[danans]

> An interesting aspect of a "Green New Deal" would be to subsidize electrifying the HVAC & insulating our older buildings.

This is the great part of the Green New Deal that was shouted down when much of the political establishment mocked it - it would put scores of people to work in jobs in the trades.

[litany]

Unfortunately insulating a building after the fact is extremely difficult, expensive, and depending on climate can approach the level of near tear down. I think it many cases it may ultimately be more environmentally friendly and cost effective to add things like solar and just brute force the heating/cooling.

The reason for this is that buildings not designed for insulation and air sealing can suffer from dramatically worse durability (mold etc) when just adding insulation. It is not necessarily wise to just add fiberglass batts to wall cavities.

The addition of insulation to our homes is a modern thing, and there have been significant issues even currently (the mold crisis).

The issue is that to build a building properly, it is necessary to address heat flow, vapor flow, air flow, condensation, drying, and water barriers. This means you often have to address the entire envelope of the building, which is very expensive, difficult, and means replacing a lot of material. Basically remove all cladding and sheathing and upgrade it.

Realistically most of these concepts are not well understood in the construction industry, and the expense is high so most corners would be cut leading to huge issues with mold and wood destroying pests down the road.

[andys627]

> Basically remove all cladding and upgrade it.

This is not extremely difficult nor expensive on every building. It's certainly more of a job than cutting holes in the wall on the inside and blowing in insulation. By insulating from the exterior you can address vapor issues. There are benefits: you can avoid having to patch holes (2 per stud bay... ie a lot) and repaint the inside. There's opportunity to upgrade electrical or fix any issues. Siding also has a limited lifetime. Wood siding can be reused.

With some/many buildings it is certainly too hard and expensive, but for many this is not. We shouldn't write off the whole idea because it doesn't apply to all buildings.

[DoofusOfDeath]

Fortunately, at least in the U.S., our building codes for new and renovated buildings help ensure that, over time, most of our buildings will be well-insulated.

But, I don't know how well current codes ensure that all aspects of IAQ are reasonably safe, particularly in residences. I'd need to check, but not sure they seriously address prolonged, elevated exposure to VOCs. I fear that decades from now, we'll learn we harmed a lot of people via prolonged exposure.