Banks stress test this before giving mortgage approval. Also you won't get a mortgage rate of 0.5% anyways.
In my case, if that happens, I would probably eat out less every month..
Life then goes on.
You clearly aren't on a typical wage. The UK median household income is £31k, or lower at £27,590 if you look at 21-30 year olds alone. The majority of 21-30 year olds have a household income below £28000/year. The widely accepted 'sensible' salary:mortgage ratio is 3:1. The historical norm is 4:1. To buy a house in the majority of the UK with that income, you're looking at a 5:1 or 6:1 ratio or a very large deposit.