Self-build mortgage advice needed

bpk101

Hi, my OH and I have recently been looking at the prospect of a self-build project for our next, 'forever' home with a goal to complete it in 5 years time. Some rudimentary number crunching has deemed the project a real possibility but financing the land (or in our case, a run down house to demolish and replace) is highly unlikely to happen using cash savings, therefore i need to research mortgage options. Does anyone have experience with this? I'd really appreciate some advice if so. 

We're currently paying a mortgage for the house we live in now which we bought back in 2015, of which we've paid off about £60k and through extensive renovation added about £300k to the value. Earlier this year we switched our mortgage to a part capital, part interest mortgage to free up some money as we had our first child and my OH was going on maternity leave. We fixed into this mortgage for 5 years. 

Given our fixed situation, will a second mortgage to buy a house with plans to demolish and re-build be possible within the next 5 years?
If so, who are the best lenders to approach for this sort of thing? Our current mortgage is with Natwest.

Thanks.

bpk101

Anyone?