Duncan Titmarsh is the UK's only certified Lego builder. He has a giant factory with over 35 million bricks and 24 builders working full-time. They complete an average of 600-700 projects per year.
Prices for the models range from a few thousand to tens of thousands of pounds.
He began building Lego models a decade ago in his garden shed, started a small part-time business, and then got certified by Lego in 2010.
His biggest one to date is a Lego Tower Bridge for Land Rover. It took 5.8 million bricks, 25 people, and 6 months to build. It weighed 5.5 tons, was 40m long, and 40m tall.