Transit projects, both proposed and underway in the GTA, will boost real estate values in surrounding areas by as much as 20 per cent, says a new report.

According to the 'GTA Transportation Effect' report, the expansion of the Toronto Transit Commission's Spadina line to Vaughan will be the "leading catalyst" to population growth and property demand for the area.

The new line, which is expected to be completed by 2014, will extend to York University and end at the Vaughan Corporate Centre -- to be built on Highway 7, west of Jane Street.

The impact of the new line will influence property values in the area until at least 2020, says the report.

In Scarborough, three new or recent TTC and GO Train improvements will have a "strong positive impact" over the next decade on surrounding areas.

The TTC has proposed extending its 'Rapid Transit' system from McCowan station to Sheppard Avenue.

Meanwhile, proposals have also been put forward to extend the Yonge Street portion of the TTC line, which currently ends at Finch Avenue, to Steeles Avenue and into York Region.

The line will most likely end at the Richmond Hill Centre Terminal of VIVA (Bus Rapid Transit), located at Yonge Street and Highway 7.

The report, which was conducted by the Real Estate Investment Network, says values in older and more established neighbourhoods are impacted more significantly than in newer developments.

Additionally, it states that the value impact is felt most strongly three years after a transit station is opened.

In similar studies around the world, the report says real estate values increased for properties located within 500-800 metres of stations on new transit lines.