The Scottish firm who built the Big Brother 3 house say it's the most difficult job they've ever done.
They say the hardest thing was creating such a big open plan area inside the house.
Caithness builders Woodco have been working seven days a week since January to get the project completed in time for the first episode.
The show's producers have decided it's new base at Elstree Studios will be permanent following the first two temporary houses in East London.
The enormous compound includes a 25-square metre pool, a garden, vegetable patch and chicken coop.