also third factor: security.
#Paul
Nick Finnigan <nix@genie.co.uk> wrote:
On 30/12/2024 12:00, Theo wrote:
But I think solar makes a lot of sense if you can keep the install cost
right down. eg if you go here:
https://www.cityplumbing.co.uk/content/solar-pv-kit-builder
and price up a 5kWp system it's about £1200-1500 in materials.
I'm seeing 11 panels @ £50, inverter £700, £1,800 ex VAT total.
How are you getting £700 for the inverter? A 4.6kW Growatt string inverter is £388, and the smaller ones are £150-300. None of their string inverters are over £400.
If you go for a hybrid inverter then they're £600+, but those are
designed for also charging battery storage.
Rule of thumb is that every kWp generates 1MWh over the year.
Energysavingtrust suggests less than that even in the South East.
https://globalsolaratlas.info/map?c=49.470102,0.186768,7&s=51.186949,0.351563&m=site&pv=small,180,38,1
a random location in Kent with a 1kWp due-south array at 38 degrees
generates 1027 kWh/year.
https://globalsolaratlas.info/map?c=53.787672,-0.944824,7&s=55.838768,-4.416504&m=site&pv=small,180,38,1
a random location near Glasgow generates 865 kWh/year.
Depending on your inclination and azimuth it'll be different, eg for Glasgow facing due east it's 654 kWh/year. Due north it's 420 kW/year. But they're still not a million miles from the ballpark figure.
On 31/12/2024 06:29, Roland Perry wrote:
In message <14s*uDl3z@news.chiark.greenend.org.uk>, at 17:50:09 on
Mon, 30 Dec 2024, Theo <theom+news@chiark.greenend.org.uk> remarked:
I think a big unknown is the pre-WWI houses - single skin brick, >>>suspended wooden floors, designed to be heated with a big coal fire >>>running constantly. Some decent internal wall insulation would
likely help a lot there, but it's quite disruptive.
Go steady with the "single skin brick", it's usually not a skin of
single bricks, but double thickness. As a result when I've had such
houses (and some older ones had even thicker walls) I've never felt
that the leakage through the walls was significant.
Ice box, especially if there is a gable end that is exposed to
significant wind chill too.
Then those huge fire places and
chimneys act like massive reverse radiators, sucking heat out
of the 'thermal envelope' and emitting it out through the
exposed chimney up above the roof line while the internal
flue stacks conduct heat out of the heated space into the
(uninsulated) section of the wall.
Barely an inch of PIR internal insulation would reduce the
heat loss to that of a 1970's cavity that had been insulated with
rockwool, ignoring the massive heatloss caused by fireplaces
and chimneys.
If these are still present then external wall
insulation would be more effective, even more so if the
above-roof chimney could be removed together with the
section of flue inside the unheated loft.
On 31/12/2024 06:29, Roland Perry wrote:
it's usually not a skin of single bricks, but double thickness. As a >>result when I've had such houses (and some older ones had even thicker >>walls) I've never felt that the leakage through the walls was
significant.
Oh, but it is significant.
Do the sums.
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter
if its single brick.
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter
if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
In message <vl0hjd$26pnn$2@dont-email.me>, at 10:38:37 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
it's usually not a skin of single bricks, but double thickness. As a
result when I've had such houses (and some older ones had even thicker
walls) I've never felt that the leakage through the walls was
significant.
Oh, but it is significant.
Do the sums.
Sums need formulae, and lots of assumptions.
I am of the opinion that
the thermal inertia of a solid wall compensates for most of the lack of
a layer of insulation.
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter
if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter
if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK house has 4.5" single skin external walls.
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter
if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
You might want to revise that opinion! Just 50mm of PIR can make a huge difference. I lined a north facing bathroom wall with it, and it went from theEven 3mm of cork was enough to strop condensation on kitchen and
coldest to the warmest room in the house.
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter
if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK house has 4.5" single skin external walls.
In message <vl0hjd$26pnn$2@dont-email.me>, at 10:38:37 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
it's usually not a skin of single bricks, but double thickness. As a
result when I've had such houses (and some older ones had even
thicker walls) I've never felt that the leakage through the walls
was significant.
Oh, but it is significant.
Do the sums.
Sums need formulae, and lots of assumptions. I am of the opinion that
the thermal inertia of a solid wall compensates for most of the lack of
a layer of insulation.
In message <vl1be7$29akv$2@dont-email.me>, at 17:59:34 on Tue, 31 Dec
2024, Andrew <Andrew97d@btinternet.com> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
In message <14s*uDl3z@news.chiark.greenend.org.uk>, at 17:50:09 on
Mon, 30 Dec 2024, Theo <theom+news@chiark.greenend.org.uk> remarked:
I think a big unknown is the pre-WWI houses - single skin brick,
suspended wooden floors, designed to be heated with a big coal fire
running constantly. Some decent internal wall insulation would
likely help a lot there, but it's quite disruptive.
