Insulation Works - Shall I knock down my house?

[JP_]

Today I moved my desk back into the lounge, which is the south facing new extension. The rest of the house is 1930s bungalow, and north facing. I did this because I am home alone during the day and realised, now it is colder, that the lounge stays warm all day without the heating on, while the front cools down.

Heating goes off at about 8am, and by 1pm the front of the house is down to about 16 degrees, while the lounge is still 21 degrees. Now, you might be thinking - is the old front not insulated? Yes! I have insulated the floors and walls with 50mm kingspan, and there's heaps in the loft. There are no drafts and it has good windows. But that is still no match of a south facing modern construction with 10cm rockwall plus inner leaf of thermalite blocks.

Of course, this is not really a problem at all, as its only bedrooms at the front which are nice and cool. But, it goes to show, if you want a warm house without heating, you need very good insulation and facing the sun (even if cloudy).

I won't be rebuilding the front of the house, but as the pebbledash is falling off all over now, I do need to render it all, and wondering now if boarding with insulation render board would actually be easier than scraping all the pebbledash off ...

 

[RandomGrinch]

Currently, with the widespread reporting of Cop26, climate change, heat pumps and gas boiler bans etc., I have been wondering where the balance lies between, say improving the energy efficiency of old buildings, or just knocking them down and starting again!

I may be wrong, but I suspect demolishing and rebuilding row upon row of Victorian terraces (around where I live), would cost so much CO2 in construction material production and transport, that it would be completely untenable!
And that's not saying anything about cost.

Even given the vastly greater energy efficiency of new-builds, will they still be standing in 130 years time?

I suspect retrofitting efficiency improvements is the only economic way to go.

I really must do the sums!

 

[motorbiking]

If you’ve already added 50mm celotex then external insulation will only take it from A U value of around 0.4 to 0.2.

I suspect you are experiencing some solar gain

 

[johnny2007]

No matter what you do, the south facing part of the house will always be warmer and stay so for a lot longer than the north side.
I installed a larger radiator in the front bedroom facing north for this exact reason.

 

[JP_]

yeah the front rooms have large rads. Today is actually feeling colder in the lounge, very overcast out there. Still says 20 degrees, but feels chillier.
Maybe I should just move to Spain.

 

[wobs]

Currently, with the widespread reporting of Cop26, climate change, heat pumps and gas boiler bans etc., I have been wondering where the balance lies between, say improving the energy efficiency of old buildings, or just knocking them down and starting again!

I may be wrong, but I suspect demolishing and rebuilding row upon row of Victorian terraces (around where I live), would cost so much CO2 in construction material production and transport, that it would be completely untenable!
And that's not saying anything about cost.

Even given the vastly greater energy efficiency of new-builds, will they still be standing in 130 years time?

I suspect retrofitting efficiency improvements is the only economic way to go.

I really must do the sums!

Don't knock down your house, its better to retrofit, as there is less concrete/steel produced by doing so.

While we can't on ours Edwardian house, it would be better to fit external insulation on a solid wall construction, and use the brick work internally as a heat store.

And of course, you can always use a blanket. We have at least one on the sofa all of the time.

But from a climate change perspective, it cannot solve the issue without some control on the economy, as efficiency measures can increase carbon emissions in the long run. We need to move away from fossil fuels (why there is a puch for heat pumps, despite their obvious flaws), and where we can't, have some way of limiting it's consumption without impacting on the vulnerable. So injecting hydrogen into the network, biogas are options in the foreeable future, but not tortal solutions.

 

[JP_]

Developers bought the 1930s bungalows next to me, and pretty much knocked them down. They kept the external solid brick walls, but removed everything else - rear wall (for extension), floor, roof, internal solid walls (to redesign layout) and put in lots of insulation. Must be far more effective than retrofitting around existing - the whole floor was covered in insulation then screeded, with underfloor heating laid.

Probably the best solution really.

I feel cold today. Really making an effort not to turn that heating on though! Not so much to save the planet, but to save my bank balance from falling into the red ...

 

[RandomGrinch]

Developers bought the 1930s bungalows next to me, and pretty much knocked them down. They kept the external solid brick walls, but removed everything else - rear wall (for extension), floor, roof, internal solid walls (to redesign layout) and put in lots of insulation. Must be far more effective than retrofitting around existing - the whole floor was covered in insulation then screeded, with underfloor heating laid.

Probably the best solution really.

That maybe a good compromise. It was obviously worth it from an economic point of view.
But I wonder how much it cost in CO2 and how long it would take for the efficiency improvements to payback, and for the development to become net carbon neutral.

... And as @wobs says, as our energy production becomes less carbonised, so the efficiency of a house may not matter as much!

There is a well known phenomenon with lighting; the more efficient it gets, the more lights we want!

 

[JP_]

While we can't on ours Edwardian house, it would be better to fit external insulation on a solid wall construction, and use the brick work internally as a heat store.

Yeah, I didn't do this for various reason though:

• Internally insulating is cheaper, and easier for DIY
• I didn't have the money to do it all at once, so been renovating rooms as I go (4 years now!)
• The rooms needed renovating anyway - floors needed insulating, new radiators, electrics, skirting removed (very old, some rotten etc) new ceiling (overboarded) all skimmed - so disruption going to happen anyway
• Lots of cables on external walls - gas pipes, telephone cables, TV cables, electric cables ...
• Was doing an extension first, and didn't want finished walls to be stepped in, or out, after adding external insulation

But saying all that, I am seriously considering some external insulation, just to beef it up a bit. I am sure it will help. But cost might still be too high. I wouldn't put in 10cm though as that would mean all windowsills needed changing, and soffits and facias probably need extending, so too much work. But a thin insulated render board might be a solution ...

 

[JP_]

Another thing ...

https://www.tesla.com/en_gb/solarroof

I have a big roof, being in a long bungalow, almost the size of a tennis court. It might actually make sense ...

 

[^woody^]

Surely if the back is 21° and the front 16°, if you open the room doors, the whole bungalow will be 19° and bearable?

 

[JP_]

Nah, all the heat will just get lost through the hallway and there'll be a constant draft.
21 is comfortable for me, so I am keeping the door closed and the heating off. By time the kids get home from school, and wife home from work, the heating is back on again til about 11.

 

[Justin Passing]

"walls with 50mm kingspan"

Beware condensation with internal insulation. You don't want the dewpoint in the wall. Did you work it out?
If your external render is falling off, then ext insulation sounds reasonable. As it's a bungalow, why not muchly a diy job? I hear you on pipes and wires. .

 

[motorbiking]

There is another option. Solar panels and reversible air conditioning.

 

[JP_]

"walls with 50mm kingspan"

Beware condensation with internal insulation. You don't want the dewpoint in the wall. Did you work it out?
If your external render is falling off, then ext insulation sounds reasonable. As it's a bungalow, why not muchly a diy job? I hear you on pipes and wires. .

No, didn't work that out, but made sure every board was well taped top to bottom, so no moisture should get through. And if some does, better the damp in the wall than in my rooms and lungs!

Yeah, I might end up boarding it myself then getting the plasterer round to render, although there is the apex at the front that is going to need a scaffold ... although that part does not need insulating as it's just the loft.