Frequently asked questions

A drone applies water and, where needed, a cleaning product to the facade or glass, using softwash at low pressure or pressure washing up to 200 bar, depending on the surface. A pilot flies it from the ground, inside a marked safety perimeter. That means no aerial work platform (cherry picker), scaffolding or gondola (building maintenance unit, BMU), and no rope access. We plan every job in advance and report on it afterwards on the platform, our client portal.

We use water purified by reverse osmosis, a process in which a membrane removes the dissolved minerals. With no lime or salts left in it, the water dries without streaks or limescale spots. For a drone, that matters: nobody follows up with a squeegee, so the water has to dry clear on its own.

Yes, provided the safety perimeter on the ground is respected. During the flight we cordon off an area below and around the work zone that nobody enters. We set that perimeter in advance, during the site visit or remote assessment, taking into account the entrances that must stay open. It also means nobody works at height: there is no window cleaner on a rope and no aerial work platform parked at your entrance.

Besides purified water, we use enzymatic and chemical products, depending on the dirt and the surface. The enzymatic products break down organic dirt and keep working after a single application. Industrial facades such as sandwich panels and metal cladding get their own products.

Not entirely. After cleaning we can apply a dirt-repellent coating. Dirt sticks less and rain carries more of it away, so the glass stays clean for longer and cleans can be spaced further apart. The glass does not clean itself, though, and it will need another clean in time.

We don't fly in strong wind or rain. When the weather turns, we reschedule the job for a date agreed with you. The method has limits too: heavy crusts or graffiti sometimes need a different technique. There also has to be room on the ground for a safety perimeter. If any of this rules out your building, we'll tell you in the first call or during the site visit.

The price depends on the surface area, the material, how dirty it is and how easy the building is to reach. After a site visit or remote assessment, you receive a quote.

Mainly access to the site, space on the ground for the safety perimeter, and the practical points we go through during the site visit. We also ask about the surroundings, such as entrances that must stay open and the busiest times of day. That way we can schedule the job when it disturbs the building least.

There are five steps: a 30-minute intro call, a site visit or remote assessment, permit and planning, the cleaning or inspection itself, and the report on the platform. You plan the first call straight into our calendar.

Yes. Spraying from a drone, including to clean a building, falls outside the open category and requires an operational authorisation in the specific category (EU Regulation 2019/947). In Belgium, that authorisation is granted by the Directorate-General Aviation of the FPS Mobility and Transport (Federal Public Service). The specific category covers drone operations with more risk than the open category, based on a risk assessment the operator submits in advance.

No. The authorisation to fly and spray is our responsibility as the operator. What we need from you is consent from the owner or manager to work above and around the building, plus information about its surroundings. If the safety perimeter extends onto public land, we check during the site visit whether extra permission is needed and who should apply for it.

The platform is OPPY's client portal at portal.oppy.group. You use it to plan jobs, follow their status and find the report after each one, alongside the full history of every building. Many drone cleaners sell a flight; we run a maintenance programme for each building, from planning to report.

Every report contains before and after photos and the findings, each pinned to its location on the facade or roof: loose elements, damaged joints, spots where dirt keeps building up. You find it on the platform, in that building's history. You can export it as PDF or CSV for your maintenance plan or ESG reporting.

Access to the platform is set per user. Each colleague, technical team or outside contractor gets their own login rather than a shared password. When someone no longer needs access, only their login is switched off. How we handle personal data is set out in our privacy policy.

In Belgium, usually a few per cent, not tens of per cent. A European study by DLR (Renewable Energy, 2024) puts the average annual soiling loss at 0.9% if rain is counted as perfect cleaning, and up to 5.3% if rain removes only 10% of the dirt. Belgian measurements found roughly 3 to 4% power loss from dust at a 35° tilt. Cleaning makes most sense with bird droppings, on flat roofs and for panels near farmland, railways or industry.

There is no universal interval: on many roofs, rain does most of the work. Cleaning makes most sense on flat or low-pitch industrial roofs, where dirt and water sit, on panels near farmland, railways or industry, and where birds are a problem. A drone inspection shows how dirty your panels really are, so you can decide from images rather than a fixed schedule.

That depends on the panel manufacturer. Some warranty terms restrict cleaning methods or treatments applied to the glass, so we check them before proposing a coating. If you would rather take no risk at all, we can clean the panels with purified water only, without a coating.

Yes. Cleaning companies, window cleaners and facility service providers can offer drone cleaning to their clients without investing in drones, pilots or permits. We carry out the work as your subcontractor, under your name (white label) or under both names (co-branded), with the report on the platform. You keep the client relationship.

Plan a 30-minute intake call from our pilot page. We are looking for drone pilots, and also for window cleaners and facade cleaners who want to make the switch. You need an EU drone training certificate, a driving licence and good physical fitness; experience in the specific category is a plus. We provide training on our cleaning system, the equipment and the schedule.