Review: #21318 IDEAS Tree House

Why are tree houses so appealing—maybe because they are a place where your imagination can run free? Kevin Feeser’s LEGO IDEAS submission earned 10,000 votes in just four months… Let’s see if the final version lives up to the hype!

As LEGO continues to move forward with their ever-popular IDEAS line, the largest set yet hit the shelves this summer with Kevin Feeser’s Tree House. With a whopping 3036 pieces, it surpasses the 1969 piece #21309 NASA Apollo Saturn V—this set will stand tall in your LEGO collection! With two foliage color options, a therapeutic build experience and LEGO’s pledge to make their pieces more environmentally sustainable, this set is already an immediate hit in stores. This review explores the finer details in this set as we discover whether this makes the cut to grace your LEGO display.

#21318 IDEAS Tree House

#21318 IDEAS Tree House. Photo: LEGO.

About the set

#21318 Tree House comes with a whopping 3036 pieces, the largest of any LEGO IDEAS set and amongst the bigger LEGO sets available on the market. As with other large LEGO IDEAS sets like #21309 IDEAS NASA Apollo Saturn V and #21310 IDEAS Old Fishing Store, the price-per-piece ratio for this set is phenomenal. Priced at $199.99 (£179.99) this comes to $0.06 per piece. This price per piece places it at a much better rate than the average $0.10 per piece for most LEGO sets. It weighs in at 8.37lbs (3.8kg) and measures at 14 inches (35cm) tall, 10 inches (25 cm) wide, and 9 inches (23cm) deep. From a sprawling forest floor and picnic area to a beautifully crafted tree all the way to creatively built houses, this build is packed with details.

LEGO Plants From Plants

In 2018 LEGO took its first step to produce more environmentally sustainable products. As their first trial, several elements including leaves, trees and bushes were made from a plant-based polyethylene plastic, a substance that is made using sustainably sourced sugarcane. This change is the first of many steps that LEGO will make towards their ambitious commitment to make all of their products using sustainable materials by 2030.

Kevin’s initial idea

Kevin Feeser's Tree house

Kevin Feeser’s Tree House. Photo: Kevin Feeser.

In Kevin’s words “The idea of the model emerged during an unusual weekend with friends in a Robinson Crusoe-style tree house”; the rest is history. Taking him approximately 300 hours to design, Kevin remodeled the project 6 times before ultimately coming to his creation. Working with the LEGO designer, they tweaked the original design and ultimately came to the design that you see on the shelves.

For fans of LEGO and those who wish to one day have their sets appear on the LEGO IDEAS platform and see success, Kevin has some advice:

  1. Be creative – check out what’s out there … and then do something entirely different
  2. Be inspired – put together a portfolio of real things (photos, drawings, etc)
  3. Be prepared – source the right elements, visit the LEGO Pick-a-Brick website, etc

First impressions

In a word, Wow! I’ve been fortunate enough to review some fantastic sets over the last year, but each large set raises the bar even further. From the box to the instructions to the set itself, each has been designed with care to give builders of all ages the most satisfaction as possible. As this is a large set it should come to no surprise that the box itself is large too. Weighing 8.37lbs (3.8kg) the box measures 22.8 inches wide (58cm) to 18.7 inches high (47.5cm) to 4.7 inches deep (12cm). A large and heavy box for a large set. This set comes with 19 numbered bags, however bags 1 and 13 have two bags for each, with an additional 5 bags existing for each color of leaves. Unsurprisingly a large number of bags.

#21318 IDEAS Tree house box and packaging

#21318 IDEAS Tree House box and packaging.

#21318 IDEAS Tree house Instructions

#21318 IDEAS Tree House Instructions.

Build Process

With large sets comes a large number of steps and details. In order to make the build interesting and unique there are a variety of techniques employed when designing this set. To fully capture the aesthetics of the set while not spoiling everything, I will be breaking up the build into four parts. Each of which will explore design decisions, notable techniques and an overall description of that part of the set.

#21318 IDEAS Tree house

#21318 IDEAS Tree House.

