The phrase "add a new condition" is correct and usable in written English.
You can use it when discussing modifications or updates to rules, requirements, or criteria in various contexts, such as programming, project management, or policy-making.
Example: "To improve the system's functionality, we need to add a new condition for user access."
Alternatives: "introduce a new requirement" or "implement an additional criterion."
A government "white paper", published in January, added a new condition to the existing ones which, in Chinese eyes, justify military action: Taiwanese foot-dragging about reunification.
On Sunday, Mr. Assad added a new condition, demanding written guarantees that rebel forces would lay down their arms before his forces would withdraw.
Then he added a new condition, specifying that Mr. Chen's ruling Democratic Progressive Party must first rewrite the party's constitution to strip out endorsements of what the party refers to as the island's independent, sovereign status.
And the judge added a new condition (with another expense) to keep him from trying to obstruct justice: Mr. Madoff will no longer be able to try to transfer assets because all of his valuables will be taken by a security firm and locked in a vault; the items that remain portable and in his apartment will be monitored by another security firm, which is supposed to take an inventory every two weeks.
The report on Karzai's meeting with Rice added a new condition not mentioned in the White House statement: that the U.S. release Afghan prisoners from the detention center for terror suspects at Guantanamo Bay, Cuba.
The engineering teams' findings, which officials from the Defense Department and other agencies would discuss only on the condition of anonymity, add a new layer to disputes within the intelligence community about the trailers found by allied forces in Iraq in April and May.
A new clinical condition makes it necessary to add a new antimicrobial (different from those used in the study) with activity against MRSA.