Go steady with the "single skin brick", it's usually not a skin of
single bricks, but double thickness. As a result when I've had such
houses (and some older ones had even thicker walls) I've never felt
that the leakage through the walls was significant.
Ice box, especially if there is a gable end that is exposed to
significant wind chill too.
If and if. Possibly also "If the loft isn't insulated" too.
Then those huge fire places and
chimneys act like massive reverse radiators, sucking heat out
of the 'thermal envelope' and emitting it out through the
exposed chimney up above the roof line while the internal
flue stacks conduct heat out of the heated space into the
(uninsulated) section of the wall.
Barely an inch of PIR internal insulation would reduce the
heat loss to that of a 1970's cavity that had been insulated with
rockwool, ignoring the massive heatloss caused by fireplaces
and chimneys.
Huh? Why are you ignoring that. One answer is not to still have "big fireplaces", and either block them off or use wood (multifuel) burner
design.
On 02/01/2025 18:02, RJH wrote:
You might want to revise that opinion! Just 50mm of PIR can make a hugeEven 3mm of cork was enough to strop condensation on kitchen and
difference. I lined a north facing bathroom wall with it, and it went
from the
coldest to the warmest room in the house.
bathroom exterior walls...
On 02/01/2025 15:46, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec 2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter
if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
No cavity= single brick
Andrew <Andrew97d@btinternet.com> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
As a result when I've had such houses (and some older ones had even
thicker walls) I've never felt that the leakage through the walls was significant.
Ice box, especially if there is a gable end that is exposed to
significant wind chill too.
If and if. Possibly also "If the loft isn't insulated" too.
On 02/01/2025 15:46, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec 2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter
if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
No cavity= single brick
On 02/01/2025 15:40, Roland Perry wrote:
In message <vl0hjd$26pnn$2@dont-email.me>, at 10:38:37 on Tue, 31 Dec >>2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
it's usually not a skin of single bricks, but double thickness. As
a result when I've had such houses (and some older ones had even >>>>thicker walls) I've never felt that the leakage through the walls
was significant.
Oh, but it is significant.
Do the sums.
Sums need formulae, and lots of assumptions. I am of the opinionOh dear.
that the thermal inertia of a solid wall compensates for most of the
lack of a layer of insulation.
You haven't a clue, have you?
On 2 Jan 2025 at 15:40:26 GMT, Roland Perry wrote:
In message <vl0hjd$26pnn$2@dont-email.me>, at 10:38:37 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
it's usually not a skin of single bricks, but double thickness. As a
result when I've had such houses (and some older ones had even thicker >>>> walls) I've never felt that the leakage through the walls was
significant.
Oh, but it is significant.
Do the sums.
Sums need formulae, and lots of assumptions.
Of course - it's a pretty established method:
https://wiki.diyfaq.org.uk/index.php?title=Heat_loss
I am of the opinion that
the thermal inertia of a solid wall compensates for most of the lack of
a layer of insulation.
You might want to revise that opinion! Just 50mm of PIR can make a huge >difference.
I lined a north facing bathroom wall with it,
and it went from the
coldest to the warmest room in the house.
In article <vl6pc5$3fpnl$2@dont-email.me>,
The Natural Philosopher <tnp@invalid.invalid> wrote:
On 02/01/2025 15:46, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
No cavity= single brick
and double brick - as this house was built
On 02/01/2025 15:43, Roland Perry wrote:
Huh? Why are you ignoring that. One answer is not to still have "big
fireplaces", and either block them off or use wood (multifuel) burner
design.
Removing them completely is a massive exercise even if it can
be done by DIY, so the only alternative would be to completely
box them in with insulated PB.
On 02/01/2025 19:34, Andrew wrote:
On 02/01/2025 15:43, Roland Perry wrote:
Huh? Why are you ignoring that. One answer is not to still have "big
fireplaces", and either block them off or use wood (multifuel) burner
design.
Removing them completely is a massive exercise even if it can
be done by DIY, so the only alternative would be to completely
box them in with insulated PB.
It is a messy exercise, but not massive and I have DIY for 2.
That is with the chimneys in the centre of the gable end, by the ridge, chimney breasts/fireplaces 4-8 feet from the ridge, so as to be central
in the room; internal chimneys sloping over. Range size fireplace
downstairs, smaller fireplace upstairs, so the outer walls of the
fireplaces and bricks above the fireplaces were not supporting anything.
Back wall for the fireplace was 9 inch wide, no cavity, the rest of
the walls do have a cavity, so room for insulated plasterboard
afterwards. The lath and plaster ceilings were bowed and cracked already.
On 02/01/2025 19:29, The Natural Philosopher wrote:That was in the 1980s
On 02/01/2025 18:02, RJH wrote:
You might want to revise that opinion! Just 50mm of PIR can make a hugeEven 3mm of cork was enough to strop condensation on kitchen and
difference. I lined a north facing bathroom wall with it, and it went
from the
coldest to the warmest room in the house.
bathroom exterior walls...
