Problem
Totalitarian, machine buildings do not require trim because they are precise enough to do without. But they buy their precision at a dreadful price: by killing the possibility of freedom in the building plan.
Solution
Wherever two materials meet, place a piece of trim over the edge of the connection. Choose the pieces of trim so that the smallest piece, in each component, is always of the order of 1/2 inch wide. The trim can be wood, plaster, terracotta…
Related Patterns
… and this pattern finishes the joints between Soft Inside Walls (235), or Lapped Outside Walls (234) and the various floors and vaults and frames and stiffeners and ornaments which are set into the walls: Box Columns (216), Perimeter Beams (217), Floor-Ceiling Vaults (219), Frames as Thickened Edges (225), and Ornament (249).
In many cases, you may be able to use the trim to form the ornaments - Ornament (249); and trims may occasionally be colored: even tiny amounts can help to make the light in a room warm - Warm Colors (250).
Alexander, Christopher. A Pattern Language: Towns, Buildings, Construction. Oxford University Press, 1977, p. 1112.