Mental health services for adults across Nottinghamshire could move from a site which "falls short of standards" by next spring, if plans are approved.
Millbrook Mental Health Unit, based at King's Mill Hospital in Sutton-in-Ashfield, provides clinical support for adult and elderly people with mental health issues.
Bosses at Nottinghamshire Healthcare Trust, which runs the service, says some aspects of the unit are "not fit for purpose".
They now plan to relocate to the site of the soon-to-close St Andrew's Healthcare at Sherwood Oaks Business Park, Mansfield, which supports people with learning difficulties.
Concerns have been raised about the quality of Millbrook's adult mental health services, particularly on its Orchid ward which currently exceeds recommended ward sizes.
A report into the move, which will be discussed by Nottinghamshire County Council on February 25, says the 78-bed cannot be "assured as compliant" with Care Quality Commission standards.
Under the move, adult mental health services would move to the St Andrew's site, while services for older people would remain at the Millbrook site.
The report says Nottinghamshire Healthcare explored four options for the transfer of care, including refurbishing the Millbrook site, building a new site, or subcontracting the services to another provider.
However, it deemed refurbishment unaffordable, bringing "significant disruption for patients" during the works. The option for a new-build site was also discounted due to high costs and because there is no suitable locations in the area.
This meant the purchase of St Andrew's Healthcare was the "only available" option to the trust, due to its location, size, financial value and because it was being vacated.
The report says: "The trust has acknowledged that the care environment at our Millbrook site falls short of the standards required to deliver high quality, therapeutic care.
"The acquisition of the Mansfield site from St Andrew’s will provide a solution for adult mental health services, which are the highest priority for the trust due to concerns regarding the existing wards at Millbrook.
"Mental health services for older people will remain at the Millbrook site but will benefit from being able to move into the Lucy Wade ward, once vacated by AMH. That ward is on the ground floor and was recently refurbished to provide 16 single en-suite beds.
"This will deliver significant improvements for older people cared for on the MHSOP (mental health services for older people) wards and for the staff that work there."
The 64-bed St Andrew's site provides secure support for men diagnosed with learning difficulties, with plenty of outdoor and leisure space.
Bosses at St Andrew's want to move these patients out of secure care, with plans to close the site and support patients "in a less restrictive setting".
Katie Fisher, St Andrew’s CEO, added: “By making this change we will reduce the number of people with autism and learning disabilities who are living in secure care, and increase the number of individuals supported within the community."
