Expanding your farm: why put energy in the permit file?

The permit file describes what you build and what you operate, and energy is part of both. Decide before you file how much power the expanded farm needs and how you will get it. A heavier connection with a cabin is one route. A semi-off-grid system is another. Solar panels and a battery carry the extra load next to the existing connection, so a cabin may not be needed.

You are planning a new stable. The architect draws the building, the environmental consultant works on the ammonia, odour and manure files, and the bank wants the figures. Nobody asks how many kVA the farm will need. That question comes later, from the electrician or the grid operator, when the permit is already on its way.

The catch is that energy decisions change the site plan. A medium-voltage cabin, a battery container, a generator with a fuel tank or a small wind turbine all need a place on the plan. Some need their own permit or notification. And the plans you get approved are the plans you must build, Inagro warns: build something else and it counts as unpermitted.

Dairy farmer Leen Mertens talked about environmental permits and the challenges of her farm in a PlattelandsTv interview. The project on her farm combines an extension with new technology. We were given the chance to think along and install a battery system. When green energy comes with a clear business model, everyone wins.

What does energy have to do with the environmental permit for a farm expansion?

The permit covers the buildings and the installations you operate, and several energy installations are among them. In Flanders, the omgevingsvergunning combines the planning side and the environmental side in one permit, applied for through the Omgevingsloket. Wallonia has the permis unique when a project needs both.

The animals, the stable and the manure are the heart of the file. But each energy choice adds a line to it. This table shows where the energy installations of a growing farm stand.

Each installation has its own article. Read about permits for a back-up generator, fire safety and permits for a business battery and small wind turbines on a farm. This article is about the moment you put them together: the expansion file.

Can your grid connection carry the expanded farm?

Check this first, because the answer decides half of your site plan. More cows or pigs means more milking robots, fans, manure scrapers and pumps, feeding systems and cooling. Those loads add up to a higher peak, and the peak decides the connection.

Ask the grid operator early, with a load list of the future farm. There are three possible answers:

• The existing connection can grow. Then a heavier low-voltage connection is enough, and energy stays a small line in your file.
• Only medium voltage will do. That is what a fast-growing dairy farm in Lokeren heard: Fluvius could not guarantee the power without a switch to medium voltage. That means a cabin and heavy cables on your land.
• The grid is full. In March 2026, fruit growers in Bierbeek asked to go from 250 to 400 kVA. Fluvius refused: the grid in their region was loaded to the maximum, VILT reported.

In Wallonia, ORES treats requests between 56 and 250 kVA as medium power. The detailed study is compulsory, paid and binding on cost and timing. Our article on low voltage or medium voltage for a business explains which grid you are on. If you already had a refusal, read what to do when a heavier connection is refused.

What does a medium-voltage cabin change in your permit file?

A cabin is a building on your land, with a transformer inside, so it touches both sides of the permit. It needs a spot on the site plan, an access route from the road and room for the cables.

Fluvius gives an idea of the size. A standard Fluvius cabin measures 345 by 270 cm on the outside and 337 cm high. It needs a free area of at least 5 by 6.1 metres. A customer cabin can differ. For cabins on private land, the Fluvius guide for local authorities says a permit is needed. Since 1 March 2026, Flanders exempts some technical constructions of general interest up to 30 m³ and 5 m high on private land. Ask your municipality whether your cabin falls under it, and draw it in the file either way.

The transformer itself has environmental rules. In Flanders, transformers are only classified above 1,000 kVA, the Departement Omgeving explains. From 100 kVA the conditions of VLAREM II chapter 6.13 apply. In Wallonia, a transformer from 100 kVA is a class 3 declaration, and from 1,500 kVA a class 2 permit.

Avoiding the cabin also takes a line out of your file. At a dairy farm in Londerzeel, avoiding the medium-voltage cabin was a requirement from the start. It meant an immediate saving of at least 60,000 euro, and no heavy cables on the property. The farm runs semi-off-grid on solar panels, a wind turbine and an LFP battery.

Our article on whether to build a high-voltage cabin or install a battery compares both routes in full.

Why does a low-emission stable depend on electricity?

Because many low-emission techniques run on power, and they only reduce emissions while they run. Under the Flemish nitrogen rules, a new stable must be built as a low-ammonia (AEA) stable, according to the Flemish government's questions and answers.

An air scrubber is a clear example. Drawing the stable air out and pushing it through the scrubber needs fans, and the scrubber needs a water pump, the EMIS technique sheet notes. So the technique that makes your permit possible adds a load that runs day and night.

That has two consequences for the energy plan. Count those loads in your load list. And think about what happens during a power cut: ventilation and scrubbers stop, and so does the milking robot. Our article on keeping barn ventilation running during a power cut covers the back-up side.

Do solar panels on the new stable roof need a permit?

Often not for the planning side, if they follow the roof. Since 1 March 2026, Flanders exempts solar panels on buildings other than homes in two cases. They are integrated in or on a pitched roof, or at most 1 metre above the edge of a flat roof. Protected heritage is the exception.

Wallonia has exempted many solar installations on roofs since 1 May 2025, within conditions. Ground-mounted panels are a different story. In Flanders, panels on the ground that do not stand next to a home almost always need a permit.

The real limit is often not the permit but the connection. A big stable roof can hold more panels than your connection may inject. Our article on more solar panels than your connection allows explains the options. With a battery or semi-off-grid, the panels feed your own loads first.

Generator, fuel tank and noise: what does the permit look at?

A back-up generator is usually not classified in Flanders if it stays a true emergency machine. That means below 400 kVA and less than 100 running hours a year, with an hour log. In Wallonia the rules start at smaller machines.

Three things catch farms out. A generator that runs every day as an energy source is no longer an emergency generator. A separate diesel tank has its own thresholds. And noise from the generator, fans and cooling units is part of how the neighbours and the municipality judge your file.

Our article on permits and inspections for a back-up generator goes through all of it. A battery can take over the short cuts, so the generator starts less often and stays in its emergency role.

Where does a battery fit in the permit file?

A farm battery above about 10 kWh has environmental conditions, so give it a spot on the plan. In Flanders it is not a classified installation, but the conditions of VLAREM II chapter 6.13 apply. In Wallonia it is a class 3 declaration.

Decide early whether it stands inside, in a technical room, or outside in a container. The fire service, the insurer and the distance to the stable all depend on it. Our article on business battery safety lists what they ask.

A battery can also make the expansion easier to plan. It covers the peaks of the new loads on top of the existing connection. In Londerzeel, the solar panels and batteries simply grow along when the farm expands. A modular business battery does the same on sites with a larger connection.

What should you settle about energy before you file the permit?

Five questions, answered before the architect finishes the plans.

What happens when you ask us to think along about your expansion?

We look at the loads of the future farm and at what your connection can carry, before the plans are final.

1. Step 1: Analysis and sizing. We list the current and future loads. If data is missing, we can monitor your consumption for a short period first.
2. Step 2: Technical design. We choose the solar power, the battery capacity and the inverter power, and where the system stands on your site.
3. Step 3: Installation and commissioning.
4. Step 4: Monitoring and support. You follow the system in the app and the VRM portal.

Our semi-off-grid systems are built for SMEs and farms with a standard 3 x 400 V + N connection, up to 75.6 kVA. Members of Boerenbond can also use the Boerenbond member quote request.