Staff at the two offices have also been instructed to encourage clients to access WINZ online services instead of going to see their case managers.
Rounthwaite said as well as improving efficiency, fewer face-to-face visits was good for security.
WINZ was also focusing on how best to use security guards, and on training staff in inter-personal and de-escalation techniques.
The organisation would carry out an evaluation of the new-look sites, then assess whether they should be introduced at more offices.
Public Services Association national secretary Glenn Barclay welcomed the changes, but said he would still like to see additional resources for security guards. "The MSD and WINZ are trying to get this right. They're taking it seriously and we appreciate that, but we still have some reservations," he said.
"Our members are saying it's important to feel secure at work. They would like to see things beefed up, particularly at the point of entry."
Russell John Tully is awaiting trial for the murders of Work and Income front counter workers Peggy Turuhira Noble, 67, and Susan Leigh Cleveland, 55, on September 1, 2014.
He is also accused of attempting to murder two other staff members - Lindy Louise Curtis, who was shot in the leg and badly injured, and Kim Elizabeth Adams.
The MSD has also been charged for allegedly failing to take all practicable steps to ensure the safety of its employees while at work. The MSD has pleaded not guilty to the charge.