Buying a new build on PX but in negative equity

Superdan2011

Hi all, hoping to clear up a confusing one...

I have never owned property but my partner owns a flat and we are looking into the possibilty of buying a new build property with a PX option.
She has 2 years left on her mortgage deal but they have agreed that i can be added to the mortgage and so increase the mortgage to fund buying the new build.

The mortgage she has is £125k interest only, but the flat is now only worth £110k which we estimate will be the px offer. New build price is £225k.
My question is, will the negative equity not matter because we arent actually remortgaging? .... or....
Will it be added to the increase in value of the revised mortgage?

I hope the question makes sense, thanks for any help on this

Dan

liubeliu

You will need to have extra monies to cover the neg equity and the deposit on new build.

Lets assume 75% LTV mortgage and px of £110,000 you will need £56,250 deposit and £15,000 to clear neg equity so £66,250 in total and mortgage of £168,750

Plus all other fees and costs. Also PX likely to be lot less than market value