Can you stipulate a percentage share of ownership between two people on a house title deed? Say one person has 70% share, the other 30%... is that possible? Or can this be arranged separately through solicitors?

I don't know if you are in the US as you've referred to attorneys by "solicitors", but here in the US the way I would do it is to have an attorney prepare a trust.

This is a lot simpler than it may sound. A trustee will be appointed (like a bank) who holds title to the property and follows the beneficiaries' (owners) instructions which are laid out in the trust agreement. The trust agreement will have an Exhibit called "Beneficial Interest". There you can name one party 70% beneficial interest and another 30% beneficial interest, and state that current or future proceeds are to be split according to each person's beneficial interest.

I bet there is an equivalent for wherever you live

But in general yes you can, it will need to be done by your attorneys.

Thanks for that. I checked with a free legal aid advice service available here in Australia and was told that it is possible for two people to be signatories on the same home mortgage document and for their percentage share to be different... as suggested by everyone here.

And yes, we use solicitors in Australia for drawing up wills, setting up trusts, mortgage documents, and to help with divorce settlement proceedings etc. If our solicitors are similar to your American attorneys, then they have the uncany ability to know your dollar worth to them in as much time as it takes to sniff, are masters at letting things drag on forever by keeping you guessing as to what each party is up to, and hooked into their game with a lot of legal-speak. We love them too :-)