Yes! Depending on your annual pass type, you can visit Brick Days with your annual pass. Please note, restrictions dates still apply. Please check your validity dates of your annual pass below:
https://www.legoland.co.uk/tickets-passes/annual-passes/legoland-annual-passes/
If there is a specific date that is restricted due to your pass type, you can purchase an exclusion date ticket to go alongside your annual pass at the bottom of the page on the link above.