young adult / parent's property

[nightcat]

I am puzzled and need a legal eagle to explain something to me.
Where I grew up it was totally normal that when a child became adult s/he was by default a co-owner of the property s/he was living in with the parents and if the parents died s/he was neither forced to sell it nor pay any inheritance taxes, after all it was his/hers residence.
Here it seems to be different and as my ds is in late teens and disabled, I would hate for him to become homeless if something happened to us.
So, how can one make a young adult a co-owner of the house to ensure that he can stay in it (as it's beed adapted). I think he would probably be able to live alone with some help, but I would hate for him to be turned out of his own home and he definitely wouldn't be able to handle the sale, move, adaptations etc.
Does anyone have any advice?

[Collaborate]

1. Make a will
   
2. Take the advice of a trust/tax specialist to see how /if the property can go in to a trust to reduce or extinguish inheritance tax. There might be special provisions where the beneficiary is disabled, but I'm just making a wild guess here. Proper professional advice is essential.

[nightcat]

thank you Collaborate, I am gathering my thoughts how best to approach it before I go to see the experts