The phrase 'has not been maintained' is correct and usable in written English.
You could use it in a sentence such as: "The condition of the building has not been maintained over the years."
Charles was said on Wednesday to be "disappointed" that his confidentiality has not been maintained.
30 March: "The slight improvement in his condition has not been maintained.
They will also learn how to deal with challenges associated with handling vacant properties, like pools the color of pea soup (the color they turn as algae takes over a pool that has not been maintained), as well as what to do when they find a vacant home with abandoned pets.
To date, this promise has not been maintained, despite the appearance of new attractive cell populations for grafting, such as neural stem cells.
There is a mechanism suggested here by which restricting carbohydrate could help maintain weight loss, but weight loss has not been maintained in most of the many millions who have tried low-carb diets.
In a press release, the Château of Versailles states that the building has not been maintained or heated in six years and is in danger of being irreparably ruined without prompt attention.
"But it hasn't been maintained in years".
"The pier has been neglected and hasn't been maintained," Mr. Costello added.
The 2008 youth turnout bump was basically candidate driven and hasn't been maintained.
High standards had not been maintained in this regard by the representative and a breach of the code was ruled".
Trams have not been maintained since the 1990s despite the availability of tens of kilometres of infrastructure.
