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Energy sharing in a condominium: the guide

· by Eric from OptimCE

Guide Energy community Administrative

In Belgium, 616,135 homes sit inside an apartment building in Brussels and Wallonia alone — 332,921 in the Brussels-Capital Region, 283,214 in Wallonia. In Brussels that is 56.8 % of the housing stock, against 16.3 % in Wallonia. And 88.8 % of those Brussels buildings were built before 1981.

Each of them has a common roof, a common-parts meter, and a dozen private meters whose consumption habits look nothing alike. On paper, that is the ideal configuration for sharing electricity: the most favourable tariff perimeter in the country, the widest diversity of quarter-hourly profiles, and no legal entity to set up.

In practice, the CWaPE’s evaluation report of 20 February 2025 counted just four same-building sharing operations across the whole of Wallonia. Four.

This article does not re-explain what an energy community is, nor what separates a CER from a CEC or a CEL — that is covered in “Energy communities in Belgium: CER, CEC, CEL”. It does not redefine collective self-consumption, set out in “Energy self-consumption in Belgium”, nor the allocation methods, compared region by region in “Allocation key in Belgium: the 3 regions”. Nor does it redo the mechanics of the two invoices, the mandatory statements and the VAT rates, detailed in “Invoicing shared electricity in Belgium”, or the table of the four Brussels tariff perimeters and the Walloon 80 % reduction, established in “Cheaper electricity without switching supplier”.

It answers a question those articles do not ask: in an apartment building, it is not energy law that blocks you — it is condominium law.

The regulator asks for an agreement and a form. Book 3 of the Civil Code, by contrast, sets three locks that no brochure ever mentions: the association of co-owners may not own the panels, the majority required depends on who does own them, and the managing agent’s mandate is shorter than the life of the project.

Comparison of the three possible ownership structures for a photovoltaic installation on the common roof of a Belgian condominium in 2026. In the first route, the co-owners finance the installation, which becomes a common part held in forced co-ownership: the decision is taken by a two-thirds majority at the general meeting, the injection point is the common-parts meter, the managing agent invoices on behalf of the condominium, and it is the condominium that must register for VAT above ten kilovolt-amperes. In the second route, a non-profit or a cooperative owns the installation under a right of superficies granted by the condominium: the decision requires four fifths of the votes, the legal entity holds the injection point, invoices itself and carries the VAT registration. In the third route, a third-party investor owns the installation under a right of superficies, also at four fifths of the votes: the condominium advances no capital but receives only a fee or a share of the revenue, and the value created leaves the building. A band at the bottom of the diagram recalls that the association of co-owners itself is the owner in none of the three routes, because article 3.86, paragraph 3, of the Civil Code limits its assets to the movable property necessary to preserve and administer the building.

The building is the best electrical perimeter in the country

Before turning to the locks, the stakes need to be clear — because they are real, and larger here than anywhere else.

Sharing electricity always routes the kilowatt-hours through the public grid, so network charges remain due. But the tariff applied depends on the electrical distance between producer and consumer. When both sit in the same building, that distance is minimal, and both regulators have drawn the consequences.

In Brussels, Brugel decision 285bis of 4 November 2024, applicable from 1 January 2025 to 31 December 2029, places same-building sharing in the most favourable perimeter of the grid: on shared volumes, the transport pass-through, the fixed term, the proportional term and the drawn-power term all fall to zero. In Wallonia, the 2026 ORES grid applies an 80 % reduction to the proportional term on energy shared within the same building, identified under globalisation codes E216 in distribution and E526 in transport. No reduction on residual electricity, and no reduction at all for sharing organised within an energy community.

The full table of the four Brussels perimeters is in “Cheaper electricity without switching supplier”; there is no point repeating it here. What is worth adding is what the building brings beyond the tariff.

The common-parts meter is a daytime absorber, and that is rare

Sharing is only valued within the quarter-hour: whatever is not consumed during the production slot falls back to plain injection, sold at the injection tariff. The structural problem of every sharing project is therefore to find consumers awake in the middle of the day.

