The question of flexible spaces has always been a difficult one. Mainly, flexibility was defined by constraints. An architect, developer, city planner of someone else defined either a function, the size or the partitioning.
There have been quite some developments around the theme of flexibility, but none of them have been as radical as the concept of solids in Amsterdam.
Solids are about complete freedom, and complete flexibility. Tennants are free to decide the amount of square meters they want to rent - with a minimum of 90 m2. So far, nothing radical. However, tennants can also freely decide what they want to do with those square metres. If they'd like to use it to live in, it's just as good an option to start an office in the building. Pretty much everything goes, as long it doesn't cause disturbance for the neighbors (be it noise, pollution or whatnot).
That's what makes the concept of Solids so interesting: the building gives way to a mixture of functions, even if it isn't completely planned in advance. The buildings live, change and are adaptable to whatever the users would like. This also means that the spaces are completely empty and free of any interior obstacles. There's a front door, a wall and a facade and electrics, gas and water. All the interior walls, bathrooms, and furnishing can be decided by the tennant, and changed at will.
This way, the chance that the building becomes obsolete within some years of construction is pretty small. If there's a bigger market for dwellings, more of the casco spaces will be used as appartments.
A lot can be said about the currently planned Solids - about their facades, about their location in the city and what that means for the possible programming, the connection with the urban tissue, etcetera: but that's not quite the most fascinating part of this concept. The thing is: the appearance of the facade is literally only skin-deep. What makes the concept fascinating is it's flexibility in all senses. Even the rental price is to be decided by the tennants (within some reasonable ranges, of course)!
The concept of Solids is developed by Stadsgenoot, by the way.