It used to be that roofs were up top where nobody could see them, covered in gravel and full of mechanical equipment. Architectural renderings were pretty much all shot from eye level. Not anymore; green roof technology is making roofs into habitable architecture, and changing the way architects think of buildings.
The Express Rail Link - West Kowloon Terminus by Aedas will connect Hong Kong to the National High Speed Rail Network. The terminal's roof is a series of ribbons that meet ground level, turning the building into a big walkable (climbable?) hill.
The architects tell Designboom:
Flowing ribbon pathways spread to the roof plane, morphing into a highly sculpted garden. atop the 25 to 45 meter tall volume, an observation platform along the south elevation directs views towards the skyline, Victoria Peak and encompassing landscape. The roofscape circulation will link to retail and nearby subway and public transit points. Voids and apertures within the facade bring daylight as well as visual glimpses down to the sub-grade platforms.
The have green walls inside the terminal, too. I wonder how many people will slog up those ramps, that look more like hills and must break every rule about maximum slope. But I do like the trend of roofs becoming public space.