A company called Apis Cor has 3D printed a (tiny) house in 24 hours for $10,000, which comes out to about $275/m2.
Reconstructing Buckingham Palace at 77,000 m2 this way would cost only about $21 million. According to a 2010 estimate in The Guardian: "you could build a new energy-efficient replica of the palace for a knock-down £320m", which translates to $552 million.
So: 3D printing the palace would save over a HALF BILLION DOLLARS! Muahahaha (pinkies up!).
Video of the building process.
(Score: 2) by Immerman on Tuesday April 25 2017, @01:32PM
Except the printed home is well insulated, including the windows and doors, fairly sound-proof, far more solid, and it sounds like that $10k might include the TV, counters, etc, etc, etc, inside as well.
There's also no inherent impediment for "pre-stamped engineering drawings" with printed construction - easy enough to get a selection of different popular designs pre-stamped to select among, and just squirt out the one you want on-site. Custom designs would obviously more expensive by the cost of engineering and certification, but there's potentially room for the structural components to be pre-stamped, with more cosmetic customizations (internal unloaded walls, counters, etc.) to be added in without needing approval.