It depends on how the 3 of you own the property. If you own it as are "joint tenants" you own the whole property jointly – which is what joint tenants do - in the event of the death of one of those joint tenants, the whole property automatically passes to the surviving tenants irrespective of any will. A joint tenant is quite entitled to sever the joint tenancy unilaterally. Then you become tenants in common and can dispose of their share as they please.
If you own your home as "tenants in common", you each own a distinct share of the property & if your brother died without a will & without children that goes to his father. If you are tenants in common, the choices you have are similar to those available to a couple splitting up, or friends who have bought jointly moving on, where one person wants to stay in the joint home. You could offer to buy out your dads share or sell your share to him.
There are also two possible avenues of legal action. This not a pleasant option, however you should be aware of it in case the worst comes to the worst. Depending on whether your situation fits the required facts, you may have a case (i) under the Inheritance (Provision for Family and Dependants) Act 1975; or (ii) if you are a tenant in common, that your share is greater than one-half on account of your joint intentions to the property, as inferred from all the circumstances including your financial contributions.
Get detailed, specific, bespoke advice!