LOL please go look at a map of London, Z1-Z2. Protection? It's almost like every other building is "protected"!
Plus, read my comments. I'm saying the government should take care and sponsor the fixes to ensure the quality while greatly reducing the energy bill (that's my thesis).
London is 2000 years old. There are lots of historic buildings. There are energy saving grants available. Building regulations on insulation (including glazing) are very strict, but they're not retroactive until further work is done on the building. That's when you do see the double glazed units in sash windows. These are, incidentally, very expensive items, but then so is most listed building work. If you don't want it, don't buy a listed building.
Plus, read my comments. I'm saying the government should take care and sponsor the fixes to ensure the quality while greatly reducing the energy bill (that's my thesis).