Measuring roofs by drone before solar panels go on, in Martinique and French Guiana
Before installing panels on an existing roof, the installer needs to know the roof’s geometry and structure: dimensions, slopes, obstacles, purlin positions. In 2026 we carried out these measurements by drone for three solar companies, Albioma Solaire in French Guiana and Martinique, Voltadom in French Guiana and So Watt in Martinique, on housing estates, care facilities, commercial buildings and an airport shed.
What the installer asks for
For each building, Albioma Solaire Caraïbes’ standard list includes:
- the building dimensions: length, width, height;
- the ridge length;
- the rafter length;
- the pitch of each roof slope;
- the dimensions of roof obstacles, such as access hatches or solar water heaters;
- the purlin spacing, between purlins and from the roof edge;
- the height of the various points of the roof;
- close-up photos to assess the condition of the roofing and the work required.
The drone flies a photogrammetric grid over the building; the orthophoto and 3D model are then used to take the dimensions, which are drawn on a PDF plan. The roof orthophotos delivered to Albioma Solaire in French Guiana in May 2026 reach 6 mm per pixel.
The freight shed at Aimé Césaire airport
In March 2026 Albioma Solaire Caraïbes consulted us about the freight shed at Martinique Aimé Césaire international airport, in Le Lamentin. As the flight area lies within the airport perimeter, the airport operator’s authorisation, from SAMAC, was requested by the client and obtained on 9 April. The flight took place on 17 April and the deliverables were handed over on 21 April 2026, four days later.
Coach screws: hundreds of measurements per building
Some installers also ask for the axes of the lines of coach screws and their spacing, which are used to lay out the panels. Drawing these axes requires a very high image resolution at flight time and substantial processing time: hundreds of measurements are quickly reached, even for a simple building. On metal-sheet roofs, these lines of coach screws also give the position of the purlins. When these measurements are requested, we fly as low as possible.
That was the case in June 2026 at the Les Amandiers housing estate in Le Lamentin, where two roofs were surveyed, one with all its dimensions and the other for the size of its rooflights, delivered on 5 June. In September, in Kourou, Voltadom wanted to know, for each roof of a specialised care home, the distance between the lines of coach screws: delivered on 17 September.
Without coach screws: dimensions only
When the need is limited to dimensions, i.e. 2D and 3D lengths with slopes and spot heights, the plan shows only those measurements. That is what Voltadom chose in June 2026 for three care facilities in French Guiana, a shelter, an institute and a sheltered workshop: the sheltered workshop was delivered before the end of the month, the other two sites were captured on 30 June and everything was available on 1 July.
Three sites in one day
In September 2026 So Watt entrusted us with three industrial sites in Martinique. All three were captured on 24 September; the digital products were delivered on the 29th and the plans, with axes and spacings checked against the panel layout, were finalised on the 30th.
These measurements extend the roof inspections we have carried out for installers since 2020: a single flight provides the orthophoto, the 3D model and the roofing photos, and the plan shows the dimensions requested by the installer’s design office.
