If you're not planning on selling your house it's future value is irrelevant. All I care about is the purchase price of my "forever home".
The only difference it makes it that if your lender gives more favourable interest rates when your loan to value ratio improves. So if you purchase a house and the price doubles, your LTV is already 50%. Conversely if it drops after you paid off half the mortgage, your LTV might be shit
I'm not sure if the thing about LTV is true considering the whole picture, since the loan is larger. A larger loan at a lower interest rate still has large monthly payments. (I'd have to do the maths to be sure ...)
I looked up one of the major banks in my country and the difference in mortgage rates and monthly repayments for different LTV ratios is as follows for a €500k property with €50k down payment:
LTV <50%: 3.75% €2668pm
LTV >80%: 4.15% €2762pm
Over the lifetime of the loan you'll spend roughly half of the time paying the upper rate and half paying the lower rate.
However, if, over the first 10 years of the mortgage, your house halves in value due to a recession then you won't break the 50% LTV mark until year 15 (2040).
On the other hand, if house prices were to increase by 50% over that period then you might hit the 50% LTV mark within 7 years (2032).
The difference between the total mortgage interest in these two scenarios is €9216. The only thing that changed was the valuation of the home.
The only difference it makes it that if your lender gives more favourable interest rates when your loan to value ratio improves. So if you purchase a house and the price doubles, your LTV is already 50%. Conversely if it drops after you paid off half the mortgage, your LTV might be shit