Shrewsbury Civic Society wants to protect various "non-designated heritage assets" which do not have the benefit of national listed status, such as the town's Shirehall.
Some local authorities have their own lists of non-listed buildings they aim to protect, but Shropshire does not, and the society says that puts many locally important buildings in peril.
Jordanis Petridis, who is leading the initiative, said: “Please report to the civic society any important buildings which you believe to be a threat of losing them, or buildings of quality which may deserve to be listed."
Shropshire Council was granted an immunity certificate to stop Shirehall receiving listed status, therefore making it more attractive to potential buyers who would have more freedom to demolish the building and develop the site.
The council will vacate the building and is planning to move to a new town centre location, expected to be the lower level of the Pride Hill shopping centre.
Shirehall narrowly missed out on national listing status, being described as a "striking building of some distinction".
The Monkmoor Second World War hangars are also one of the civic society's priorities to protect.
They were saved from demolition in 2016, but a planning application has just been submitted that the society says would compromise its roof of Belfast trusses, and potentially the structural soundness of the building.