I don't know of any banks any more that will do a construction loan on investment properties based on completed value (i.e the finished value with the built in equity).

@Marcus Auerbach, there are plenty of lenders who use a DSCR 1 ratio and base the rents on actual rents or the rents on the appraiser market rent survey.

Im based in the UK - hope that is OK.I am primarily looking for info on deal calculation and also what I need to have inplace / ways / strategies to raise investment capital. 

They are just far to speculative and all over the place with values for me to want to base a contract/option off of it.  

I would maybe even wager you are negative or break even just looking at cash flow.

I had previously read something like 48% of people travel with their pets, and I do believe it based on the amount of pet fees we collect. 

I just add that amount to the base rent in the lease. 

Many reputable general contractors have experience with city/township inspections and final inspections before you can sell your home; they can provide value based on experience with trades inspectors and providing more accurate estimates for project costs based on current market value of work per trade. 

I recommend looking into areas near economic bases - close to Nationwide Children’s Hospital, Ohio State Campus, New Albany, etc.

They can give you projections based on historical data.