How to Build a LEGO Piggy Bank: Step-by-Step DIY Tutorial
Here is the short answer up front: a brick piggy bank needs no special parts at all. A few dozen basic bricks and roughly 30–40 minutes are enough to build a working little vault with your child — one that accepts coins, lets you take money out, and has a dust cover on top. For the body, a square structure with a 14x14 base and a height of 10 layers works well; the interior clearance is tall enough to hold both notes and coins, and the finished box is slightly larger than a can of cola, so it sits nicely on a desk. The full step-by-step tutorial follows.
Step 1: Gather the Parts and Tools
Do an inventory before you start building. Plan on mostly basic 2x4 and 2x2 bricks, roughly 120–150 pieces in total, plus 4 2x8 plates for the base. If you want your own color scheme, 3–4 different colors will look better than a single one. As for tools, you only need a brick separator to pry up misplaced bricks — nothing else. If you are short on parts, you can look up the parts list for a similar piggy bank on brickplan.cn and gather the pieces from that.
Step 2: Build the Base Plate and the Box Body
Start by laying one 14x14 layer of base, using 2x8 plates interlocked with each other and no gaps in between. Then begin stacking walls around the perimeter using a cross-bond pattern — offset each layer by half a brick so the seams never line up. This makes the walls much stronger and far less likely to fall apart. Keep stacking up to layer 10 to form a square box. Do not close off the top at layer 10; leave it open for the coin mechanism you will add later.
Step 3: Design the Coin Slot and the Withdrawal Door
The coin slot goes on the front face at layer 8. The method is simple: when you reach layer 8, leave a 1x4 gap in the middle, fill the sides with 1x2 bricks, and cap it with a 1x4 plate. That gives you a slot about 3.2 cm wide, wide enough for a coin or a folded banknote to drop in easily. The withdrawal door goes on the lower side of the box: fit a 2x4 door brick there first (you can substitute a hinge piece, or a plate with a loose fit). It stays closed in normal use and simply slides out when you need to get money out. The advantage of a bottom withdrawal door is that you never have to smash the box open.
Step 4: Add a Removable Dust Cover
The top of the piggy bank should be a removable lid, which keeps dust out and makes it easy to count the contents once the box is full. Build a lid slightly larger than the box opening from 2x8 plates, then use 1x1 round plates at the four corners as locating studs that clip onto the top rim of the body — it will not fall off easily, yet lifts off with no effort when you need it. You can also leave a small window in the lid so your child can see the savings piling up inside, which is a good incentive to keep going.
Step 5: Build Time and Parent-Child Play
With two people working together, the build takes about 30–40 minutes. The child handles stacking the walls and decorating, while the parent checks the dimensions and lines up the coin slot. Once it is finished, agree on a small daily task with your child — "one coin a day." That adds up to 7 coins in a week and about 30 in a month; a calendar checklist makes it work even better. Throughout the build, your child repeatedly practices counting bricks, aligning them, and taking pieces apart and putting them back together, which is good training for spatial awareness and patience.
FAQ
Q: How exactly do you make a brick piggy bank? A: Build a 14x14 base first, then stack cross-bonded walls up to layer 10. Leave a 1x4 gap at layer 8 on the front for the coin slot, fit a sliding door at the bottom as the withdrawal opening, and finish with a removable lid to keep dust out. The whole thing takes 30–40 minutes.
Q: How wide should the coin slot be so coins do not get stuck? A: Make the slot at least 1x4 wide (about 3.2 cm) and leave 2 layers of height open. That way coins and folded banknotes both drop in smoothly without catching on the edge, and it is safer for small hands to use.
Q: How do you get the money out? A: Fit a removable 2x4 door brick on the lower side of the box as the withdrawal opening. It stays closed the rest of the time, and once the bank is full you slide the door out and tip the contents out. No smashing required, so the bank can be reused again and again.
Q: Will it fall apart while we are building it? A: As long as every layer uses the cross-bond method with offset seams and you reinforce the four corners with 1x1 round plates, the body is very sturdy. In normal use you only drop coins through the slot and never shake it hard, so it will hold together for a year of everyday use.
Q: What age can complete this independently? A: Children aged 5 and up can join in with stacking walls and decorating under adult supervision, and by 7 most can complete the main structure on their own. The whole build uses only basic bricks pushed together, with no small-parts risk, which makes it a good entry-level parent-child project.