Bournemouth Civic Society has said plans to rebuild Lansdowne Baptist Church should be put on hold for further discussion.
The church plans to spend £3m rebuilding the church to provide modern facilities and an auditorium accommodating up to 1,000 people.
Comments by the Civic Society say the design of the building would be “austere” and that its “rather forced asymmetrical design” would not be “overtly offensive” but would be “quite easily forgettable”.
The society added: “We are therefore convinced that the extensive survival of the surrounding late Victorian commercial architecture of the area demands a more sympathetic design than what is proposed.”
It said the council’s planning board should defer a decision on the scheme to allow further discussion.
Councillors have yet to consider the application at a meeting.