The question as to the original plan of the Erechtheum follows naturally the interpretation of the building as built. That the west wall was planned for its present place seems improbable for a number of reasons. The north porch is out of proportion to the room into which it opens, and by reaching beyond the west wall of the temple becomes in part porch to an open precinct. The west front has columns and Caryatids at different levels (Dörpfeld, _Ath. Mitt._, 1904, p. 101). The displeasing effect of this difference could not have been concealed by the walls of the Pandroseum, the south one of which reached as high as the parapet of the porch of the maidens. The latter porch illustrates the skill of the architect in concealing differences of level. The unique closed wall on which the maidens stand was his device for concealing from view from without, a door which was below the level of the porch and which belonged to the interior whereas the porch belonged to the exterior. The architect, by placing the entrance to the porch at the north east corner close to the wall, completely concealed the presence of the low door. With this care to conceal a difference of level, the west side of the temple is in marked contrast.
The north-west corner of the western cella is peculiar in two ways. The western jamb of the door cuts 3-1/2 cm. into the west wall of the temple. This suggests crowding and is satisfactorily explained by the condition of the foundations below. The foundation of the west wall does not key into that of the north wall (Fig. 11), a fact seeming to prove that when the latter foundation was laid, it was not the intention of the architect to place a foundation in the line of the present west wall, and to crowd the door jamb into that wall.
Of the symmetrical exterior proposed by Prof. Dörpfeld there lies a suggestion in the fact that the north and south doors have the same axis, although the Caryatid porch has not. The porch seems to have been moved a little to the east of its intended place that it might not project beyond the west wall, but not far enough to prevent the cornice of the porch from so projecting.
The west wall itself offers evidence of a curtailment of the original plan. By way of introduction let us compare the east façade, which is Greek with the west façade, the part of which above the closed wall is Roman (_Arx Athenarum_, Pl. XXV, D, and _A. J. A._, 1906, Pl. VIII). The windows in the east wall which Stevens has determined with accuracy were placed at the height of four ordinary courses above the base moulding and two courses from the top of the wall, just as were the Roman windows in the west wall. The second course above the eastern windows was a moulding, the corresponding course above the western windows is plain probably because of the adjacent capitals. Below both sets of windows were three courses of blocks. In the east wall orthostates were justifiable, in the west wall they would have been illogical because on neither side was there a floor, but three courses equal in height to four ordinary courses were placed there. Stevens has shown that the eastern windows were seven courses high including the lintel. The western windows are five courses high. The explanation of the difference of height is simple. The eastern wall was thirteen courses high, the western eleven. The western windows were two courses shorter in order that they and their counterparts, the eastern windows, might be equidistant from the base of the wall, namely four ordinary courses, and from the top of the wall, namely two courses. The fact that the sills of the Greek windows were one meter lower than the Roman windows is of no consequence whatsoever. The fact of great importance is that the east and west windows occupied the same relative position in the façade. The stylobate of the western façade could not be placed so low as the eastern because of the door and the necessity of a heavy block three courses high at the south end of the wall. This block could not be placed lower because of the Cecropium (= temple of Pandrosus?) which crossed the line of the wall, to judge from the cuttings in it beneath the heavy block. Had the architect wished equality of height for the eastern and western colonnades he would have been compelled to place the stylobate of the western two courses lower. This would have made it impossible to place a door in that wall which was necessary probably for a reason of cult.