Probably an accumulation of a lot of tech where it's cheaper to buy new than refurbish/maintain: New roof, new wiring, new windows, new facade, updating to latest building codes.

Insulation. In the UK an older £250k house could have £2k additional heating for equivalent comfort. Over decades that adds up. If climate change makes summers hotter so cooling systems/AC need retrofitted and winters colder, that'll be more pressing.

Modular factory built homes might be possible to disassemble or extend, allowing reconfiguration that people might come to demand.

This will also be pushed by other trends, aging populations mean people might demand more housing that better suits their needs and new is cheaper than adapting.