The new church, of St. Mark the Evangelist, is a complete departure from the customary plan used in the construction of Catholic Churches. This departure results from placing the Church proper, the Presbytery, and the Social Hall within a single unit. Although cruciform in design, the transepts are extended not unproportionately, however, so that while the one on the right houses the residence of the clergy, the one on the left is dedicated to the social life of the parish. Still, in spite of this unique feature, the beauty of the edifice is enhanced by its simplicity, proportion and straightforward design. It is distinctive in its complete lack of heavy ornament and cumbersome detail. The interior composition of the building invites peaceful concentration, without enticing distraction.
To harmonize with the semi-urban character of Lawrence Park, the designs modified English Gothic inspired by examples of rural churches in the Lowlands renowned for their beauty and simplicity. These churches, we should remember, are built low and are surrounded by spacious churchyards.
The entire exterior of the building is constructed of Briar Hill sandstone, quarried in a random ashlar of varied tone and cut to size in order to produce the desired effect. Very little stone trim is used around the building except over the windows and to mark the sills and doorways. Then a distinctive gray is used to set these off, by contrast. The roof is constructed of a varied shade of green asphalt shingles lending a rustic touch by their verdant hue. As the church is cruciform in plan, a proportionately high fleche of copper surmounted by a Maltese cross in gold leaf conveys a pleasant effect to the meetings of the various departments. The simple façade of St. Mark's, with pointed Gothic porch and lofty circular window, is equally attractive. Standing above the entrance is a Celtic Cross, chiseled from quarried limestone. The window spacing, in the nave, is high and rectangular. The entrances are low and the doors, hewn from medium oak, have their severity broken through the installation of varied colored lights. Antique Swedish iron light fixtures reach upward to provide illumination for the threshold, during evening services.