An apartment building has one by construction. The lift, corridor and cellar lighting, mechanical ventilation, heating circulators, sump pumps, the garage door, car park lighting and, increasingly, charging points consume all day, without interruption or weekends. That is a stable daytime baseload a producer will find nowhere else without going out to canvass a school or a shop.

Sibelga puts it very well when describing who the participants are in a building: the producer, the common-parts meter or meters, the various homes, and possibly shops. The common-parts meter is not an accessory to the arrangement, it is its first customer.

Diversity of profiles is not decreed, it is observed

The other advantage lies in the building’s social mix. A fifteen-apartment block typically houses one or two retirees, a remote worker, a self-employed person, a family with young children, several people out at work all day and an empty flat between tenancies. That heterogeneity — endured, not chosen — produces an aggregate curve much flatter than that of an estate occupied by a single socio-professional profile.

That is the main reason a building absorbs better than a detached-housing neighbourhood at identical installed capacity. The logic of composing a sharing group by schedule rather than by affinity is developed in “Local electricity: the short-circuit guide”; in a building, that composition is largely already done.

What energy law asks of a condominium: very little

Here the contrast begins. Both Regions wrote a deliberately light regime — and in Brussels, the legal definition of a building describes, almost word for word, what a condominium is.

The ordinance of 19 July 2001 on the organisation of the electricity market, known as OELEC, has opened the right to share electricity since 30 April 2022. Its article 2, first paragraph, 56°, defines a building as “any non-temporary, covered and enclosed immovable construction comprising at least two units connected to the distribution network or the regional transmission network and comprising one or more common parts”.

Set that sentence next to the criterion that triggers condominium law: as soon as a building is divided into at least two apartments held by different owners and contains at least one common part. They are the same two conditions. The Brussels energy legislator has, without saying so, aligned its sharing perimeter with the perimeter of condominium ownership.

The conditions to meet fit into four lines, as the regional facilitator’s information sheet lists them:

  • the participants are located in the same building;
  • the generation installation is located in or on that building;
  • the shared electricity comes from renewable energy sources;
  • each participant remains covered by a supply contract with a supplier.

And the text adds, unambiguously, that “all occupants of the building who wish to — natural or legal persons, owners or tenants — may take part in electricity sharing, and the generation installation may belong to an occupant of the building or to a third party (e.g. the association of co-owners, third-party investors, etc.)”.

Four practical points, often overlooked, complete the Brussels picture:

  • No legal entity to create, no authorisation to request. Brugel does not intervene; the agreement is signed between the producer and each consumer, then the sharing is declared to Sibelga through an online form.
  • Exit is free. Either party may terminate the agreement, at no cost, with three weeks’ notice. That is a decisive argument to bring to the general meeting when facing reluctant co-owners: nobody is locked in.
  • The smart meter is free and Sibelga undertakes to install it within a maximum of four months from the request. Replacement is explicitly free of charge for sharing participants.
  • Gas cogeneration is excluded, for want of being renewable. That is why the Marius Renard association of co-owners in Anderlecht had to run its sharing under a derogation, closed in December 2023 — a useful precedent to know before building a project around an existing cogeneration unit.

Wallonia: a more generous definition, a longer procedure

The Walloon regime flows from the decree of 5 May 2022 amending the decree of 12 April 2001, and from the Walloon Government order of 17 March 2023, amended by that of 5 February 2026.

Its article 3, § 1, defines the building as corresponding “either: 1° to a fixed, covered and enclosed immovable construction comprising at least two parts intended to be used autonomously; 2° to several fixed, covered and enclosed immovable constructions belonging to the same condominium”.

That second point deserves emphasis, because it is more favourable than the Brussels regime and almost nobody exploits it: in Wallonia, a residential complex of several blocks belonging to a single condominium constitutes one single building for sharing purposes. Three blocks under the same deed of division may therefore share among themselves without creating an energy community, with the 80 % reduction on top.

Paragraph 2 of the same article adds that annexes — garages, gardens, car parks — and land form an integral part of the building, provided they sit on the same cadastral parcel, or have a common link or access with the building while being complementary or ancillary to it. The charging points in the underground car park are therefore inside the perimeter.

