The owners of two eyesore seafront properties in Hove have been served with enforcement notices.
And a third site is being targeted by planning officials.
Brighton and Hove City Council said that officers had repeatedly been in touch with Stranmede, the company that owns 149-151 Kingsway, Hove.
The council said that it had asked Stranmede to repair the derelict-looking semi-detached properties, improve their appearance and clear clutter from their gardens.
Having been ignored, officials have now served a notice giving the owner six months to carry out the works specified by the council.
The council said that a notice had also been served on Maria Holliday in relation to Lawnscroft at 155 Kingsway, Hove.
The owner had agreed to demolish the former nursing home by the end of last month and begin building on the site.
It has planning permission for a new 30-bed nursing home but no action has been taken.
Council leader Mary Mears said: “I am pleased with the action that has been taken by the planning enforcement team to improve the appearance of these properties that are a blight on the appearance of the seafront.
“Officers have been very fair by giving the owners every opportunity to submit planning applications to redevelop the properties but unfortunately the owners have not shown the same level of goodwill.
“Officers have been left with no alternative but to take this formal action.”
The council said that it was also talking to the site owner of the former Sackville Hotel and had requested that it clean up the site while it was preparing to seek permission to redevelop it.
