A distinct outline is missing from the Vancouver skyline: the living landmark that stood atop a condo building in the West End.

A pin oak has stood tall over the city since 1987, perched 17 storeys up on a building near Stanley Park.

In a city known for its verdant canopy, the tree was its single most-memorable for many residents and tourists.

But those who frequent the area have noticed that the tree is no longer there.

"We miss that tree. It was an icon of the West End community," said Britt Jacob, who lives in the neighbourhood.

"I'm really bummed because I used to sit in that hotel room and look at that tree," tourist Patty Grenqiust said.

The leafy giant is being replaced, but it won't come cheap.

Ron Rule was the original landscape architect, and has been quietly working on a replacement plan for more than a year, following the prolonged drought in the summer of 2015.

He said the building was designed for the tree by architect Richard Henriquez, but it's been 30 years and there were some issues caring for the oak.

"There was some water restrictions and it went three months without water," Rule told CTV News.

But he said the massive bowl holding the soil and tree needs to be re-waterproofed anyway, so "maybe it's a blessing in disguise."

The process to replace the tree is, understandably, more complicated than replacing a tree in a more traditional setting.

First, 130,000 pounds of soil must be removed from the roof. Then the membrane will be replaced, and a crane will hoist up a new oak.

The costs for the endeavour are staggering. Including labour, engineering, materials, scaffolding, fees and taxes and more, the final bill is estimated at $554,000. And that total doesn't include the cost of the tree itself.

Strata documents obtained by CTV show the owners of the building's condos have no choice in the matter. The city's building permit was contingent on having a rooftop tree, so owners will have to pay about $35,000 per unit for its replacement.

A mature 25-foot-tall, 12-foot-wide pin oak is already being prepared to take up its perch overlooking the city of glass.

"We're going to plant it in the fall, which is the best time to plant a tree like that," Rule said.

"It's going to have better lighting, better soil. It's going to be treated well."

The tree weighs between 12,000 and 14,000 pounds. Rule said his team looked very extensively for the right tree for the space, 200 feet above the ground.

They found the tree about a year ago, and it's been carefully pruned and taken care of in the months since.

"This tree represents the top of the rain forest, or what the Douglas fir or cedar trees would ultimately reach in height," he said.

They settled on a pin oak because firs and cedars wouldn't be able to handle the wind loads that deciduous trees can take. Most of the pin oak's weight is at the bottom of the trunk, its branches are light, and the species was able to withstand the windstorms that whipped through Vancouver in late 2006, uprooting thousands of trees in Stanley Park.

With a report from CTV Vancouver's Penny Daflos and Shannon Paterson