A leafy, historic 10-acre site on the corner of Granville Street and West 57th Avenue is slated for development with two towers proposed at 13 and 14 storeys.

Bruno Wall, president of Wall Financial Corporation, says the development and real estate firm hopes to submit a rezoning application for Shannon Estates to the city, within two weeks, with the help of architectural firm Busy Perkins and Will, within two weeks.

Building heights were a key concern raised at a meeting between Wall, the architect, a city planner, residents of Shannon Estates and representatives of the Arbutus Ridge/Kerrisdale/Shaughnessy Community Vision Committee July 21.

"That's one of the balancing acts between height and density and site coverage," Wall said. "Clearly the more open space you can have, the more height you need to achieve that."

The 14-storey residential building is proposed for the corner of Granville and 57th, and the 13-storey building for the middle of the large site. The development would include other buildings tiered from four to nine storeys. The property's grand brick Beaux Arts mansion with its stone columns, lofty porticos and ceilings and interior woodwork will be preserved along with the old coach house, the gatehouse and the property's heritage-listed perimeter wall.

The mature trees that screen the site will stay, and a parkade will be constructed around the city's heritage list-protected Copper Beech trees.

"Back in the '70s when Peter [Wall] developed the site, he actually moved 50 or a hundred trees in order to preserve them," Wall said. "And now we're going to do it again."

Wall's uncle Peter Wall had Arthur Erickson and Geoffrey Massey's architectural firm design the two-storey apartment buildings and low-rise townhouses that surround the mansion, the grounds, and a year-round outdoor pool and hot tub, in the 1970s. The residential development caused much anxiety in the area when they were built.

The old apartments and townhouses would be replaced with 800 residential units, including at least 200 units of market rental, an increase from the present 162 rental units. Whether they'll be modest or high-end rentals has yet to be determined, Wall said. Wall Financial isn't planning to apply to the city's program that provides relaxations to developers in return for constructing market rental.

Karl Brodhecker, who's rented at Shannon Estates, or Shannon Mews, as it's known, for seven years, expects he won't find such a spacious apartment, green space and pet-friendly environment when redevelopment forces a move. He joined the city's ARKS committee last year to try to ensure the development suits the site with its circa early 1900s Italianate-style lawns and terraces, fits the neighbourhood, respects the heritage features and the residents who will have to move.

"They've done a fine job of integrating the garden aspect of the property with the footprint of the buildings," Brodhecker said. "My personal opinion is that the heights are excessive for the neighbourhood and that's going to create a very high density nexus in the neighbourhood right here on a busy intersection, as it is."

Wall said the city has advised closing the traffic access points on Granville and Adera Street to the west, and having traffic enter and exit only off 57th.

crossi@vancourier.com