Communications Director for The Royal Palace of Brussels, Francis Sobry, states "the building permit has been obtained in good and due form, with a request respecting French regulations."
"Even in protected areas, to build collective facilities of general interest, when the reason is related to security, the (building) regulation provides an exception, to get a waiver and that's what was done".
The royal couple's house is located on the Route du Ponant, near the Pointe du But, in the far north-west of the island, "in a natural area, like the entire hamlet", confirms The Royal Palace.
The renovations are near the central building where the royal family is housed. The construction of an annex to house “the security services" is planned, near the road, at the entrance to the 70-acre site. The article includes a picture with the caption "The 40 m2 annex is built on the edge of the road" showing construction at the entrance to the property. Notice the 'screen' mentioned by Somebody in her post #14.
https://www.ouest-france.fr/pays-de...nstruire-obtenu-en-bonne-et-due-forme-7140462