When did you last buy cork wall and/or floor tiles, the 1970's ?.
That stuff is now quite pricey and doesn't seem to be so easily
available (as it was 50 years ago).
On 02/01/2025 15:43, Roland Perry wrote:
Andrew <Andrew97d@btinternet.com> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
As a result when I've had such houses (and some older ones had even
thicker walls) I've never felt that the leakage through the walls
was significant.
Ice box, especially if there is a gable end that is exposed to
significant wind chill too.
If and if. Possibly also "If the loft isn't insulated" too.
You really have not got a clue have you?
Loft insulation has no effect on the heat loss through a wall.
Double skin brick walls, with no insulation have a U value of around
2.1, adding a free air cavity brings that down to around 1.4.
Modern building regs require a wall U value of 0.16 or less for new builds.
A quick calculation of one end wall, 5 metres by 8 metres, a typical
house size:
Double brick, no cavity, U value 2.1 - 2016 watts heat loss through that wall.
Double brick, 50mm cavity, U value 1.4 - 1344 watts
Modern wall with insulation, U value 0.16 - 153 watts.
So your house with a double brick wall will need between 8 and 13 times
more energy to heat it to the same temperature. And now please try to
justify your comment that leakage through the walls isnt significant.
It is clearly a significant heat loss through that wall, but you have
never noticed, as you dont know any better.
On 1/2/25 19:45, Alan Lee wrote:
On 02/01/2025 15:43, Roland Perry wrote:
; Andrew <Andrew97d@btinternet.com> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
As a result when I've had such houses (and some older ones had even
thicker walls) I've never felt that the leakage through the walls
was significant.
Ice box, especially if there is a gable end that is exposed to
significant wind chill too.
If and if. Possibly also "If the loft isn't insulated" too.
You really have not got a clue have you?
Loft insulation has no effect on the heat loss through a wall.
Double skin brick walls, with no insulation have a U value of around
2.1, adding a free air cavity brings that down to around 1.4.
Modern building regs require a wall U value of 0.16 or less for new
builds.
A quick calculation of one end wall, 5 metres by 8 metres, a typical
house size:
Double brick, no cavity, U value 2.1 - 2016 watts heat loss through
that wall.
Double brick, 50mm cavity, U value 1.4 - 1344 watts
Modern wall with insulation, U value 0.16 - 153 watts.
So your house with a double brick wall will need between 8 and 13
times more energy to heat it to the same temperature. And now please
try to justify your comment that leakage through the walls isnt
significant.
It is clearly a significant heat loss through that wall, but you have
never noticed, as you dont know any better.
I don't understand this. Surely power loss through a wall is determined
by the temperature differential, as well as the thermal conductivity. So
you can't say "to the same temperature". Perhaps Roland is happier in a cooler house, or only warms specific rooms.
Also Roland makes the point about thermal mass. Averaging summer
temperatures between too hot in the day, and too cold at night will save energy/ make the house more comfortable.
It is only very recently that heating prices have been significant, I
suspect in the past it wasn't something Roland had to think too much about.
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK
house has 4.5" single skin external walls.
Probably not unusual in small, old, extensions.
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter
if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK house has >4.5" single skin external walls.
On 02/01/2025 15:46, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31
Dec 2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need >>>around 25-50W /sq meter for an English winter, and up to 200W/sq
meter if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
No cavity= single brick
On 1/2/25 19:45, Alan Lee wrote:
On 02/01/2025 15:43, Roland Perry wrote:
Andrew <Andrew97d@btinternet.com> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
As a result when I've had such houses (and some older ones had even
thicker walls) I've never felt that the leakage through the walls
was significant.
Ice box, especially if there is a gable end that is exposed to
significant wind chill too.
If and if. Possibly also "If the loft isn't insulated" too.
You really have not got a clue have you?
Loft insulation has no effect on the heat loss through a wall.
Double skin brick walls, with no insulation have a U value of around
2.1, adding a free air cavity brings that down to around 1.4.
Modern building regs require a wall U value of 0.16 or less for new builds.
A quick calculation of one end wall, 5 metres by 8 metres, a typical
house size:
Double brick, no cavity, U value 2.1 - 2016 watts heat loss through that wall.
Double brick, 50mm cavity, U value 1.4 - 1344 watts
Modern wall with insulation, U value 0.16 - 153 watts.
So your house with a double brick wall will need between 8 and 13 times more energy to heat it to the same temperature. And now please try to justify your comment that leakage through the walls isnt significant.
It is clearly a significant heat loss through that wall, but you have
never noticed, as you dont know any better.
I don't understand this. Surely power loss through a wall is determined
by the temperature differential, as well as the thermal conductivity. So
you can't say "to the same temperature". Perhaps Roland is happier in a cooler house, or only warms specific rooms.
