It sounds as if your Order of Protection has a full stay away provision. If so, I would immediately take it to the landlord and give it to the landlord stating that they would be breaking a Court Order by permitting him to move into the complex. You also could violate your Husband in the Court for breaking the Court Order. This is a very serious matter as it is alarming that he choosing to move into your complex of all places. You should not wait and seek legal advice immediately.
File an order to show cause in Family Court so s judge can decide whether to allow it.
I am a former federal and State prosecutor and now handle criminal defense and personal injury/civil rights cases. Feel free to check out my web site and contact me at (212) 577-9797 or via email at Eric@RothsteinLawNY.com. I was named to the Super Lawyers list as one of the top attorneys in New York for 2012. No more than 5 percent of the lawyers in the state are selected by Super Lawyers. The above answer is for informational purposes only and not meant as legal advice.