The National Trust is inciting a backlash against the proposed redevelopment of the Hotel Windsor in Melbourne’s Spring Street.

The trust is railing against the demolition of a significant portion of the historic hotel and the addition of a 25-storey tower.

Designed by Denton Corker Marshall the tower is intended to act as a ‘curtain’ that drapes behind the 19th century building. Instead, the trust claims, it will be “a dominant element looming over the historic landmark”.

The designs “lack sympathy” and threaten the intimate scale of the Bourke Hill precinct, claims the National Trust.

While Denton Corker Marshall’s design is innovative and “visually light”, the owners bought the building knowing full well it was on the Heritage Register with a height limit of 23 metres, and the development should be stopped, the trust argues.

“The innovative wavy all-glass wall, moderated with white ‘fritting’, creates something more akin to sculpture than a standard high-rise building. But as a pair, the proposed tower and corner building would dominate what would be left of the historic Windsor hotel.”

The trust is calling for the landmark tower to be cut by two storeys to match the existing buildings in the area. It has set up a Save the Windsor website on which people can sign a petition that will be sent to the Lord Mayor, Heritage Victoria and the minister for planning.

A statement of impacts of the new design by Lovell Chen heritage consultants said the development “has been approached and designed in a manner which seeks a balanced outcome in which key heritage values of the place are maintained and its future as a grand hotel better assured”.

“The Windsor is the last of the grand heritage hotels in the country. Melbourne’s already lost five. So this development is a means by which its future can be assured,” Bill Corker of Denton Corker Marshall told Architecture & Design.