Also Roland makes the point about thermal mass. Averaging summer
temperatures between too hot in the day, and too cold at night will save energy/ make the house more comfortable.
It is only very recently that heating prices have been significant, I
suspect in the past it wasn't something Roland had to think too much about.
In message <vl6khg$3eugf$1@dont-email.me>, at 18:05:36 on Thu, 2 Jan
2025, RJH <patchmoney@gmx.com> remarked:
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK
house has
4.5" single skin external walls.
I'm sure I've seen a few rooms like that - often garage conversions.
Then there's double-skin with the outer one brick and the inner breeze
block, which don't seem to feature much in the tables of insulation value.
On 02/01/2025 15:43, Roland Perry wrote:
In message <vl1be7$29akv$2@dont-email.me>, at 17:59:34 on Tue, 31 Dec >>2024, Andrew <Andrew97d@btinternet.com> remarked:
On 31/12/2024 06:29, Roland Perry wrote:If and if. Possibly also "If the loft isn't insulated" too.
In message <14s*uDl3z@news.chiark.greenend.org.uk>, at 17:50:09 on >>>>Mon, 30 Dec 2024, Theo <theom+news@chiark.greenend.org.uk> remarked:
I think a big unknown is the pre-WWI houses - single skin brick, >>>>>suspended wooden floors, designed to be heated with a big coal
fire running constantly. Some decent internal wall insulation >>>>>would likely help a lot there, but it's quite disruptive.
Go steady with the "single skin brick", it's usually not a skin of >>>>single bricks, but double thickness. As a result when I've had such >>>>houses (and some older ones had even thicker walls) I've never felt
that the leakage through the walls was significant.
Ice box, especially if there is a gable end that is exposed to
significant wind chill too.
Then those huge fire places andHuh? Why are you ignoring that. One answer is not to still have "big >>fireplaces", and either block them off or use wood (multifuel) burner >>design.
chimneys act like massive reverse radiators, sucking heat out
of the 'thermal envelope' and emitting it out through the
exposed chimney up above the roof line while the internal
flue stacks conduct heat out of the heated space into the
(uninsulated) section of the wall.
Barely an inch of PIR internal insulation would reduce the
heat loss to that of a 1970's cavity that had been insulated with
rockwool, ignoring the massive heatloss caused by fireplaces
and chimneys.
Blocking them off does nothing to reduce the conduction of heat
from inside the room into the solid wall and out into the
outside air.
They are gigantic cold radiators both laterally
through the gable end, and vertically into the loft and also
up and out through the physical structure of the above-roof
chimney stack. This is in addition to any passage of warm
internal air up through the chimney.
A wood burner probably requires a lining anyway with granular
insulating material filling the void between the lining and
the original chimney which would not alter the effect of
conduction of internal heat into, through and out to the
outside via the structure of the chimney.
Removing them completely is a massive exercise even if it can
be done by DIY, so the only alternative would be to completely
box them in with insulated PB.
In article <vl6pc5$3fpnl$2@dont-email.me>,
The Natural Philosopher <tnp@invalid.invalid> wrote:
On 02/01/2025 15:46, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
No cavity= single brick
and double brick - as this house was built
Then there's double-skin with the outer one brick and the inner breeze
block, which don't seem to feature much in the tables of insulation
value.
Roland Perry <roland@perry.co.uk> wrote:
Then there's double-skin with the outer one brick and the inner breeze
block, which don't seem to feature much in the tables of insulation
value.
That describes the almost every cavity wall since about 1965. I expect that's where you'll find them in the tables.
Theo
In message <vl6pc5$3fpnl$2@dont-email.me>, at 19:28:05 on Thu, 2 Jan
2025, The Natural Philosopher <tnp@invalid.invalid> remarked:
On 02/01/2025 15:46, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31
Dec 2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq
meter if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
No cavity= single brick
My solid walls have no cavity but are 9" or 10" thick (plus an inch of plaster of course.)
The model in the past was you'd just burn a coal fire all day long (later electric or gas), and it didn't matter too much about the energy efficiency of the house because you parked yourself in front of the fire. When you start thermostatically regulating the temperature then you start to notice the thermal losses.
Also Roland makes the point about thermal mass. Averaging summer
temperatures between too hot in the day, and too cold at night will save
energy/ make the house more comfortable.
It will smooth out daily peaks and troughs - this is important in summer especially (sun beating down at midday v middle of the night). But in the winter it's often cold for long periods (days/weeks), so any effect of the thermal mass is long gone (most decrement delays are on the order of hours).
Roland Perry <roland@perry.co.uk> wrote:
Then there's double-skin with the outer one brick and the inner breeze
block, which don't seem to feature much in the tables of insulation
value.
That describes the almost every cavity wall since about 1965. I expect that's where you'll find them in the tables.
