Dutch architects MVRDV created a unique design for Amsterdam’s Alfabetgebouw, an office building for small and mid-size creative companies. On the building’s east side a series of dotted windows spell out the building’s street number, 52, and on the north side the shape of each window reflects the unit number of its tenant.

To make the alphabet fit on a 6 × 4 facade they had to omit two letters — but “the IQ is inside the building.”