Skip to content

Back of the Box Builds

LEGO Alternate Builds!

SETS
- Adventurers
- Aquazone
- Belville
- BATMAN™
- BIONICLE
- Building Set with People
- Castle
- Duplo
- Fabuland
- Harry Potter
- Holiday and Event
- LEGOLAND
- Model Team
- Pirates
- Space
- Star Wars
- Technic
- Train
- Town
- Universal Building Set
- Western
- More Sets
- Misc
USEFUL LINKS
THIS IS AN INDEPENDENT SITE NOT AUTHORIZED OR SPONSORED BY THE LEGO GROUP

Alternate Builds Instructions Added Large Alt Build Large Builds Model Team Model Team Alternate Builds

5521 – Back A

January 29, 2026March 4, 2026 Master Builder 4129 Views

From: 5521: Sea Jet
Name: TBD ¹
Instructions: View PDF | Download .io File

Contributions

Name, PDF and .io file submitted on January 29, 2026 by: livi

← Space Skeletal Horse Concept
5581 – Back A →

You May Also Like

6396 – Back C

July 14, 2021July 14, 2021 Master Builder

6351 – Back D

July 14, 2021July 14, 2021 Master Builder

565 – Back D

July 11, 2024July 11, 2024 Master Builder

6642 – Back B

April 8, 2020April 8, 2020 Master Builder

6340 – Back D

November 20, 2023November 29, 2023 Master Builder

6360 – Back D

October 19, 2019October 25, 2021 Master Builder

EXPLORE MORE OFFICIAL SETS

Classic Space Classic Space Sets Official Sets Space Very Small Builds

6821: Shovel Buggy (Geological Inspection)

February 17, 2026February 17, 2026 Master Builder

Year Released: 1980BricklinkInstructions

Box Story Medium Builds Official Sets Time Cruisers Time Cruisers Sets

6497: Twisted Time Train

March 17, 2025March 17, 2025 Master Builder

Episode IV/V/VI Official Sets Small Builds Star Wars Star Wars Sets

7128: Speeder Bikes

July 14, 2021July 14, 2021 Master Builder

Extra Large Builds Model Team Model Team Sets Official Sets

5550: Custom Rally Van

February 9, 2026March 4, 2026 Master Builder

Bonus/Value Pack Alternate Builds Bonus/Value Pack Sets Bonus/Value Packs Medium Builds Official Sets Space Port Town Town Sets

6469: Spaceport Bonus Pack

March 3, 2025March 3, 2025 Master Builder

Harry Potter Harry Potter Sets Large Builds Official Sets Sorcerer's Stone

4708: Hogwarts Express

July 13, 2021August 8, 2024 Master Builder

Classic Town Fire Official Sets Town Town Sets Very Small Builds

6611: Fire Chief’s Car

February 20, 2024February 20, 2024 Master Builder

Airport Classic Town Official Sets Race Small Builds Super Model Town

Super Stunt Machine

March 8, 2025March 10, 2025 Master Builder

Large Builds Official Sets Technic Technic Sets

951: Bulldozer

December 17, 2025December 17, 2025 Master Builder

Divers Medium Builds Official Sets Town Town Sets

6558: Shark Cage Cove

December 29, 2021December 29, 2021 Master Builder

Classic Town Official Sets Police Small Builds Town Town Sets

1895: Sky Patrol

June 1, 2022June 1, 2022 Master Builder

Harry Potter Harry Potter Sets Official Sets Small Builds Sorcerer's Stone

4702: The Final Challenge

August 8, 2024August 8, 2024 Master Builder

Jørn Thomsen Official Sets Small Builds Spyrius Spyrius Sets

6835: Saucer Scout

November 9, 2019July 29, 2023 Master Builder

Classic Town Construction Medium Builds Official Sets Town Town Sets

6581: Dig N’ Dump

November 7, 2022November 7, 2022 Master Builder

Aquashark Aquazone Aquazone Sets Official Sets Very Small Builds

6135: Spy Shark

March 21, 2023March 21, 2023 Master Builder

Box Story Large Builds Ninja Ninja Alternate Builds Ninja Official Sets Official Sets

6088: Robber’s Retreat

January 24, 2022April 3, 2024 Master Builder

BOXES

INSTRUCTIONS

FAVORITES

MINIFIGS

About This Site

There were once pictures of additional LEGO® builds on the back of set boxes. Written on the boxes was typically something about the endless building possibilities, "Build any of these exciting models with this set!" There were no instructions for these alternate builds, until now.

Sets

Adventurers
Aquazone
BATMAN
Bionicle
Belville
Building Set with People
Castle
Duplo
Fabuland
Harry Potter
Holiday and Event
LEGOLAND
Model Team
Pirates
Space
Star Wars
Technic
Train
Town
Universal Building Set
Western
More Sets
Misc

Useful Links

Submit Instructions!
New Instructions
New Official Sets
New Alternate Builds
Minifigs
Very Small Builds (<35 pcs)
Small Builds (<100 pcs)
Medium Builds (<200 pcs)
Large Builds (<400 pcs)
Extra Large Builds (>400 pcs)
How BOTBB was Built

In Honor of 1526

The classic space set that never was.

Copyright © 2026 Back of the Box Builds. All rights reserved. LEGO® is a trademark of the LEGO Group of companies which does not sponsor, authorize, or endorse this site.