The base

On one side of the base runs a narrow stream, breaking up the green with another color. To employ a rippling effect the designer opted to use two plates stacked upon each other. On the bottom are light blue plates, on top of which transparent plates are added. Initially I had wished that the designer used tiles rather than plates for the upper transparent layer, however the studs on the plate give off a flowing feel to the water, as if it is a rapidly flowing current.

#21318 IDEAS Tree house base stream

A shallow stream flows along the base of the tree house.

Aside from the tree there is a variety of foliage on the ground around the tree house. These include flowers, leaves and even mushrooms. Despite being immediately distinguishable I wish LEGO had used a 2×2 Dish inverted with a Mushroom Spots pattern printed on it rather than using a plain red part. This very simple addition could have enhanced this set further. This omission however does not detract from the overall quality. A picnic table can also be found at the base of the tree house. On this table sits a variety of objects, including my favorite on this level, a well-crafted candlestick holder. This picnic table has seats so the family can enjoy a meal while experiencing nature. When LEGO first introduced the new wand part with the Harry Potter line, many speculated the endless uses for this part. This set is one of a few sets in 2019 that have found new uses for this versatile part. Alongside a picnic table the inhabitants of the tree house also have a small fire pit to cook food at. This firepit uses three of said wands as a wood frame for a cooking pot to rest on.

#21318 IDEAS Tree house picnic

A picnic table is set ready for a meal for the minifigures to dine at.


When thinking about building a tree house one of the most important parts is the tree itself. Built with a technic frame, the tree in this set is the center structure that everything is built around. Using a lattice pattern, the interior of the tree is built sturdily and attached to the base through technic pins. The tree itself is built into an octagonal pattern, and each side is built independently. To make the build interesting and not repetitive each side of the tree is unique. Each side of the tree is built using a variety of tiles, plates and sloped pieces to give the tree a bark-like texture with varied color.

#21318 IDEAS Tree house tree

A strong, aged, and sturdy tree is great for supporting a tree house.

Aside from the build being varied, aesthetically the variety is pleasing to the eyes as well. With the houses placed on their appropriate branches the tree looks full of volume. This changes however when the houses are removed. Proportion wise the trunk is very thick but has very few branches building up to the canopy. This leaves all the branches coming out of a very narrow portion of the trunk near the top of the tree, something that anatomically looks odd. Luckily this is remedied through the use of the houses, which mask these incorrect proportions. Looking down from the canopy and towards the roots we see a similar issue. For a tree this size, there are very few roots sprawling at the base to offer support. It can be argued that all the roots are just underground, however with no noticeable elevation in the ground and an abrupt stop to the roots this can look off-putting. These small easily ignored flaws however are not enough to detract from the beauty that is the rest of the tree.

#21318 IDEAS Tree house bird

A bird lives in a small tree house of its own.

All of these details do not even begin to cover the beauty that is the tree itself. Comparing it to other trees that have been built by LEGO, despite having its flaws, I do think this is the largest and most accurate tree that has been built. The only way to fully appreciate the scale and detail placed into this trunk is to see it in person. Something that can be done at LEGO stores while this is still on the shelves and new.

Tree House

Despite all the details in the tree and the base, the magic in the design of this set lies in the houses. The houses themselves could make for a remarkable set on their own, so when combined with everything else this set has on offer, we really start to see something magical. In the tree houses we have two bedrooms and one bathroom. A perfect space for a family of four to live, with one bedroom being for the parents and one for the children. Outside of each house are balconies and walkways to allow the minifigures to travel between the houses. Care was taken to ensure that each house is accessible from another or the base.

#21318 IDEAS Treehouse picnic

From balconies to houses to bridges. The tree house has it all.

On the outside, most of the houses, with the exception of their balconies, are built the same. As a clear fan of octagons, the designer has opted to build each house in an octagonal shape. The walls of each house are built independently then are connected together at the end to make the shape come together. Despite being made of wood, the designer opted to choose a lighter shade of brown than the tree to help distinguish the house from the branches. This color in abundance stands out very well from the rest of the tree. To contrast even further the build itself has detachable roofs that come in an earth blue color. These, unlike the rest of the house, are rather repetitive as the core design of them are the same. Because of their similarities, the designers did opt to place a colored plate on the inside of each roof. When looking at the top of each house you can see that same color tile which tells you where each roof goes after removing them. This was a very small and neat addition that was not needed but helps enhance this set.

