Build quality in the UK is generally dire. Mortar and bricks of old buildings crumbles. Lots of asbestos. Leaky pipes cost too much to fix, electrics are old and a hazard... New buildings favour low cost over quality. Staircases crack away from walls 12 months in. Insulation is designed to meet green targets, but not to actually insulate. Compared with the standards-obsessed Germans, I suspect many buildings in the UK should really be demolished. It's but one of the reasons I'm selling up in London and moving to the mainland.

You miss out on a lot of modern advancements. A few things that come to mind from my lovely house:

* Single pane windows that leak heat / cool, also that rattle.

* Lack of insulation.

* Non-grounded wiring / unsafe wiring.

* Plaster instead of drywall, cracks very easily.

* Old heating systems (oil furnace with steam radiators).

* Crooked doorways and doors that don't close quite right.

Nothing wrong with old. Just that its related to the OP - construction costs are irrelevant when you can amortize the cost over a century or two.