Named in Welsh ‘Y Bwthyn Bach’, or The Little Cottage, the small estate was gifted to the then Princess in March 1932.
At 22 feet wide and 15 feet high, it was built to two-fifths scale and contains a living room, kitchen, bedroom and bathroom on the upper floor.
It has electric lighting and running water as well as cutlery, utensils and furniture.
A video of the straw-thatched house from the Royal Collection Trust shows clips and pictures of young Elizabeth and her sister, Margaret, playing around the house, as well as the cute interior of the building.