Construction of Hôtel La Marina, Ouidah

The context

Hôtel La Marina Ouidah is an oceanfront hospitality project delivered by Gregori International. The site combined unusual constraints: marine wind exposure for drone flights, earthworks management in sandy ground, landscape and contractual green-space tracking. The project lead wanted standardised photogrammetric monitoring across all phases — from earthworks to finishes — comparable to the GMK Stadium for method benchmarking.

Our method

Weekly high-resolution photogrammetric flights, planned around weather windows (coastal wind below 30 km/h). RTK GCPs fixed to the ground to ensure centimetric accuracy despite shifting sand. Detailed initial site mapping before earthworks to set a reference state. 3D progress modelling at each milestone (structure, finishes, civil works, landscaping). Specific tracking of landscaping work to validate contractual conformity.

What we delivered

• Detailed initial site mapping (orthophoto + DTM)
• Weekly photo/video reporting
• Textured 3D model at each contractual milestone
• Georeferenced photo tracking of landscaped areas
• Civil-works plans compared project vs as-built
• Earthworks fill and cut volumetrics in sandy ground
• Photographic documentation of the oceanfront façade
• Georeferenced as-built plan at site close-out

The outcome

Gregori International delivered the hotel on schedule thanks to the continuous steering enabled by drone monitoring. 3D modelling allowed investors and commercial teams to visualise the structure ahead of phase, accelerating pre-bookings. The complete georeferenced archive of the site remains available for future maintenance and extension operations.