Well that's full of really useful tips. I'll get the builders in to construct a 1.37m (4.5ft) thick spine through the middle of my house. Obviously.

Modern insulation is really, really good, and modern heatpumps are very energy efficient and don't pollute your house with CO, CO2, and particulate matter like woodsmoke. Also, modern double- or triple-pane windows insulate much better than drafty Elizabethan windows. We live in a time of marvels.

You're talking about the best of what's available but that is rarely what builders use and retrofitting your already constructed house to use these could end up costing you 1/3 or more of your home's original value.

All that is to say that builders cheap out on new home construction so most people don't get to enjoy the benefits if these innovations.

Not sure where you live, but all of that stuff is minimum code in new construction where I live. And it is inspected.

In the UK it's minimum code and we don't bother to inspect. We trust the building firms to self-certify, with predictable results...

Um, nobody builds a house without modern insulation (rock wool etc) and 3-pane windows. It wouldn't be legal either.

Build, no. But here in New England (Boston suburbs) even double-pane windows are still quite rare, because most houses are ~100 years old or more.

I live in Edinburgh, and 100 year old buildings are the newest ones in the city. A good chunk of the city is what we call a “conservation area” - so you can’t modify the aesthetic of the building (windows included), but the vast vast vast majority of people outside that space have double glazed windows I’d wager.

Windows have a lifetime of only 15-30 years, though. If you have to replace them anyway, you might as well get double-pane (even if the rest of the house isn't well insulated).

I think this is the stated lifetime of insulated windows. But obviously single glazed windows were never insulated in the first place so there is no practical lifetime on them...

In my house and on my road a lot of the glass is 150+ years old.

Haha. Made of what? Come on, around here there are plenty of wooden doors and windows 70-100 yo and this is a humid climate.

What does 'lifetime' mean? Mine are nearly all original.

Windows last hundreds of years because glass lasts hundreds of years.

Modern windows don't last very long, because the seals leak, and the argon gas or whatever leaks out. The glass is still good, but the insulative quality is gone.

The parent poster didn't realize that if you don't have double pane windows, you have single pane windows, which have no gas to leak.

Even if it's mostly air it insulates quite a bit better than single pane windows. Of course worse than with the original gas filling, as the windows are optimized for maximum distance between the glass panes without having the inner gas start to "circulate" - which starts to happen at a smaller distance for air than for the noble gasses.

Yes, for sure. My house is 65 years old, and all the windows have leaked.

But my point was that windows, the glass part, lasts centuries, if not longer. Not the mere decades cited upstream.

I live in the UK and nobody is replacing windows every 15 years. 30 _maybe_

That is the stated lifetime - but they typically last much longer.

That depends where you are. Here in Australia the default is single glazed windows, and double glazed is hideously expensive, especially to retrofit.

Sounds you're somewhere with some actual building standards though.

Also in australia, the BCC/NCA is an absolute joke compared to basically every other industrialized country. There’s a reason for the annual “Austrlian houses dont meet WHO minimum standards” articles.

As an example single pane windows havent been effective or widely used since the 70-80s in north america and europe. And both places energy standards effectively preclude them since 2000ish. Or insulation in australia is effectively absent in pre 2000s, and maybe R-4ish on a new build now. Conversely NA was R-4 in the 70-80s and it would be about R-6 (or more) these days.

Our residential solar and heat pump uptake is great. But for building standards and quality were a joke.

You're missing out if you don't have such thick mass of warm brick/stone. If you only knew how great it is to sleep on top of it (my grandmother had similar to that in her house :)

https://en.wikipedia.org/wiki/Russian_stove

Modern fire codes require large space between a stove and walls which is usually goes unused where it could have been really filled with such a thick brick structure with the smoke passage snaking through it like in Russian and German stoves. Or like this:

https://www.mha-net.org/wordpress/wp-content/uploads/2020/05...

Fire codes in the UK would allow a stove as close to the wall as you would like

the modern way of doing that is ICF - insulated concrete forms.

I remember talking to a builder once who was building a house this way. He said the mass wasn't allowed to be advertised with an R-value since it wasn't actually insulation, but he said it was comparable to an R-50 house.

ICF is great but it's still uncommon. Most contractors know nothing about it.

ICF homes are also VERY air tight. They often need special variable output heating and cooling.

Most high quality modern homes are built to be air tight and bring air in with exchangers. Monopoly framing is how they are approaching this with stick frame houses. They essentially create what looks like a building from the game Monopoly (no overhangs) with air tight materials and tape every hole they can find. They will install a blower door and measure how much air leaks from the building envelope. The overhanging features are installed outside of the air tight monopoly frame.

This is what a monopoly framed house looks like before the roof and siding are put on: https://www.afirsttimehomebuilder.com/img/pure_monopoly_fram...

All of the Zip boards are air and water tight and they use the tape on all of the seams to seal those. The roof will sit on top of the already water & air tight frame. Same with the siding.

It takes a LOT of effort to make stick framed homes as air tight as ICF houses automatically are.

I had trouble with my heating system and got a good long talk with the HVAC pro.

I think variable output heating/cooling has one interesting capability - it can adjust to things you've adjusted. For example, a one or two-stage heating system has trouble if you close heating vents in some rooms. It might overheat if too many are closed for example. With a variable-output system, it can support this. further with variable dampers it can support zoned heating and cooling. You can give the places that need it less or more airflow and have a more comfortable house without waste.

after seeing things like heatermeter (pid controlled smoker controller based on the raspberry pi), I wonder why this kind of convenient and efficient control isn't more common.

Passive solar houses do exactly this. But you're fundamentally right, it's not really a retrofit. It's a goal you set for the next house.