The £ devalues by 5.47% a year so anything below that is technically fine.We will have 500K and 29 years left to go at renewal in 2025 (with 200K of equity in the property), combined salaries of 165K.
It's surprisingly close to being unaffordable at anything over 5% mortgage rate. Though I guess our salaries will go up a bit over the next 2 years.
We could probably manage 6% - but it wouod be tight.