Parents’ bedroom

#21318 IDEAS Tree house parent's bedroom

The parent’s bedroom is filled with details. Can you find the hidden details.


Moving away from the bedroom we get to build our second house. Rather unique to LEGO sets is the bathroom. In this room there is a washbasin, a tub and shower along with a toilet and shelving space. Similar techniques for the shelves are employed from the other rooms but all other appliances are uniquely built. The washbasin and tub are nothing to write home about, as both are rather simple appliances anyway however the shower and toilet are both interestingly build. The toilet comes with everything, from toilet paper (oddly green), to a flusher to water in the toilet bowl. Unfortunately, because of how minifigures are designed they are unable to sit on this without half of their body leaning off the side of the toilet, an impractical position to be in. My favorite is the shower. With controls for the temperature and an adjustable showerhead, LEGO minifigures can easily fit in the shower and get clean. Littered on drawers and by the shower are soap and shampoo bottles to ensure they are extra clean. Since this bathroom is in a tree, your first reaction would be “how on earth does this room get plumbing”. This question was thought about by the designer. Looking at the back of this room we see a water tank, which can collect rain and sustainably provide water for all those who use the appliances in this room.

#21318 IDEAS Tree house bathroom

Running water is a luxury afforded to the inhabitants of this tree house.

Children’s bedroom

Last but not least we have the children’s bedroom. Similar to the parents’ bedroom this room is filled with small possessions on shelves or on the wall. The bed in this room however is different. Rather than building a single queen-sized bed we get to build a double decker bunk bed (not couch) that even Emmet from the LEGO movie would be proud of. The designer creatively used oars rather than bars to build the frame of this bed, giving it more character and making it look more unique. The shelves and drawers in this room employ the same upside-down building techniques in the first room. Letting us once again practice this new technique so we can use them in our own builds. Of the decorations we have three notable standout pieces in this room. The first is a rose in a glass dome. This decoration piece to me was very reminiscent of the rose in Disney’s Beauty and the Beast, something that looks very pretty. The next one, though small, uses a piece that is unique to this set. On the dresser is a jar with what looks like a dragonfly in it. This print is difficult to notice, especially when crammed in this room, but is a cool new piece to look at. The final thing I liked was the bedtime story. This book is tucked away beside the bed and is a cute little throwback to the days where we or our parents would read a bedtime story before going to sleep.

#21318 IDEAS Tree house children's bedroom

A bunk bed can fit two children comfortably.

Exterior details and walkways

The interior to each of the houses are super different, however on the exterior there are many similarities, some of which we’ve already discussed. There are balconies for each house, each of which has an interesting interactive piece of furniture. From a telescope, to a pulley system to help bring up supplies, there are many pieces that both your LEGO minifigures and your human self can play with. To help enhance the look and feel of the tree house cabins the designers opted to choose a variety of browns along with printed planks to ensure the rustic feel is brought across. By using these printed tiles, along with cylindrical pieces, plates and arches the tree house looks very handmade. Around the houses are the balconies and walkways we discussed. Despite looking like a safety hazard these are wide enough to fit a minifigure on each, allowing for a lot of poseability. For me, one of the most interesting yet simple pieces of decoration are the lanterns along the sides of the houses. These are built simply, but make use of the LEGO Marvel Black Panther minifigure head piece to add texture to the top of each of the lanterns. A big thumbs up in my eyes for creativity. But this comes to no surprise in this set.

#21318 IDEAS Tree house exterior

The exterior of each tree house is just as detailed as the interior.

Aside from the houses and the tree we get to spend some time building a rickety bridge and a wooden staircase. These two connect the houses together and the base to the upper level of the build. To achieve the range of motion desired for the bridge, the designer chose to build each rung independently and connect them between the houses using a ball and socket joint. This (as can be seen in the picture) creates a very natural flowing look to the walkway, almost giving off the impression that it wobbles as the figures walk across it. The stairs, despite looking complex, are actually rather simple. For the bulk of the stairs the designer opted to use a generic LEGO staircase piece, modifying it slightly to be in line with the other stairs they added. To supplement this and get a curved effect for both the top and the bottom pieces we build each level independently and connect them together using clips along a rod. This allows us to have flexibility with the range of motion. To secure it tightly each of the levels has an indent that the upper level slides into, fitting them together snugly. Just like the balcony we can see safety violations at play with this staircase however. There are railings for the majority of the staircase but once we get to the top this seems to taper off a little. Let’s hope the adventurous children who climb up these stairs watch their step.

