Block sets that work well with Unit Blocks

Stick to a system - that's what I always say! But how do you do that when you'd like to add some variety to your block play?

Here's a list of block play products that we have in our home which are unit block aligned . All of these products are tried and tested by my family so you can bring in some variety but keep the system as mathematical as possible!

I have discount codes for these products - SAMI10 works at Guidecraft and SAMI15 works at Plan Toys!

Guidecraft unit block marble run - This is the only marble run set I recommend. Forget all the stand alone marble runs, don't buy the magnetic tile ball run sets, and get this. It's completely unit block aligned which means that you can use your already existing unit blocks to build with it. My kids have had this set (just 1 set is enough) since they were 3 and 5 and have been able to build with it indepenently from the beginning. Now they're nearly 6 and 8.5 and they're still finding awesome ways to play with it. Highly recommend.

Architecture unit blocks - this set is totally unit aligned but has some fun pieces that are very unique. It's a perfect for kids who like castles, towers, or other fancy buildings and are looking to add some more detail to their builds.

Plan toys castle blocks - these sets are unit block aligned! Isn't that fun? While the offerings here are a little bit more limited than the architecture blocks above, this set in particular has some really unique pieces that my kids adore.

Rainbow blocks, mirror blocks, and sensory blocks - these blocks are all Guidecraft classics and to be totally transparent they are not 100% perfectly unit aligned. They are the correct height and width for unit block play, but the depth is slightly off (I've been working with Guidecraft to correct some of these little inaccuracies but we haven't gotten to these ones yet) The good news is that the depth being off doesn't really effect play unless your kids are stacking them face to face... which with a window block is rare so I still recommend them. My kids love these for adding color and texture to unit block play!

Arches & tunnels - another unit block aligned treasure - these are the width of a unit block so they work perfectly within the system. You can also check out these newer discovery arches and stackers which also happen to be aligned with unit block width and are a really beautiful way to add color to block play!

In the new year Guidecraft's acrylic unit block line will be released. This is a product I have been working with GC directly to develop! We tried really hard to get them ready for this holiday season but ultimately perfecting the product felt more important than meeting that holiday deadline. In early 2026 you'll be able to add acrylic unit blocks, gem unit blocks, and wooden/acrylic window blocks that are all perfectly unit aligned to your collection! So if you're holiday shopping maybe consider a Guidecraft gift card along with this photo for your unit block lover!

Keeping your block play materials mathematically aligned has lots of benefits to your child's learning through play and also supports independent play by removing tricky points of frustration in their work. I highly recommend it.

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