On 02/01/2025 15:43, Roland Perry wrote:
Andrew <Andrew97d@btinternet.com> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
As a result when I've had such houses (and some older ones had even >>>>thicker walls) I've never felt that the leakage through the walls
was significant.
Ice box, especially if there is a gable end that is exposed to
significant wind chill too.
If and if. Possibly also "If the loft isn't insulated" too.
You really have not got a clue have you?
Loft insulation has no effect on the heat loss through a wall.
Double skin brick walls, with no insulation have a U value of around
2.1, adding a free air cavity brings that down to around 1.4.
Modern building regs require a wall U value of 0.16 or less for new builds.
A quick calculation of one end wall, 5 metres by 8 metres, a typical
house size:
Double brick, no cavity, U value 2.1 - 2016 watts heat loss through
that wall.
Double brick, 50mm cavity, U value 1.4 - 1344 watts
Modern wall with insulation, U value 0.16 - 153 watts.
So your house with a double brick wall will need between 8 and 13 times
more energy to heat it to the same temperature. And now please try to
justify your comment that leakage through the walls isnt significant.
It is clearly a significant heat loss through that wall, but you have
never noticed, as you dont know any better.
Large thermal mass means that you have to run heating continously as
the house will take hours to warm up if toy just have the heating on .
when you get home from work etc
Then there's double-skin with the outer one brick and the inner breeze
block, which don't seem to feature much in the tables of insulation
value.
That describes the almost every cavity wall since about 1965. I expect
that's where you'll find them in the tables.
Is it possible that in Roland's case there is no actual cavity?
Perhaps Roland is happier in a cooler house, or only warms specific
rooms.
No. Roland is just an arsehole.
Your calculation above suggests total heat loss of 8.5x 2016/(5x8) =
425w, which my wood burner copes with very adequately, thanks.
In message <vl6kch$3etii$1@dont-email.me>, at 18:02:57 on Thu, 2 Jan
2025, RJH <patchmoney@gmx.com> remarked:
On 2 Jan 2025 at 15:40:26 GMT, Roland Perry wrote:
In message <vl0hjd$26pnn$2@dont-email.me>, at 10:38:37 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
it's usually not a skin of single bricks, but double thickness. As a >>>>> result when I've had such houses (and some older ones had even thicker >>>>> walls) I've never felt that the leakage through the walls was
significant.
Oh, but it is significant.
Do the sums.
Sums need formulae, and lots of assumptions.
Of course - it's a pretty established method:
https://wiki.diyfaq.org.uk/index.php?title=Heat_loss
I'll have a play with that later.
I am of the opinion that
the thermal inertia of a solid wall compensates for most of the lack of
a layer of insulation.
You might want to revise that opinion! Just 50mm of PIR can make a huge
difference.
5cm - that's huge.
I lined a north facing bathroom wall with it,
And then tiled over it?
What about other rooms - a plasterboard layer
too? If you want to hang cabinets, rads etc, I suppose you need really
long bolts through to the wall behind.
How does one cope with window ledges, skirting boards, electrical
sockets... central heating pipes I suppose need a double-angle adapter.
On 02/01/2025 18:05, RJH wrote:
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK house has >> 4.5" single skin external walls.
I've lived in three that did
In message <vl6khg$3eugf$1@dont-email.me>, at 18:05:36 on Thu, 2 Jan
2025, RJH <patchmoney@gmx.com> remarked:
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need
around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK house has >> 4.5" single skin external walls.
I'm sure I've seen a few rooms like that - often garage conversions.
Then there's double-skin with the outer one brick and the inner breeze
block, which don't seem to feature much in the tables of insulation
value.
On 2 Jan 2025 at 19:28:36 GMT, The Natural Philosopher wrote:
On 02/01/2025 18:05, RJH wrote:
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec >>>> 2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need >>>>> around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK house has >>> 4.5" single skin external walls.
I've lived in three that did
Well, live and learn.
I'd be interested, if you have the time/inclination, to see any examples on Rightmove, street view etc.
On 03/01/2025 16:00, RJH wrote:
On 2 Jan 2025 at 19:28:36 GMT, The Natural Philosopher wrote:
On 02/01/2025 18:05, RJH wrote:
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec >>>>> 2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need >>>>>> around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK house has
4.5" single skin external walls.
I've lived in three that did
Well, live and learn.
I'd be interested, if you have the time/inclination, to see any examples on >> Rightmove, street view etc.
https://www.google.co.uk/maps/@52.2827805,0.2140835,3a,75y,96.25h,75.13t/data=!3m7!1e1!3m5!1sZwNKBCPMKHPhM0fa_BcF2w!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D14.865931915613402%26panoid%3DZwNKBCPMKHPhM0fa_BcF2w%26yaw%3D96.25213706096844!7i13312!8i6656?entry=ttu&g_ep=EgoyMDI0MTIxMS4wIKXMDSoASAFQAw%3D%3D
At least the porch and rear extension are single 4.5" brick and I am7213018781475853%26panoid%3DC6vN2Kdli_JQDpjcemGaxA%26yaw%3D79.97823316732611!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI0MTIxMS4wIKXMDSoASAFQAw%3D%3D
fairly sure that the main house was too.
https://www.google.co.uk/maps/@52.1986602,0.1458007,3a,75y,79.98h,87.28t/data=!3m7!1e1!3m5!1sC6vN2Kdli_JQDpjcemGaxA!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D2.
