The ACT's 12 new politicians are undertaking "pollie preschool" which will include a mock sitting day where they will present and debate bills.

The course, made up of three half-days, aims to prepare new MLAs for their new roles in the ACT Legislative Assembly while avoiding "information overload".

Assembly clerk Tom Duncan, who runs the training program, told 666 ABC Canberra all the new MLAs arrived for their first session on time and excited to learn.

"It's like any new job, you need to be aware of your surroundings... IT arrangements, security arrangements for the building, a little bit about the standing orders and the code of conduct," he said.

He said it would be too much to ask for the new MLAs' first day on the job to be an active sitting day.

"There are over 280 standing orders, so to impart each and every one of those is a big ask," Mr Duncan said.

"What we will do in a few weeks' time is have a mock sitting — we'll get them in the chamber and we'll run through a typical sitting day.

"We'll get them to move a motion, to present a bill, to debate a bill, to ask a question without notice.

"When we do come back they'll be familiar with the environment of the chamber and the standing orders and how they operate."

But he said there was likely to be some special consideration given to new members at the beginning of the next parliamentary term.

"Everyone has been there, when you're newly elected, and they know the pressures in terms of learning those 280 standing orders, so there is a degree of leniency," he said.

"But there's also lots of people to give advice to those members."

Assembly undergoes renovation to accommodate expansion

The expanded 25-member Assembly has also meant additional chairs have had to be added to the chamber.

A new central table will host the leaders of the major parties, similar to the set up in the federal parliament.

"In parliamentary terms it used to be 'two sword-lengths away' between the opposition and the government," Mr Duncan said.

"It's actually 190 centimetres, which is just a little bit shorter than the Federal Parliament, but it's actually wider than the Senate."