These five perspectives are all taken from the same angle, and offer slightly differing versions. These are also the first opportunity to see Soane's ideas for the exterior of Holy Trinity. Doric was the chosen order, with a tri-portal entrance. The flanks would be nine-bays in length. On some examples, banded masonry was placed, and sculpture panels. There would be two side entrances with a columned porch on each side. There is variation is the attic roof which was initially low, then disappears only to reappear in a grand manner, which Carr interpreted as the birth of a clerestory level (1976, p. 344). A triform base on the front of the roof above the principal entrance would support a tower placed towards the front of the roofline. Statues would surmount the dome.

This is contrary to Soane's thoughts about the location of spires and towers. In his Royal Academy lectures he stated:

When spires unite and make a part of the buildings they accompany, they are entitled to all the praise...but when instead of rising, as it were, out of the ground, they take their bases on pediments of porticoes, and upon the tops of roofs, as at the church of St Martin-in the Fields..., and many other examples, no elegance of form, no variety of outline, can make such compositions at all bearable. Spires blended with towers, domes and other objects of different heights...when seen at a distance, strike us most forcibly...but as we approach nearer, and find these objects unsupported and seeming to grow out of pointed roofs these pleasing sensations gradually subside, and end in disappointment (Lecture VI, in Watkin, 1996, pp. 569-570).

Nevertheless, visits to churches such as St Martin-in-the Fields, St James' Piccadilly, and St John's in Egham may have influenced Soane when having to produce a church tower under budgetary constraints, although here it seems Soane recognized early on that due to such budgetary limitations, it was impossible to construct both a pediment and tower.

Statues surmounting the dome may have indicated early enthusiasm to adorn the Church with more ornament (also note sculpture panels on the end bays on all but SM 54/3/7, and all have sculpture panels on the base of the tower). Figures surmounting the dome can be seen on an early design for a church in Marylebone by one of Soane's tutors and mentors, Sir William Chambers, which is in the Soane collection (SM vol. 156/63), and Soane himself used this motif for his unexecuted Sepulchral Chapel at Tyringham Hall. Perhaps the closest model for this tower is the rotunda for the first-century Roman Tomb of the Julii at Saint-Rémy in southern France which has the statues are within the rotunda, while Soane decided in his example to transfer them to the pinnacle of the dome.