Catharine Street Cambridge. Outside walls 4.5" brick as discovered when drilling into one and the brick fell out. It wasn't even a whole prick.
https://www.google.co.uk/maps/@51.5467208,-0.1646949,3a,75y,119.66h,105.83t/data=!3m7!1e1!3m5!1sMXxpTEzxinYJVUyvRbz_tQ!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-15.826122642135488%26panoid%3DMXxpTEzxinYJVUyvRbz_tQ%26yaw%3D119.66173668119905!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI0MTIxMS4wIKXMDSoASAFQAw%3D%3D
Where it says Art College was Andy Dawson's Rally Garage. I lived in
the top flat. we know it was single brick because it had an open
fireplace and not only did we get the whole wall glowing red hot, as
seen from *outside* we poked a poker through the mortar!
On 3 Jan 2025 at 16:34:12 GMT, The Natural Philosopher wrote:865931915613402%26panoid%3DZwNKBCPMKHPhM0fa_BcF2w%26yaw%3D96.25213706096844!7i13312!8i6656?entry=ttu&g_ep=EgoyMDI0MTIxMS4wIKXMDSoASAFQAw%3D%3D
On 03/01/2025 16:00, RJH wrote:
On 2 Jan 2025 at 19:28:36 GMT, The Natural Philosopher wrote:
On 02/01/2025 18:05, RJH wrote:
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec >>>>>> 2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need >>>>>>> around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>>>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK house has
4.5" single skin external walls.
I've lived in three that did
Well, live and learn.
I'd be interested, if you have the time/inclination, to see any examples on >>> Rightmove, street view etc.
Thanks!
https://www.google.co.uk/maps/@52.2827805,0.2140835,3a,75y,96.25h,75.13t/data=!3m7!1e1!3m5!1sZwNKBCPMKHPhM0fa_BcF2w!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D14.
7213018781475853%26panoid%3DC6vN2Kdli_JQDpjcemGaxA%26yaw%3D79.97823316732611!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI0MTIxMS4wIKXMDSoASAFQAw%3D%3D
At least the porch and rear extension are single 4.5" brick and I am
fairly sure that the main house was too.
https://www.google.co.uk/maps/@52.1986602,0.1458007,3a,75y,79.98h,87.28t/data=!3m7!1e1!3m5!1sC6vN2Kdli_JQDpjcemGaxA!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D2.
Catharine Street Cambridge. Outside walls 4.5" brick as discovered when
drilling into one and the brick fell out. It wasn't even a whole prick.
What I don't understand on that street is why there's so many half bricks. I always thought regularly spaced headers were a sure indication of a 9" solid brick wall. The bond can be seen clearly at ground level - looks like a classic 9" solid type to me?!
An occasional half brick on a 4.5" wall certainly, for spacing around openings. But why so many, between the openings?
15.826122642135488%26panoid%3DMXxpTEzxinYJVUyvRbz_tQ%26yaw%3D119.66173668119905!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI0MTIxMS4wIKXMDSoASAFQAw%3D%3D
https://www.google.co.uk/maps/@51.5467208,-0.1646949,3a,75y,119.66h,105.83t/data=!3m7!1e1!3m5!1sMXxpTEzxinYJVUyvRbz_tQ!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-
Where it says Art College was Andy Dawson's Rally Garage. I lived in
the top flat. we know it was single brick because it had an open
fireplace and not only did we get the whole wall glowing red hot, as
seen from *outside* we poked a poker through the mortar!
Looks very ropey. Bit like my old east London terrace, very soft bricks. But again whole rows of headers - a classic 9" solid wall bond, I thought. I don't
doubt your expereince. I just don't understand why they built them that way, instead of using a stretcher bond (almost) throughout.
On 28/12/2024 12:33, The Natural Philosopher wrote:
On 28/12/2024 12:26, Max Demian wrote:
On 28/12/2024 11:36, The Natural Philosopher wrote:Nuclear electricity will render heat pumps both cost effective first and
I spent Christmas with a friend who has an eco house. The full 9
yards. Heat pump triple glazed, UFH with every room a computer
controlled UFH zone with its own smart thermostat, solar panels and a
batter, and heat recovery ventilation. And smart meters. Some of it
is great, some of it not so much.