In exchange, the Walloon procedure is considerably more formal. Article 7 of the same order organises a cascading notification, with deadlines expressed in working days:

Step Regulatory deadline
The designated representative sends the form to the distribution system operator —
Acknowledgement confirming that the file is complete 10 working days
Verification of conditions and dispatch of the draft standard agreement 20 working days
Return of the signed agreement by the representative 10 working days
Effective start of sharing, by default 20th working day following receipt of the signed agreement
Suppliers informed by the operator at the latest 15 working days before the start

That means, at best and with a file complete on the first attempt, about sixty working days between notification and the first shared kilowatt-hour — close to three calendar months. An incomplete notification not regularised within six months lapses.

On the ORES side, the form goes to the operator’s dedicated address, together with its annexes: representative’s mandate, site plan, condominium declaration, list of participants and installations, storage declaration where applicable, custom allocation keys and sworn statements. The fact that a whole annexe is devoted to condominiums says a great deal about how often the case is expected.

Three technical prerequisites are not negotiable: every participant must have a dual-flow meter — communicating or AMR — and activate quarter-hourly metering with their supplier; the producer must give up compensation; and a protected customer must give up the social tariff on shared volumes.

Brussels and Wallonia, side by side

  Brussels Wallonia
Governing text OELEC of 19 July 2001, sharing open since 30 April 2022 Decree of 5 May 2022 and order of 17 March 2023, amended 5 February 2026
Definition of the building At least two units and one or more common parts At least two autonomous parts or several buildings of the same condominium
Annexes and car parks Not explicitly addressed Included if same cadastral parcel, or common link and ancillary use
Formality Online declaration to Sibelga Notification to the operator, cascading procedure
Lead time before start Tied to meter installation, four months maximum About 60 working days with a complete file
Legal entity No No
Regulator’s authorisation No No
Network advantage on shared volumes Most favourable perimeter: terms at zero −80 % on the proportional term
What must be given up Nothing specific Compensation; social tariff on shared volumes
Exit Termination at no cost, three weeks’ notice Modification to be notified to the operator

In other words: energy law has done its job. If the meters are in place and the residents agree, there is no regulatory obstacle to sharing within a building. The obstacle lies elsewhere.

First lock: the association of co-owners may not own the panels

This is the point every brochure glosses over, including the Brussels regulator’s own, which describes without blinking “a condominium [that] has a photovoltaic installation on the roof of its building”.

The Civil Code says otherwise. Its article 3.86, § 3, provides that “the association of co-owners may hold no assets other than the movable property necessary to fulfil its purpose, which consists exclusively in preserving and administering the building or group of buildings”.

Two words matter: movable and exclusively. Panels bolted to the roof, an inverter fixed to the plant room wall, embedded cabling: all of that becomes immovable by incorporation and forms an inherent component of the building. It is no longer movable property. The association, a legal person with strictly bounded assets, therefore cannot own it — and nor can it be granted an isolated real right over an inherent component.

This is not a doctrinal detail. Someone must be named as holder of the injection point with the operator, a VAT number may have to be opened, an injection contract signed, green certificates collected and liability for the works borne. Every one of those operations requires an identified owner. Only three structures hold up.

Route 1 — Co-owners in undivided ownership: the condominium invests

The installation is financed by the condominium and becomes a common part, held by the co-owners in forced co-ownership in proportion to their shares. The association does not own it; it administers it, which is exactly its statutory purpose. The injection point is in practice the common-parts meter, already in the association’s name.

This is the simplest structure to understand, the cheapest in the long run, and the one requiring the most attainable majority. It does, however, assume that the condominium has the capital — reserve fund, capital call, or collective loan — and accepts the technical risk over twenty-five years.

Route 2 — A non-profit or cooperative under a right of superficies

A separate legal entity, often set up by the co-owners themselves, is granted a right of superficies over the roof and becomes owner of the installation it erects there. It holds the injection point, it invoices, and it registers for VAT.

