Both you and the funding partners own part of a Limited Liability Partnership (LLP) which buys the home. If you buy 5% of the home, you own 5% of the LLP.
It’s the LLP (of which you are a partner) that is named on the title deed. You have full legal and beneficial ownership of the part of the home you buy, so if the boiler breaks, and you buy 5% of the home, you only pay 5% of the repair costs.
Likewise, if you and the funding partners sell the home, and you bought 5%, you would only get 5% of the sales proceeds.
Of course, this doesn’t stop you from painting 100% of the walls and planting trees in 100% of your garden!
When you buy more of your home, you increase your share in the LLP and, therefore, the home from as little as £50.