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LEGO Missing Piece Checker

Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece and leave with the element ID LEGO asks for, or a link to buy the part.

LOM Building B

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4000015 LOM Building B

215 pieces in 63 part and color combinations.

Before you call it missing

Builders who report a missing piece often find it in one of these places. Tick each one off as you look.

Look-alike colors in this set

These parts appear in this set in two colors that are easy to confuse. If you are one short in one color, check whether it went in where the other color belongs. Each color has its own element ID in the parts list at the back of the instructions.

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Piece checklist

Light Bluish Gray 60 pieces

  • Brick 1 x 2 Light Bluish Gray Part 3004 Element 4211388 ×2
  • Brick 1 x 4 Light Bluish Gray Part 3010 Element 4211394 ×3
  • Brick Special 1 x 2 with 2 Studs on 1 Side Light Bluish Gray Part 11211 Element 6015344 ×1
  • Brick Special 1 x 4 with 4 Studs on One Side Light Bluish Gray Part 30414 Element 4211636 ×2
  • Plate 1 x 1 Light Bluish Gray Part 3024 Element 4211399 ×10
  • Plate 1 x 2 Light Bluish Gray Part 3023 Element 4211398 or 3023194 ×9
  • Plate 1 x 3 Light Bluish Gray Part 3623 Element 4211429 or 3623194 ×3
  • Plate 2 x 4 Light Bluish Gray Part 3020 Element 4211395 ×5
  • Plate 4 x 4 Light Bluish Gray Part 3031 Element 4243797 or 4211403 ×2
  • Plate Special 1 x 1 with Clip Light, Bar Hole [Thick Ring] Light Bluish Gray Part 4081b Element 6281998 or 4632575 ×1
  • Tile 1 x 1 with Groove Light Bluish Gray Part 3070b Element 4211415 ×7
  • Tile 1 x 2 with Groove Light Bluish Gray Part 3069b Element 4211414 ×12
  • Tile 1 x 4 with Groove Light Bluish Gray Part 2431 Element 4211356 or 2431194 ×2
  • Tile 1 x 6 with Groove Light Bluish Gray Part 6636 Element 4211549 ×1

Dark Bluish Gray 43 pieces

  • Brick 1 x 1 Dark Bluish Gray Part 3005 Element 4211098 ×3
  • Brick 1 x 6 Dark Bluish Gray Part 3009 Element 4211100 ×1
  • Brick 2 x 4 Dark Bluish Gray Part 3001 Element 4211085 ×5
  • Plate 1 x 1 Dark Bluish Gray Part 3024 Element 4210719 ×1
  • Plate 1 x 2 Dark Bluish Gray Part 3023 Element 4211063 ×4
  • Plate 1 x 4 Dark Bluish Gray Part 3710 Element 4211001 ×2
  • Plate Special 1 x 2 with 1 Stud with Groove and Inside Stud Holder (Jumper) Dark Bluish Gray Part 15573 Element 6092572 ×1
  • Plate Special 1 x 2 with Door Rail Dark Bluish Gray Part 32028 Element 4543086 or 4541289 ×3
  • Tile 1 x 1 with Groove Dark Bluish Gray Part 3070b Element 4210848 Also in Black ×8
  • Tile 1 x 2 with Groove Dark Bluish Gray Part 3069b Element 4211052 ×3
  • Tile 1 x 4 with Groove Dark Bluish Gray Part 2431 Element 4211053 ×2
  • Tile 1 x 6 with Groove Dark Bluish Gray Part 6636 Element 4210651 ×2
  • Tile 2 x 2 with Groove Dark Bluish Gray Part 3068b Element 4211055 ×4
  • Tile Special 1 x 2 Grille with Bottom Groove Dark Bluish Gray Part 2412b Element 4210631 ×4

