For the first time, the doors of Old Parliament House were swung open for the ACT Superbooth for local and interstate voters taking part in ''Australia Decides 2013''.

''The Australian Electoral Commission really underestimated how popular this was going to be,'' museum director Darryl Karp said.

''We were told to expect 600 people. There were 600 people lining the steps by 9am.''

By 2pm, more than 4000 voters had cast their vote at the historic site. Many waited in line for more than an hour to do so.

Outside, the democracy sausages were sizzled by the Lake Tuggeranong Sea Scouts.

The lines for food were also constant but, thankfully, there were more manners on display than that fateful day in 1975 when prime minister Gough Whitlam was toppled.

Less ''We want Gough!'', more ''I'm gluten intolerant, so hold the bread thanks.''

Group leader Michelle Taylor was overwhelmed by the crowds who had devoured more than 900 snags before 2pm.

''We've had to call in reinforcements and leave our station at Melrose with less staff. We've also run out of bread several times but rather than complain people have just been waiting patiently in line while we run to the supermarket,'' she said.

The group, which is fund-raising to purchase a $1000 Rotary Shelter Box - an emergency housing kit for people affected by natural disasters in developing countries - had by 2pm nearly raised enough money to purchase two kits.

The only commotion on the day was the arrival of two shiny BMWs.

''Is that the Prime Minister?'' a small child was overheard asking his dad before a bride and groom emerged to have their names ticked off the electoral role before their reception.

The bride declined the offer of an ''I Voted At Old Parliament House'' badge which staff had been making non stop since 9am to keep up with demand.

Smartphones and books were the most popular companions for voters waiting in line. As was hydration.

''Here, have some water,'' a museum staff member said while handing out free bottles of water.

''Just be careful, it's a heritage floor.''

Once the polls closed, Ms Carp said more than 6000 people had flocked to the Superbooth to cast their vote under the watchful (bronzed) eye of King George V.

Many other polling booths around Canberra experienced a slight dip in voter numbers.

Luke Grattan, an Australian Electoral Commission officer in charge at the Maribyrnong Preschool booth, said: ''Whether it was prepolling or the novelty of Old Parliament House, our numbers were down on previous years.''

Over at Kaleen Primary School, things were decidedly more upbeat with the P&C selling more than 600 sausages and hundreds of slushies.

Downer Community Centre was the place all diabetics should have avoided. Cupcake-wielding Guides did a roaring trade, charming the throng of voters and volunteers who were in line from 8am.

AEC officer Chris Olsen was impressed with the goodies on offer. ''Like many of the 1200 or so locals who voted here, I couldn't resist the sausage sizzle or the politically themed cakes. I think I ended up eating seven cupcakes all up.''