BUILDING a 18,000 piece Princess Leia Lego portrait takes skill and about 120 hours but it's just one of 70 exhibitions at the 2013 Brick Expo.
Organiser Stephen Calder said 12,000 people would attend the Lego lovers convention in Woden over the weekend.
Timed ticketing eased some of the crush on Saturday but the line for each session still snaked down Matilda Street, and it wasn't exclusively made up of children.
Gungahlin resident Fiona Judge's exhibition is targetted more at the grown-ups with an alarm clock, cake moulds, salt and pepper shakers and egg timer all made from Lego or by the company.
"My favourite has to be the bottle opener and corkscrew," Ms Judge said.
"It's so not Lego or what the company is about."
More than 2 million Lego bricks make up the exhibitions. Among the bigger drawcards are a two-metre tall christmas tree, a 20 metre long train and monorail track along with a blue life-size TARDIS made of 35,000 bricks.
Mr Calder said the event was growing with more interstate visitors than previous years.
"Last year we had 10,000 [visitors] so it's grown...and we've sold out of children's t-shirts already- we sold out in the morning," he said.
"I think it's the simplicity of the product that can be used in complicated ways...you don't need to read a rule book or be taught how to use them."
Lauren Baker along with her brother Nathan made the trip from Orange to the ACT with their parents especially for the expo.
The complicated designs impressed the six-year-old girl who loves to play with the plastic pieces and is keen to add to her collection.
"I have all the friends Lego," she said.
Tickets for Sunday's session of the 2013 Brick Expo have sold out.