Green 24 pieces

  • Cone 1 x 1 [Top Groove] Green Part 59900 Element 4529239 ×5
  • Plate 1 x 1 Green Part 3024 Element 302428 ×4
  • Plate 1 x 2 Green Part 3023 Element 302328 ×5
  • Plate 1 x 4 Green Part 3710 Element 371028 ×6
  • Plate 2 x 3 Green Part 3021 Element 302128 ×1
  • Tile 1 x 1 with Groove Green Part 3070b Element 4558593 or 4238528 ×2
  • Tile 1 x 4 with Groove Green Part 2431 Element 243128 ×1

Trans-Clear 19 pieces

  • Plate 1 x 1 Trans-Clear Part 3024 Element 6513962 or 6252041 ×7
  • Plate 1 x 2 Trans-Clear Part 3023 Element 6514001 or 6240204 Also in White ×12

Black 17 pieces

  • Plate 1 x 3 Black Part 3623 Element 362326 ×1
  • Plate 6 x 12 Black Part 3028 Element 302826 ×4
  • Tile 1 x 1 with Groove Black Part 3070b Element 307026 Also in Dark Bluish Gray ×4
  • Tile 1 x 8 with 'LOM Building B' Print Black Part 4162pr0038 Element 6103359 ×1
  • Tile 1 x 8 with Groove Black Part 4162 Element 416226 ×7

White 17 pieces

  • Brick Special 1 x 1 with Stud on 1 Side White Part 87087 Element 6550190 or 4558952 ×8
  • Plate 1 x 2 White Part 3023 Element 6552100 or 6548261 Also in Trans-Clear ×2
  • Plate 1 x 4 White Part 3710 Element 6552108 or 6548266 ×5
  • Plate Special 1 x 2 with 1 Stud with Groove and Inside Stud Holder (Jumper) White Part 15573 Element 6550152 or 6051511 ×1
  • Tile 1 x 1 with Groove White Part 3070b Element 6550138 or 307001 ×1

Red 11 pieces

  • Brick Sloped 30° 1 x 1 x 2/3 (Cheese Slope) Red Part 54200 Element 5074621 or 4504379 ×1
  • Plate 1 x 1 Red Part 3024 Element 302421 ×1
  • Plate 2 x 6 Red Part 3795 Element 379521 ×3
  • Plate Round 1 x 1 with Solid Stud Red Part 6141 Element 614121 ×2
  • Plate Special 1 x 2 with Door Rail Red Part 32028 Element 4612575 or 4239063 ×1
  • Tile 1 x 1 with Groove Red Part 3070b Element 307021 ×2
  • Tile Special 1 x 2 Grille with Bottom Groove Red Part 2412b Element 241221 ×1

Reddish Brown 10 pieces

  • Plate 2 x 4 Reddish Brown Part 3020 Element 4211186 ×3
  • Plate Round 1 x 1 with Solid Stud Reddish Brown Part 6141 Element 4216581 ×7

Blue 5 pieces

  • Plate 1 x 2 Blue Part 3023 Element 302323 ×5

Bright Green 3 pieces

  • Plant, Flower, Plate Round 1 x 1 with 4 Petals Bright Green Part 33291 Element 6170300 or 4619599 ×3

Tan 2 pieces

  • Brick 2 x 2 Corner Tan Part 2357 Element 4124455 or 4112541 ×2

Dark Green 1 piece

  • Tile 2 x 2 with Groove Dark Green Part 3068b Element 6618078 or 4528778 ×1

Dark Red 1 piece

  • Tile 1 x 2 with Groove Dark Red Part 3069b Element 4539090 or 4529548 ×1

Trans-Light Blue 1 piece

  • Plate 1 x 1 Trans-Light Blue Part 3024 Element 6513964 or 6252043 ×1

Yellow 1 piece

  • Tile 1 x 3 Yellow Part 63864 Element 4558172 ×1

Tick each piece as you find it, or mark it missing.

When a piece really is missing

Ask LEGO

LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for the set number and each piece's element ID, the number printed beside the piece in the parts list at the back of the instructions. This checker lists both.

Request a replacement from LEGO

Buy the piece

Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from older or second-hand sets.

Keep a record

Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.

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