A system of charges or fees related to the use of girders or the structural support elements in a building, or payments for installing and maintaining iron girders.
From 'girder' (iron support beam) plus '-age' (a suffix indicating a system, collection, or set of charges), used in architectural and construction fee contexts.
This is a beautifully specific historical term from when cast-iron girders were revolutionary building technology—contractors would charge 'girderage' the way we now charge for steel reinforcement.
Complete word intelligence in one call. Free tier — 50 lookups/day.