Borrowing Advice

hamster2013

check the post office mortgages
if you went with 75% LTV, you will get a 3.28% fixed for 5 year rate without any fee's (or 2.89% if you have the £1000 upfront for the fee's)

the difference of borrowing £1500 at 3.28% v/s 2.89% over 25years is £733 v/s £703, i.e £30/month extra, so over the fixed 5 years, that represents £1800 - therefore, if I were you, i would pay the £1000 upfront + around £300 for the valuation - saving almost £500.

As for reducing your duration of mortgage - dont' do that now - go for a 25 year mortgage fixed rate - and at the end of the fixed period, renegociate a new mortgage that would be shorter.
you will be able to secure a better loan maybe as your LTV would have been bettered - after 5 years at 2.89%, you would have repaid almost £22k, so your remaining mortgage on the house would be 'only' £128k (evenif property value stayed same, i.e £200k - you would be very close to the 60% LTV...)