The following is a description of the plans for the Mount Vernon Congregational Church provided by the architects, Walker and Kimball, and quoted by the Boston Globe in its November 5, 1891, article on the laying of the corner-stone for the church.
“The church building will occupy a ground space 92×130 feet. It will have three facades. The principal one will be on Beacon st., where will be a triple entrance-way, the gable above which will be pierced for a rose window.
“A square tower will rise at the West Chester pk. and Beacon st. corner to a height of 85 feet, and will form the base of a 45-foot octagonal spire.
“The walls of the building will be of Roxbury stone, with buff Amherst stone trimmings.
“The West Chester pk. front will have the appearance of a double transept, with entrance way between the two. Both the transepts will have two-storied triple arched windows with rose windows in the gables above.
“On the river front, the north side, it will be also two-storied and have three stone dormers.
“The interior of the church will be on a cruciform plan.
“The nave will be 60 feet in width and 79 in length. The transepts will each be 30 feet wide and 13 feet deep.
“The organ gallery will be on the east transept.
“The roof will be supported by hammer beam trusses. The ceiling will be sheathed in ash. The distance will be 50 feet from the floor of the church to the peak of the roof.
“The north transept will contain on the first story, a vestry and four class-rooms, so arranged that the wall partitions can be pushed up and all the space thrown into one apartment.
“The second story of this transept will contain a dining room 30×50 feet. It will have an open timber roof, and there will be adjacent ladies’ parlor, minister’s room, kitchen, pantries, dressing rooms, etc.
“At the north end of the church roof will be placed a tall copper ‘fleche,’ into which will be carried all the ventilation ducts.
“The height of the exterior walls will be 20 feet in the church walls proper and 32 feet in the transepts.
“The interior finish will be in ash, with floors of hard pine.”