The NSW government has succeeded in its appeal against a landmark decision to block it from forcibly acquiring property from a developer in Sydney's inner west for the $16.8 billion WestConnex toll road project.

The judgment in the NSW Court of Appeal is a boost to the Berejiklian government's ability to compulsorily buy property for major projects in Sydney worth billions of dollars such as the Parramatta light rail line and the Prince of Wales Hospital redevelopment.

The Desane property, outlined in red, at the centre of the legal tussle.

It overturns a NSW Supreme Court decision in May that found Roads and Maritime Services' plans for a 5274-square metre property in Rozelle owned by Desane were ill-defined and “may never be realised”. The case centred on the validity of a proposed acquisition notice.

In the Court of Appeal judgment handed down on Thursday, the proposed acquisition notice issued to Desane by the roads agency in May last year for the property was found not to be invalid, and nor did it have to strictly comply with an approved form.