The a+t research group evaluates every project through two key parameters that shape desirable housing: Privacy and Exteriority.

On the front of each card, a plan drawn at 1:1000 or 1:1500 scale shows the estimated level of Privacy based on:

• vertical circulation cores
• horizontal circulation area
• actual building heights
• number of dwellings per floor

On the back, a unit drawn at 1:300 scale illustrates its level of Exteriority according to:

• proportion of outdoor space
• proportion of façade
• number of orientations
• window widths
• depth of the dwelling

Units are presented in both metric and imperial systems.
The card-deck format (13×8 cm / 5×3 in) allows quick comparison and helps identify the strengths of each plan and each unit at a glance.

The a+t card collection is part of the Density series, launched in 2002 and recognized worldwide as a leading reference in collective housing research.