Building large structures with Lego requires careful planning and a massive number of building blocks. You can estimate the time commitment and material cost by looking at kits and existing sculptures. For example, the Imperial Shuttle Star Wars kit contains 2,503 pieces and costs over £162. For slightly less, the Tower Bridge kit has 4,287 bricks which complete a 3-foot long model. And for triple the price you can buy the world record 5,922-piece Taj Mahal set. Professional sculptures are larger still. The miniature New York skyline displayed at Legoland California features more than two million bricks. Before beginning to build your figurine consider fund raising to support the project: look for art grants, offer to give the completed sculpture to a school or construct the figure as part of a toy drive.

Draw a technical sketch of the sculpture that shows the scale and type of pieces to use.

Estimate the volume of the sculpture in single-block Lego units using the height, width and depth. For example, a head that is 50 bricks high, 20 blocks wide and 20 blocks deep has a volume of 20,000 Lego blocks; this piece can be built as a solid shape or as a hollow head. Calculate the volume of the hollow head by subtracting two units from each dimension and recalculating the volume. This volume represents the number of bricks in the interior of the head, excluding a two-brick thick shell. Subtract the new volume from the first to find the number of bricks necessary for a hollow head. For example, the product of 48, 18 and 18 is 15,552, and the difference between 20,000 and 15,552 is 4,448, so 4,448 single bricks are needed to make a hollow head.

Determine whether you want to use single blocks, long blocks or a combination. Estimate the quantity of bricks needed. For example, instead of 4,448 single bricks, you could use 2,224 doubles or just under 1,500 triple-peg bricks.

Choose a colour scheme. Save money and time sorting pieces by building the structure out of a random assortment of colours. Or use recognisable colour patterns to make a statement; for example, red and white to indicate a nurse or doctor.

Create a base out of flat pieces or use a commercial base. Plan ahead; if the structure will be large built it on a pallet so that it can be lifted and moved.

Build the structure. Stack bricks, staggering the order such that the seams of the previous layer are spanned by new bricks similar to the zigzag of a brick wall. If blocks are misplaced use a Lego brick remover to take them off, this tool prevents stress that weakens and discolours the walls of the bricks.

Strengthen your structure by coating the interior of hollow structures with plaster of Paris or liquid plastic.