The imposing British Columbia Parliament Buildings have a fatal weakness: they could collapse in a major earthquake.

The legislature, as the buildings are more commonly known, was built long before modern seismic building codes were adopted. Engineers have identified its iconic dome above the centre block as being particularly vulnerable to damage.

Fixing the century-old structure would be expensive with past estimates pegging a retrofit at somewhere between $700 million and $900 million.

B.C. Parliament Buildings

Construction on the British Columbia Parliament Buildings was initially completed in 1897. (Gregor Craigie)

But now the Speaker and legislative officers are working on a proposal that could lead to the construction of a new seismically-robust back-up building.

Craig James, a legislative clerk, said such a plan could draw inspiration from a historic architect.

Francis Rattenbury gained fame in the early 1900's for a number of landmark buildings, including the B.C. Parliament Buildings and the nearby Empress Hotel. 

"One option that we have is to take one of Rattenbury's drawings to replicate a portion of this building over there, which in looking at it would be spectacular," said James.

The Armoury behind the B.C. Parliament Buildings

The Armoury building behind the B.C. Parliament Buildings is the proposed site of a seismically-robust back-up venue for MLAs to meet. (Gregor Craigie)

The proposal would see the old brick armoury building that currently stands behind the legislature torn down to make way for a new building. 

"That building would in some part replicate on a smaller scale this place," James said. "But also a larger chamber could be built over there so that in the event that something did happen here and this place was unusable, perhaps we could use it."

Of course, government does not need an ornate legislative assembly to function. And building a back-up legislative assembly would not be cheap, likely costing tens of millions of dollars. But James notes that is about one-tenth of the cost of retrofitting the legislature itself.

Gary Lenz, the sergeant-at-arms, says ensuring continuity of government and a rapid response to an emergency are important. 

"We all form that linkage towards passing of bills and legislation, which is critical if there's a major earthquake or there's a major disaster in the province."

One of the Statues on the B.C. Parliament Buildings

Legislative staff are working on improving the earthquake response plan, including better securing some of the statues atop the building's exterior. (Gregor Craigie)

Speaker Darryl Plecas said a new building would play a crucial role in an emergency, and would also make the eventual seismic upgrade of the legislature more feasible.

"We could really be helpful in two ways. One is we help ensure continuity of government because we have a place for people to work. And then we have a place to work whilst we were doing seismic upgrading, so we provide for an enhanced level of safety along the way."

In the meantime, legislative staff are working on improving the earthquake response plan, including better securing some of the statues atop the building's exterior.

Other measures already in effect on the grounds include early warning sensors and accessible containers with emergency supplies. 

Staff also hope to have early warning apps installed on mobile phones belonging to legislature employees within the coming months.