Career pivot to BS in UK

Hello, my husband is 40 years old and a qualified social worker in the UK supporting older adults. He earns £44,000 and that’s the highest his salary will get. He’s been doing it over 10 years and considering a career change.

His only experience of building surveying is from us hiring one each time we move house to provide us with a structural survey.

Our issue is our mortgage is very high. He’s looking at doing a masters part time (like distance learning though we do live in Nottingham so could consider NTU), while continuing to work full-time as a social worker. The issue is it seems he has to then go through 2-5 years of working with a salary below £40K? Can anyone speak to this? How quick could he get back to ~£44k?

Could people also advise whether there are many opportunities for doing structural residential surveys in Nottingham/the UK and are companies open to remote working (besides you going on visits)?