#21318 IDEAS Tree house stairs

The entire tree house is connected through a series of staircases and bridges.

The seasons and foliage

One of the stand-out features of this set is the interchangeability of the leaves. Unsurprisingly as seen earlier when discussing the new plant-based parts just over 6% of the total pieces in this set are used just on the leaves alone. Coming in 4 different colors, this set gives the builder 4 different limb element pieces. 55 in bright green and yellowish orange and 35 in earth green and dark orange. With this variety of pieces, you are able to build your foliage for your tree to represent either the summer or fall (autumn) season. Both of which boast vibrant and easily recognizable colors. With some creativity and parts purchased on Bricklink, an online LEGO pieces store, or directly through LEGO you could even add the final two missing seasons to your collection. As a fan of browns, reds and orange the fall colors screamed out to me. But having built both now it is apparent that both colors are spectacular.

#21318 IDEAS Tree house foliage

A spare set of foliage allows you to change the color of your tree house whenever you want. Photo: LEGO.

Despite being amongst the prettiest parts of the build, this section in my opinion was the dullest. Despite minor variations in how the leaf appendages are connected, for the most part each branch is identical. Seeing how many branches are in this set you can immediately see how after a few branches this can get monotonous. The way the branches and foliage have been designed however requires quite a bit of building whenever you want to change the foliage color. Luckily LEGO is designed to be built so the designer put great thought into making this experience as varied as possible for each different time you modify the colors. Of the seasons, the fall colors provide a stark contrast with the forest floor, while the summer colors stand out very brightly against the trees and the tree house. Personally, I have decided to not just stick with one color, and instead will be modifying my tree house’s foliage colors to be in line with the seasons. Making this a rotating display piece that is always fresh and unique. Although this repetition being somewhat dull to me, to others this can be therapeutic. Along with the varied colors I do not ding this repetition too heavily against this set as there was not much the designer could do to vary this.


Despite being a large set, the tree house only contains four minifigures. That being said, these figures are perfect for this set, representing a family who are either on an adventurous vacation or live in the tree house. The figures included in this set are two parents; a mother and a father, and two children; a son and a daughter. None of the figures included in this set are exclusive, however some minifigures have only been included in five or fewer sets. Of all the figures only one has two faces, which at first seemed disappointing, but after admiring the detailed printing on the torsos we can see that the designers put their resources elsewhere.

#21318 IDEAS Tree house Minifigures

#21318 IDEAS Tree House Minifigures. Front and back view

Despite nice printing and nice minifigures I wish there was some exclusivity in designs for these figures. When looking at other minifigures in the IDEAS line, small or large we can see exclusivity. For a $200 set I think the minifigure selection is rather weak and feels like a selection of figures you would find in a smaller creator 3 in 1 or city set. Nonetheless, the figures are still nice to own when taken out of the context of this set.

Spare pieces

Large sets in general have many spare pieces but the number available in this set is astounding. Even when ignoring the fact that we receive two sets of foliage, one for each season, LEGO has provided spare pieces ranging from small 1 by 1 studs, all the way to larger pieces ike spare foliage and a paddle. Most surprising is the repeated spare pieces. It is uncommon in LEGO sets to receive 2 or more of the same pieces. This threw me off when building as I always had to double check to make sure I did not forget a piece as there is no consistency with when a duplicate spare piece is given. This large number of spare pieces is a great addition to any LEGO fans’ collection. With some rarer or new pieces being provided as spares.

Spare pieces, excluding spare foliage

Spare pieces, excluding spare foliage.