What is great is the level of insulation, the UFH and the heat
recovery. HEPA filtered air is good for me, as is a totally even 19
degrees or so. There is no doubt that on a new build this is the way
to go, although the active ventilation requires constant servicing to
clean the filtration.And it can get stuffy.
What isn't so great is the heat pump. It works just fine. But it
costs him more than the gas in his old Victorian property used to,
due to the exorbitant price of 'renewable' electricity.
I think they'd have to repeal the second law of thermodynamics to fix
that, unless they get all the people with gas boilers to subsidise the
heat pump users - and cope with all the millions of people freezing to
death as they can't afford to heat their homes.
then irrelevant, as electricity will be so cheap that spending money on
using less simply wont be worth it...
Err, that's what they said 70 years ago, and we are still waiting.
All we should be interested in here is the difference between a hundred
year old house with a solid brick wall, and a hypothetical hundred year
old house with a cavity wall.
On 03/01/2025 12:25, Roland Perry wrote:
Your calculation above suggests total heat loss of 8.5x 2016/(5x8) =
425w, which my wood burner copes with very adequately, thanks.
No, you still dont get it. That is the heat loss through one wall. Then
you have the ventilation losses,and the floor and ceiling losses.
For your wall,at 4m x 2.5m
with a cavity brick wall, at a U value of roughly 1.4, will have a heat
loss of around 285 watts, add in the window at a u value of 2 adds
around 72 watts,
so roughly 350 watts heat loss through that one wall.
Ventilation losses will be anything above 500 watts, probably nearer
1000 watts, presumably the ceiling is to a bedroom, so that is
disregared, assuming the bedroom and all adjacent rooms are heated to
the same temperature (if not the heat loss will be higher), so we have
heat loss through the floor, which with a 6x4m footprint, loses around
600 watts of heat.
So a conservative figure of heat loss for that one room will be around
1500 watts if the house is reasonably well sealed, and all rooms in the
house are to the same temperature.
If its even slightly draughty, the heat loss will be well over
2000watts, which I would assume is the case, as to work, the wood
burner needs a fresh supply of air, using the design guide figures
would give a heat loss for that room at around 2800 watts.
These figures assume a standard -3 outside and 21 inside temperatures.
A modern house to current building regs will be around 630 watts.
So the window is more lossy than my solid brick wall?Last time I did the calcs the walls with greater area represented more
On 2 Jan 2025 at 20:18:54 GMT, Roland Perry wrote:
In message <vl6kch$3etii$1@dont-email.me>, at 18:02:57 on Thu, 2 Jan
2025, RJH <patchmoney@gmx.com> remarked:
On 2 Jan 2025 at 15:40:26 GMT, Roland Perry wrote:
In message <vl0hjd$26pnn$2@dont-email.me>, at 10:38:37 on Tue, 31 Dec
2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
On 31/12/2024 06:29, Roland Perry wrote:
it's usually not a skin of single bricks, but double thickness. As a >>>>>> result when I've had such houses (and some older ones had even thicker >>>>>> walls) I've never felt that the leakage through the walls was
significant.
Oh, but it is significant.
Do the sums.
Sums need formulae, and lots of assumptions.
Of course - it's a pretty established method:
https://wiki.diyfaq.org.uk/index.php?title=Heat_loss
I'll have a play with that later.
It's worth it - if you're OK with spreadsheets. I see you've had a go at >calculating heat loss further down this thread - I'd guess you're >underestimating heat loss by a factor of about 3 using whatever method you've >used.
It takes a while to set up, and took me an hour or so to do my home. The good >thing is you can tweak the variables to suit your circumstances. For example, >I very rarely heat a room to 21C - it's simply too warm for me. But putting in >standard variables helps with design, estimating improvements, and >highlighting problems.
I am of the opinion that
the thermal inertia of a solid wall compensates for most of the lack of >>>> a layer of insulation.
You might want to revise that opinion! Just 50mm of PIR can make a huge
difference.
5cm - that's huge.
I don't think so - 2"?! But if your rooms are quite small, yes, it can be a >problem. If you put the PIR in alcoves you'd barely notice. Also, if you go >back to brick, you'd likely find the space loss barely noticeable.
I lined a north facing bathroom wall with it,
And then tiled over it?
Yes. Over WP plasterboard.
What about other rooms - a plasterboard layerYes, plasterboard layer. And with it some pain if needing to wall mount >anything heavy. But there are loads of workarounds.
too? If you want to hang cabinets, rads etc, I suppose you need really
long bolts through to the wall behind.
How does one cope with window ledges, skirting boards, electrical
sockets... central heating pipes I suppose need a double-angle adapter.
With reveals I've had to cut down the insulation to 25mm. And again plenty of >workarounds for wiring and plumbing. The biggest issue I have had is with >elaborate skirting boards that need to be retained. That can be a pain.
