Practically-minded women who may be considering proposing a joint house purchase rather than wedding bells this leap year are advised of a potential £30,000 dispute if they don't see a solicitor and draw up a "Deed of Trust" first, reveals the Woolwich, Barclays mortgage arm.

Andy Gray, head of mortgages for Woolwich and Barclays explained, "Cementing the relationship with a property commitment rather than a ring may be the modern equivalent of the 'leap year proposal' but it's essential that couples agree on the not so romantic outcomes such as who gets what share of the equity in the home if things don't work out."

The Woolwich investigated the kind of equity gains that unmarried couples, who have bought a property together, could find themselves disputing in the event of a split, as the law doesn't currently protect unmarried couples.

• The average cohabiting relationship lasts 19 months
• 19 months ago, the overall average purchase price of a residential property in England and Wales was £133,247
• Since then prices have increased by around 23 per cent to £163,584.
• Meaning unmarried cohabiters going through a "split" today would potentially need to agree the fair division of around £30,300 worth of equity in their co-owned property.

Andy Gray adds, "Even though the housing market is slowing we advise that couples plan ahead. A quick trip to a solicitor is a small price to pay to avoid potential stress and legal wranglings around money further down the road."

Unmarried couples should consider drawing up a 'Deed of Trust' which allows each partner to state the proportion of their holdings in the property. It could be important in determining the division of assets if the relationship ends, especially if the partners are not contributing equally to the deposit or the mortgage repayments.