Modern masonry?
Most buildings have walls 2 bricks and insulation thick.
one brick around 1.8 to 2mm, air gap 0.5mm Insulation around 1mm thick and another layer of brick,
the whole thing around 5 to 6mm.
If its a taller building there will be columns, in europe and UK this will probably be concrete with reinforcement bars, in the US probably steel with thin coating of concrete.
Bricks should be 4.3mm long, 1.5mm high, 2.05mm thick at 1/50 which is close for Hasslefree figures (these include the mortar thickness which normally would be 10mm thick in real life, or 0.2mm thick at 1/50, a score line should do it)