On 3 Jan 2025 at 11:56:05 GMT, Roland Perry wrote:
In message <vl6khg$3eugf$1@dont-email.me>, at 18:05:36 on Thu, 2 Jan
2025, RJH <patchmoney@gmx.com> remarked:
On 2 Jan 2025 at 15:46:01 GMT, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec >>>> 2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need >>>>> around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
I'd use the term solid brick - so a 9" wall. I don't think any UK house has >>> 4.5" single skin external walls.
I'm sure I've seen a few rooms like that - often garage conversions.
Yes - outbuilding maybe. But not part of the main house IME.
Then there's double-skin with the outer one brick and the inner breeze
block, which don't seem to feature much in the tables of insulation
value.
They'd be available if you know what it's made of. This is the most >comprehensive database I've found:
https://www.ubakus.de/en/r-value-calculator/index.php?
But it's always going to be difficult to know exactly. The bricks my current >home is built of must be over twice the weight of a modern brick - so, I would >assume, they have different thermal characteristics.
One additional problem I have is working out the temperatures within these >sandwiched materials - where the brick ends and the insulation starts, say. So >I just guess.
On 04/01/2025 10:27, Roland Perry wrote:
So the window is more lossy than my solid brick wall?Last time I did the calcs the walls with greater area represented more
loss than a single glazed window in most cases.
In fact installing DG is probably the least effective way to reduce
heatlosss except that it usually is draught proof.
With reveals I've had to cut down the insulation to 25mm. And again plenty of workarounds for wiring and plumbing. The biggest issue I have had is with elaborate skirting boards that need to be retained. That can be a pain.
On 02/01/2025 20:00, charles wrote:
In article <vl6pc5$3fpnl$2@dont-email.me>,
The Natural Philosopher <tnp@invalid.invalid> wrote:
On 02/01/2025 15:46, Roland Perry wrote:
In message <vl0l2h$26pnn$11@dont-email.me>, at 11:37:53 on Tue, 31 Dec >>>> 2024, The Natural Philosopher <tnp@invalid.invalid> remarked:
However for normal-ish houses you are probably looking like you need >>>>> around 25-50W /sq meter for an English winter, and up to 200W/sq meter >>>>> if its single brick.
Again, is that a single brick, or a 10" double-thickness wall?
No cavity= single brick
and double brick - as this house was built
Or shuttered concrete as my grandparents house was constructed
so in Epsom. (17 Worple Road)
The ground and first floor were built like this. Grandpa used
to amuse himself getting quotes from tradesmen to open up a
new internal doorway between the back kitchen and the back
room so that it could be used as a ground floor bedroom.
Quotes were always based on the assumption that being an
internal wall it must be single skin brick or similar, while
he knew it was 6 inch *really* tough concrete.
This was pre 1960, so none of those fancy power tools.
Rawplugs were inserted into holes made with a device that
had to be hit many many times with a club hammer while
turning it in the hole. Unbelievable tough walls.
Even in 1993 when Grandma died, she was paying over 1000
a year gas bills to heat the place. Turn the heating off
for only a few days and it took over a week to get the
house back up to a liveable temperature.
I've lived in three that did
Well, live and learn.
I'd be interested, if you have the time/inclination, to see any examples on >> Rightmove, street view etc.
https://www.google.co.uk/maps/@52.2827805,0.2140835,3a,75y,96.25h,75.13t/data=!3
m7!1e1!3m5!1sZwNKBCPMKHPhM0fa_BcF2w!2e0!6shttps:%2F%2Fstreetviewpixels- >pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3
D600%26pitch%3D14.865931915613402%26panoid%3DZwNKBCPMKHPhM0fa_BcF2w%26yaw%3D96.2
5213706096844!7i13312!8i6656?entry=ttu&g_ep=EgoyMDI0MTIxMS4wIKXMDSoASAFQAw%3D%3D
At least the porch and rear extension are single 4.5" brick and I am
fairly sure that the main house was too.
https://www.google.co.uk/maps/@52.1986602,0.1458007,3a,75y,79.98h,87.28t/data=!3
m7!1e1!3m5!1sC6vN2Kdli_JQDpjcemGaxA!2e0!6shttps:%2F%2Fstreetviewpixels- >pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3
D600%26pitch%3D2.7213018781475853%26panoid%3DC6vN2Kdli_JQDpjcemGaxA%26yaw%3D79.9
7823316732611!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI0MTIxMS4wIKXMDSoASAFQAw%3D%3D
Catharine Street Cambridge. Outside walls 4.5" brick as discovered when >drilling into one and the brick fell out. It wasn't even a whole prick.
Catharine Street Cambridge. Outside walls 4.5" brick as discovered when
drilling into one and the brick fell out. It wasn't even a whole prick.
Yep back in 78 was looking to buy a house there but patriarchal building society manager said No!, its got a 4.5 inch single end wall you can do better and we did.
Those streets are going be a real PITA for EV charging mind you in
Cambridge the local council would prefer you to walk or use your push
bike and abandon the car!..
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