The evacuation was part of a ‘business continuity drill’ to simulate what would happen in a serious emergency.
Although the county council has held fire drills in the past this was the first its kind to test how it would operate and people would react if it was a ‘major disaster’.
County council health and safety fire officer Gordon Richardson said the evacuation had been a success and the entire drill took just over an hour-and-a-quarter.
He said: “This is the first time it’s ever been done. The fire brigade were invited to give it some authenticity and we have obviously kept it a secret from staff. There will be one or two grumbles but the staff have been excellent.”
Almost 1,000 staff were evacuated to a spot near the Odeon cinema while Walton Street was closed off.
Mr Richardson (pictured left) added: “Staff have kept very calm and we have to tried to keep in contact with them.
“We have tried to reduce the effect of doing this on the council, meetings and parents who need to come in for meetings.”
Bucks Fire and Rescue also took the opportunity to test out its high rise building rescue abilities.
Station manager and commander Gary Taylor said: “We acted as if there was a fire on the seventh floor with one person unaccounted for. Within 25 minutes of arrival we were ready to carry out rescue.”
Mr Taylor said that while 25 minutes sounds quite lengthy it is actually a good time considering how long it takes to set up and carry their equipment to the floor.
He added: “It was a good opportunity for us to test it and it went really well and achieved its objective.”
But Brian Horridge, who was evacuated from the county records office on the corner of Walton Street, was unhappy about the disruption the evacuation caused.
He said: “This in the middle of the day is a waste of public money.
“They could just do it at the weekend not mid-week. It’s an abysmal waste of time and money.”