Self Build mortgage HELP

[Amateur bob]

Good afteroon, i have been speaking to 2 well known mortgage brokers to lend me money to build a house on the farm, they have come back to me with the options chorely and hanley economic,

 

the only issue is that the plot is next to the farm and 30ft from a shed and the track in is 600m long and isnt tarred, theyve both told me its an 8 week process applying and at the end of this time period the valuer goes out to the site and the whole deal is subject to the valuers comments regarding how easily resaleable the plot is if it has to be reposessed

 

ive been warned that this could be a stumbling block, what are peoples thoughts? should i scrap the self build loan idea and instead apply for a business loan and secure it on some fields thefarm owns? id be looking at an extra 2,5% interest rate with this option although offseting against tax should reduce this

 

thanks