Future buildings overhead Broadway Subway station entrances possible

May 8 2021, 2:15 am

There has been chatter over social media for the past week on the desire to not waste valuable air space over the station entrance buildings for SkyTrain’s Millennium Line Broadway Extension.

The above-ground designs of the entrances for the six new subway stations are currently undergoing a new round of public consultation.

So far, one common critique is that most of these entrances are only single-storey structures, with nothing above — such as a mid-rise building with residential and/or office space.

Some have also suggested such multi-storey buildings should be built concurrently with station construction.

mount pleasant station skytrain broadway extension

SkyTrain Mount Pleasant Station design concept, April 2021. (Government of BC)

oak vgh station skytrain broadway extension

SkyTrain Oak-VGH Station design concept, April 2021. (Government of BC)

The only two exceptions are South Granville Station and Great Northern Way-Emily Carr Station.

South Granville Station will be built into a private five-storey, mixed-use development by PCI Developments with retail and office.

Construction on this building is well underway after a simple development permit application was swiftly approved, but the developer is anticipated to return to the municipal government in the near future with a rezoning application for added floors for residential or extra commercial density.

The five-storey building at South Granville Station is currently being built to accommodate this eventual vertical expansion; there will be six underground levels of parking and an extra elevator core to serve an overhead tower.

south granville station skytrain broadway extension

SkyTrain South Granville Station design concept, April 2021. (Government of BC)

1465-1489 West Broadway Vancouver South Granville Station

Artistic rendering of Broadway Subway’s South Granville Station integrated into 1465-1489 West Broadway, Vancouver. (Musson Cattell Mackey Partnership/PCI Developments)

Over at Great Northern Way-Emily Carr Station, the latest artistic renderings depict a future mid-rise office building straddling over the station entrance.

Similar to the Canada Line stations, the designs of the Broadway Extension stations are fairly simple to allow for the relative ease of integration into adjacent and overhead developments in the future.

“A key design principle for the new Broadway Subway project stations is to maximize potential for future developments above and/or around the station entrance buildings,” reads a statement from the BC Ministry of Transportation and Infrastructure to Daily Hive Urbanized.

“Simple, linear roof forms and station shapes, and incorporating ‘knock-out’ panels will help easily integrate the buildings with future developments.”

Great Northern Way-Emily Carr Station skytrain broadway extension

SkyTrain Great Northern Way-Emily Carr Station design concept, April 2021. (Government of BC)

Great Northern Way-Emily Carr Station skytrain broadway extension

SkyTrain Great Northern Way-Emily Carr Station design concept, April 2021. (Government of BC)

For the block-sized site where the existing entrance into Broadway-City Hall Station is located, the City of Vancouver has plans to redevelop this longtime city-owned property into a new future city hall campus. Planning work for this expansion of city hall is delayed due to the pandemic.

The Broadway Extension will share the same entrance as the Canada Line at Broadway-City Hall Station, but there will be a small eastward expansion of the building to accommodate a surface-to-underground pathway. Schematics for this expansion show a “knock out” panel that would enable a direct entrance into the station from the adjacent city hall development.

broadway city hall station millennium line skytrain

SkyTrain Broadway-City Hall Station design concept, April 2021. (Government of BC)

To fulfill the subway’s requirements, TransLink and the provincial and municipal governments acquired numerous properties along the route. The largest of the acquisitions was for Mount Pleasant Station — the southwest corner of Main Street and Broadway, where most of buildings on the block were recently demolished.

For South Granville Station, TransLink and the municipal government acquired a large mid-block site immediately east of the PCI Developments building footprint and station entrance. This mid-block site between Granville Street and Helmcken Street will be used for the construction staging and storage space needed to build the subway station.

It is important to note that the station entrance buildings will only occupy a small fraction of the footprint that was acquired. Over the next five years, these large sites will double as critical staging and storage space for station construction, thereby reducing the need to close more road space, which would only result in greater impacts to traffic including the reliability of the 99 B-Line during the construction period.

Broadway City Hall Station Millennium Line Broadway Extension

Location of Broadway-City Hall Station, with the station entrance building and construction staging/storage areas highlighted. (Government of BC)

Mount Pleasant Station

Location of Mount Pleasant Station, with the station entrance building and construction staging/storage areas highlighted. (Government of BC)

Location of South Granville Station, with the station entrance building and construction staging/storage areas highlighted. (Government of BC)

As a lesson from the disruptive practices of the Canada Line, there is an effort to take the construction footprint of the Broadway Extension away from roadways as much as possible, which is largely achieved by using tunnel boring machines. But some construction from the road surface is still required for the large underground station structures, which are double the size of the Canada Line.

Two lanes of traffic will be maintained in each direction for buses and other vehicles at the station construction sites, except for the intersection of Broadway and Main Street (Mount Pleasant Station) due to the narrower street width. Along other areas of Broadway on the subway route, three lanes of traffic in each direction will generally be retained, including one lane each way for buses.

This makes the idea of concurrent construction of residential/commercial buildings overhead the station entrance buildings challenging, and even if this approach were pursued it would greatly complicate the scope of the $2.8-billion project and could put its timing for a 2025 completion and opening at risk. More properties would have to be acquired for staging and storage areas; soaring land acquisition costs are one of the primary factors for the project’s cost escalation, up from $2.28 billion in 2015.

Arbutus Station Millennium Line Broadway Extension

Location of Arbutus Station. (Government of BC)

At some point in the future, the staging and storage areas at most station locations will be developed into buildings. The one exception is Arbutus Station, which is enclosed by the new bus exchange for the truncated 99 B-Line to UBC.

In addition, transit-oriented development opportunities along the Broadway Corridor have been greatly limited by the temporary moratorium on most types of rezonings during the municipal government’s Broadway Plan planning process, which is greatly delayed and not expected to produce a draft plan for city council’s review until late 2021.

To date in this region, there has been just one instance of an overhead building added to an existing subway station.

The Canada Line’s King Edward Station entrance building was built for an overhead addition of a three-storey, wood-framed building. But the private developer overcame the engineering challenge of building a taller structure by cantilevering the floor slabs above the station from the building’s concrete core. With this method, no structural elements or additional supports were required for the station, which remained fully open during construction.

Cambie Star, the name of the seven-storey residential and retail building straddling over King Edward Station, reached completion in 2017, about eight years after the opening of the Canada Line.

An online survey on the Broadway Extension’s above-ground station entrance buildings will remain open until May 12, 2021.

2014 condition of King Edward Station:

canada line king edward station

Canada Line’s King Edward Station in 2014. (Google Maps)

2017 condition of King Edward Station with Cambie Star addition:

King Edward Station Cambie Star

King Edward Station with its new bike parkade and the Cambie Star building in 2017. (Jeremy Segal/W.T. Leung Architects)

Kenneth ChanKenneth Chan

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