The benefit is real: membership of the legal entity is a personal right, independent of co-ownership status, which allows tenants to be included as members and leaves the building’s statutes untouched. The cost is equally real: incorporation, accounting, parallel governance, and a notarial deed for the right of superficies, which must be delimited and registered.

Route 3 — A third-party investor under a right of superficies

An external operator finances, installs, operates and owns, under a right of superficies granted by the condominium. The condominium advances nothing and receives a fee or a share of the revenue. This is the formula that lets a condominium without cash get started, and the one Brussels regulation expressly accepts — subject to the contractual condition, specified by Sibelga, that the customer remains owner of their injection.

The price is twofold: the majority required is the highest, and most of the value created leaves the building for the whole term of the contract.

What each route implies

  Route 1 — Undivided ownership Route 2 — Non-profit or cooperative Route 3 — Third-party investor
Majority at the meeting 2/3 (art. 3.88, § 1, 1°, b) 4/5 (art. 3.88, § 1, 2°, e) 4/5 (art. 3.88, § 1, 2°, e)
Notarial deed No Yes, for the right of superficies Yes, for the right of superficies
Who owns the installation The co-owners, undivided The legal entity The investor
Holder of the injection point The common-parts meter The legal entity The investor or the condominium, per contract
Who issues the sharing invoice The managing agent, for the condominium The legal entity The investor or its agent
Who registers for VAT above 10 kVA The condominium The legal entity The investor
Capital to raise In full In full, outside the association’s assets None
Where the value goes To the co-owners, via service charges To the members To the investor, apart from the fee

Note the paradox, because it drives the whole general-meeting strategy: the structure that costs the condominium nothing is the one requiring the hardest majority to reach. A condominium that cannot muster four fifths has no choice but to finance the project itself.

Second lock: the majority depends on who owns the installation

Article 3.88, § 1, of the Civil Code organises the qualified majorities. Three of its cases bear directly on a sharing project.

Two thirds of the votes for “all works affecting the common parts, with the exception of works imposed by law and conservatory works and acts of provisional administration”. Putting panels on the common roof falls into that category: it is an improvement, not a repair. Two thirds likewise for “any amendment to the statutes in so far as it concerns only the enjoyment, use or administration of the common parts” — useful if the condominium rules must accommodate the sharing arrangements.

Four fifths of the votes for “all acts of disposal over common immovable property, including the modification of existing real rights of use over the common parts in favour of a single co-owner”. That threshold applies as soon as a right of superficies is granted, whoever the beneficiary is. Four fifths too for “any acquisition of immovable property intended to become common”, and for “any other amendment to the statutes, including a change to the allocation of condominium charges” — this last case is the classic trap, because a poorly designed sharing arrangement leads people to want to change the charge allocation key in order to redistribute the revenue.

Unanimity, finally, for any change to the allocation of shares. Article 3.88, § 3, fortunately offers a release valve: where the meeting decides on works or acts of disposal by the qualified majority required, it may rule by that same majority on the change to the shares where such a change is necessary.

The trap is not the majority, it is the quorum

This is the mistake that costs most projects a year. Article 3.87, § 5, requires, for the meeting to deliberate validly, that more than half the co-owners be present or represented and that they hold at least half the shares — or, failing that, that those present represent more than three quarters of the shares. If neither quorum is met, a second meeting is convened after a period of at least fifteen days and then deliberates regardless of attendance.

In a building occupied mostly by tenants, where landlords rarely turn up, the first meeting often founders on the quorum. That does not kill the project, but it mechanically adds fifteen days and a fresh convocation.

Two procedural details deserve a mention in passing. The convocation must be sent at least fifteen days before the date of the meeting, and co-owners’ written proposals must reach the managing agent at least three weeks before the start of the statutory period for the ordinary meeting: a co-owner wanting sharing on the agenda must therefore start more than a month ahead. Finally, article 3.87, § 8, specifies that abstentions, void and blank votes are not counted as votes cast for the purposes of calculating the required majority — which, counter-intuitively, makes two thirds easier to reach than one might think in an undecided room.

