Eddie Heath, from Dilhorne in Staffordshire, built the Buckingham Palace replica from a thousand wooden pallets donated by local companies.
In the past, he's built models of Big Ben, the Tower of London and the White House, but will now hang up his hammer.
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They will be joined by Duke Dumont and Disciples at this year's festival in Staffordshire.
There is no evidence the Westminster attacker Khalid Masood was associated with so-called Islamic State or al Qaeda, the Met Police said.
A cloudier start, but turning dry, sunny and warm.