Home owners who challenged in court the compulsory purchase of their property by government agencies tended to receive payments larger than what they were offered previously, according to an analysis by the NSW Parliamentary Research Service.

The service's analysis, which is disputed by the Office of the Valuer General, attempts to shed light on a growing area of controversy in Sydney and NSW.

The issue of compulsory acquisitions has come to the fore due to the significant number of road and rail projects being built by the state government, many of which require the purchase of homes or units for construction.

According to the Research Service's analysis of figures from the Finance Minister, Dominic Perrottet, there have been about 2970 compulsory acquisitions in the past eight years. Over 80 per cent of those were concluded by agreement between the agencies buying the property – such as Roads and Maritime Services or Transport for NSW – and the property owner.