The new pieces

As is common with sets in 2019 there are a large number of new pieces either unique to 2019 or unique to this set. While building this set many of the pieces you use may end up being new pieces without you even realizing it. In total this set contains two pieces that are exclusive to this set and 44 pieces that are used in five or fewer sets at the time of this set’s release. With this being such a large number, we will be having a look at all of the pieces that are exclusive to this set or can only be found in two or fewer sets at the time of this set’s release. This set also sees the rerelease of what were collectible minifigure line exclusive accessories in the form of Jasmine’s bird from Disney 2 and the Cowboy’s hat from series 18 along with a myriad of other pieces.

Pieces unique to this set:

  1. 38639 Round Brick 1×1 No.18, in 42Transparent Light BlueTrans-Light Blue
  2. 29198, Flat Tile 1×1 Round No. 61 in 26Black

Pieces in two or fewer sets:

  1. 76382, Mini Upper Part No. 4354, in 5Brick YellowTan
  2. 60596, Frame 1x4x6, in 308Dark Brown
  3. 31493, Brick 1×2 With Cross Hole, in 308Dark Brown
  4. 43723, Left Plate 2×3 W/Angle, in 140Earth BlueDark Blue
  5. 43722, Right Plate 2×3 W/Angle, in 140Earth BlueDark Blue
  6. 3062, Round Brick 1×1 No. 18, in 141Earth GreenDark Green
  7. 76382, Mini Upper Part No. 4288, in 312Medium NougatMedium Dark Flesh
  8. 2465, Brick 1×16, in 192Reddish Brown
  9. 35381, Flat Tile 1×1 Round, in 192Reddish Brown
  10. 13565, Figure Head Clothing No. 8, in 138Sand YellowDark Tan
  11. 34090, Bottle No. 1, in 40Transparent Trans-Clear
  12. 48831, Bird No. 10, in 1White


From LEGO IDEAS to the LEGO shelves. #21318 Tree House is a wonderful set that explores nature and fittingly uses plant-based parts to enhance an already great set to become a staple of any LEGO fans’ collection.
The LEGO Group provided this set for the purposes of this review. The opinions in this article are strictly my own—providing sets for review does not guarantee a positive review. Photos in this article are by Koen Van Der Hoeven unless otherwise noted. Visit the About page for more info about our journalistic standards and affiliate programs.

15 Responses

  1. Bill says:

    I felt that the tree house was difficult to build. Not used to the vertical build. I thought the worst thing about the set was the instruction manual. Very difficult figuring out where pieces go. They were not outlined as other kits are.

  2. Quinn says:

    Hello! I unfortunately lost bags 13, 17, 18 and 19 🙁 — how would you suggest identifying the bricks in those bags so I can reorder? Any suggestions would be appreciated!

    • Tom Alphin says:

      There is no good way to do this – your best bet is to simply download the PDF building instructions and manually record all the parts you need for those bags.

    • Kati says:

      I have not opened these yet, if pictures help I’d be happy to send them.

  3. Jessica says:

    I am just starting to build this set. Bag 4 is where I am at. Setting the trunk is so hard and I barely managed putting the 4 sides up but now having issues with the 4 smaller sides. So far not enjoying it as much as the other sets I have.

    • Kati says:

      I thought this was just me, and have been scouring the internet and brick sites to get tips to get those sides on. I am really struggling (and I have built a lot of complicated/adults sets) and it’s taking the wind out of my sails… along with stopping my progress.

      • Serande says:

        This one for me required removing the axle holding the trunk external to the white technic upright anchor, removing the trunk entirely and fitting the diagonal sides with a view from above and below those small jutting saucepan pin connectors. Much easier to do, then reseat the tree on the white technic upright and replacing pin. (Had to remove two plates to get axle out.)

  4. sky says:

    Loooots of fails on injection points.

  5. Sonya says:

    This took my 12 yr old to build in 8 hours to a tee. He loved it

  6. Anonymous says:

    How long did it take you to build??

    • Koen Van Der Hoeven says:

      This set took me about 10 hours to build but time varies on how attentively you are trying to build

  7. margaret buck says:

    can not find tree house lego 21318 anywhere

  8. James says:

    When & where can I purchase this set?

    • Koen Van Der Hoeven says:

      Hey James,

      This set is actually already out. You can purchase it on the LEGO website or you can click on one of the links in this review which will take you to the shop directly! These are also available at your local LEGO store if you live close to one and want it right away.

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