Los Angeles architecture firm Populous and developer Oak View Group (OVG)  announced a major $660 million renovation on the Seattle KeyArena that will double its interior space and still keep its iconic 60s-era roofline.

The renovated arena will have a glass atrium and club space on an upper-deck. Construction is scheduled to begin in October and will last approximately two years, although a contractor has yet to sign onto the plans.

OVG committed to covering any budget overages, and set aside $40 million for transportation and $20 million for community benefits in two funds. Furthermore, OVG promised to sign a nearly 40-year lease, and will put a floor on rent equal to the arena’s current revenue.

The innovators at Populous are looking to dazzle Seattle natives and tourists. They draw on experience from a Madison Square Garden Co. project in Las Vegas, the MSG Sphere Arena, which is also in the planning stages.

Although there is still plenty left to be done, the project’s ambition, scale and respect for its architectural origins are already impressive.