The activation, created with agency PrettyGreen, is part of the brand's #BuildToGive campaign and kicks off this weekend (18 November) at Centre: MK in Milton Keynes.
Over the rest of November and throughout December, Lego is hosting a number of #BuildToGive events across the UK. There will be two further shopping centre tours in Glasgow and Hull and events staged in dedicated Lego stores at various locations UK-wide, including Westfield London and Stratford City, Bluewater, Arndale Shopping Centre and Intu Watford.
Each event will have "Santa’s helpers" on hand to help participants create their decoration. Certified professional builder Duncan Titmarsh will also be on hand at the shopping centre tours, on Saturday dates, to share expert Lego building tips.
Once poeple's builds are complete, they will be displayed on a Christmas tree. Up to 20,000 Lego gifts nationwide have been pledged by the company, which is working in partnership with children’s charity Fairy Bricks.