The foundations, as was traditional in medieval Moscow, were built of white stone, while the churches themselves were built of red brick (), then a relatively new material[REF] (the first attested brick building in Moscow, the new Kremlin Wall, was started in 1485) [REF].
The builders, fascinated by the flexibility of the new technology,[REF] used brick as a decorative medium both inside and outside, leaving as much brickwork open as possible; when location required the use of stone walls, it was decorated with a brickwork pattern painted over stucco [REF].