The University of Central Lancashire is the latest institution to introduce fines for departments where academics have booked a room but have not used it.
UCLan is charging £50 for each booked room found to be empty during a twice-yearly audit.
The initiative highlights the squeeze that rising student numbers are putting on teaching space.
"Currently there are times when there is no general learning accommodation available anywhere in the university," a memo from the facilities management department says.
But an anonymous academic has written to The Times Higher to complain about the twice-yearly visits from UCLan's "very own Schutzstaffel ".
"Staff have just received one of their missives from the Obersturmbannfuhrer warning that her team of shock troops 'will be conducting a full audit of learning accommodation'," the angry academic writes.
A university spokesman said: "The fines are taken from departmental budgets, not individuals, and the money received is ploughed back into the continual upgrade of room facilities, so this has proved to be beneficial for the whole university community."
UCLan is not the first university to penalise staff for wasting space. City University began imposing fines of up to £500 for unused rooms after a survey revealed that 400 hours of bookings for rooms went unused while £800,000 a year was being spent on external room hire.
A recent report from the Higher Education Funding Council for England's space management group advises universities to use penalties and incentives.
"There could be fines for departments where there is a significant difference between scheduled and observed frequency of use," the report suggests.
Resistance to timetabling teaching sessions at the start and end of the day and room allocations based on staff preferences rather than need leads to a bunching of demand and an overestimation of the amount of space needed, the report says. It suggests using "differential charging for different times of the day or week".
"Premium rates are charged at peak times, with discounts for the least popular," it says.