Roof of PM’s office is original 16th-century flat-plack

The roof of the Torentje, or Little Tower, at the Binnenhof in The Hague was built in 1547 as a construction kit and has been largely untouched since, broadcaster NOS reported on Thursday.

The research on the eight-metre-high spire above the office of the prime minister was carried out by the Rijksvastgoedbedrijf, the government’s property agency, during the ongoing renovation of the complex.

The ceiling was opened last year to check the area for asbestos, which was found, revealing the oak roof structure behind it.

The wooden construction has needed practically no repair work in 478 years.
An inspection revealed that the beams were sawn by hand, typical in the days before the widespread use of sawmills. The wood came from an oak tree felled in southern Sweden around 1546.

Roman numerals are also chiselled into the beams, indicating that the roof was built in a workshop, taken apart and transported to the building site. The numerals show which parts belong together, like the instructions for a piece of Ikea furniture.

The tower itself is older: the earliest records date from 1497, and Emperor Charles V had it completely rebuilt in 1547, when the spire was added.

The renovation of the Binnenhof began in 2021. The work was initially expected to take five years and cost €475 million, but the bill has since risen to at least €2.7 billion and completion has been postponed until 2031.

Earlier this year, archaeologists found an early 14th-century city gate at the site.