A question about IHT and my parents house.

[l04139]

I myself am Autistic but I do not have learning difficulties. My brother on the other hand has Autism with bad learning difficulties. My parents wish to not leave a will as they know that Interstate will kick in and the house will be divided by the administrator of the estate. My mum wishes for us to keep the house while my brother is alive so he will always have a roof. I am perfect with that. I have done research on this and I have another brother who might get in the way but to my understanding... If the house ownership is divided 3 ways to us 3 then all of us have to agree for selling.. So if I say no then the house will not be sold? Our house is under the IHT threshold. Mortgage will bring the value of the estate down regardless (There is over 10 years left) If by chance it did go over the IHT (Prices always change) would my brother be able to carry on living in that house if we don't have the funds to pay the Inheritance tax? I know that if there is tax then it must be paid within 6 months or it will gather interest