For these chapels, Plečnik opted for a rare motif of a house within a house. Above the chapels extends an arcade with cross rib vaulting comprised of twelve pilasters and a flat roof. The semi-circular section of the arches is decorated by ornamental metal tendrils similar to those planned for the Plečnik's unrealised Butchers' Bridge. Framed Latin inscriptions are chiselled in the stone before the entrance to the chapels.
The interior of both chapels is of light pastel colours, adorned with multi-colour trims. The prominent piece on the wall of the Chapel of St. Joseph is the cross with extensive metal base and marble elements, and the ball-shaped chandelier with a cross amongst tubular lamps. The Chapel of St. Andrew has no cross and is fitted with a more modest chandelier shaped like a prehistoric urn.