Developers building 128 new homes at a former animal rendering plant are under investigation by Lancaster City Council.
Barratt Homes have been accused of building a sales office without permission at the gateway to Quernmore Park - their new housing development at the former Nightingale Hall Farm.
The housing giant was given planning permission for the development itself earlier this year and began work last Saturday.
But a resident of the area said: “I called the (council) planners and they knew nothing about the sales office.
“You would think a builder would know to get planning permission.”
A spokesman for Lancaster City Council said: “The city council has received a complaint regarding the siting of the site cabin in this location.
“The cabin does not appear to benefit from planning permission and as such the council’s Planning Enforcement Team are investigating the matter further.”
A spokesman for Barratt Homes said: “We’ve been notified of the situation and we’re working with Lancaster City Council to resolve it.”
The controversial animal rendering plant in Quernmore Road closed following a fire in 2005.
Barratt Homes will build three and four-bedroom homes on the site. Work should be finished by next April.
The developer is also building 14 new four and five bedroom homes at Mill Lane in Halton, to be called Water’s Edge. They also began work there on Saturday.