Third lock: the managing agent’s mandate is shorter than the project

A photovoltaic installation lasts twenty-five years. The sharing agreement with the distribution system operator is open-ended. Brussels green certificates run for ten years.

The managing agent’s mandate “may not exceed three years”, under article 3.89, § 1, of the Civil Code. And the same provision adds: “Unless the general meeting expressly decides otherwise, the agent may not enter into any commitment for a term exceeding the duration of the mandate.”

The consequence is direct and rarely anticipated: the resolution instructing the agent to sign the sharing agreement must expressly authorise a commitment beyond the mandate. Without it the signature is fragile, and the question will resurface at the first change of agent — that is, statistically, before the end of the project.

The agent will not do for free what is not in the contract

The same article requires the relationship between the agent and the association to be set out in a written contract listing “the flat-fee services and the additional services and their remuneration”, and it rules bluntly: “Any service not mentioned may not give rise to remuneration, unless the general meeting decides otherwise.”

Yet managing a sharing operation is no symbolic task. The sharing manager must invoice shared electricity to each participant, declare the activity, notify every change — entry, exit, change of allocation method — and collect the related network charges to pass on to the operator. In Brussels, Sibelga sends the necessary data files every month; someone has to process them.

A meeting that votes the installation without voting the remuneration for that management is, in practice, voting a project that will never start. The point must appear explicitly on the agenda, as a costed additional service. The corresponding documentary burden on the Walloon side is detailed in “Energy community: CWaPE documents and deadlines”.

The handover list, to be written before you need it

At a change of agent, seven items must pass from one hand to the other, failing which the sharing becomes unbillable:

  1. the sharing agreement signed with each participant;
  2. the agreement concluded with the distribution system operator;
  3. the up-to-date list of participating EAN codes, with entry and exit dates;
  4. the allocation key in force and the meeting decision that adopted it;
  5. the transfer price voted and its effective date;
  6. the invoicing history, with its continuous legal numbering;
  7. the VAT returns and the green certificate records.

The owner votes, the tenant consumes

Here is the mismatch that in practice kills the most projects — and it is not legal, it is sociological.

The participant in a sharing operation is the holder of the supply point: the person whose name is on the meter, so the occupant. The general meeting, however, is made up of owners. In an average Brussels building, a substantial share of those owners do not live there and will never consume a shared kilowatt-hour. The Central Economic Council puts it bluntly about condominium renovation: most occupants are tenants, and thus face the landlord-tenant dilemma.

Energy sharing does not remove that dilemma, but it does reduce it — provided you face it rather than work around it.

Make the value flow both ways

The undivided-ownership structure has a property neither of the other two has: the proceeds of the electricity sale enter the condominium’s account and reduce the common charges, and therefore benefit the owners, landlords included. At the same time, the discount on the kilowatt-hour price benefits the occupants, and therefore the tenants. The same installation serves both populations through two different channels.

That is the argument to bring to the meeting, and it is better costed than merely stated: a landlord who consumes nothing still sees their share of charges fall, and their property gains a letting argument.

Design for turnover, not for the present moment

A rented building changes occupants constantly. Every move-out is a participant exit to notify to the operator, and every move-in a membership to offer. Three design principles follow:

  • Vote the price at the general meeting; do not negotiate it flat by flat. A single price, revisable annually, survives turnover; a mosaic of individual prices does not survive the second move. The defensible methods are compared in “Internal transfer price in an energy community”.
  • Choose a key that absorbs entries and exits. A key expressed in fixed percentages must be re-notified at every movement; a key proportional to consumption readjusts itself. The choice between the two logics is covered in “Allocation key in Belgium: the 3 regions”.
  • Inform at the point of the lease. The existence of the sharing, the price in force and the joining procedure must appear in the pack handed to the new occupant, alongside the house rules. That is the only moment when the information genuinely reaches an incoming tenant.

The governance side — informing participants, organising votes, keeping the news board — is developed in “Engaging energy community members”.

What it means in numbers, and the two tax traps

The ceiling is not the roof, it is the quarter-hour

A Brussels building averages 8.9 homes; a Walloon one, 6.2. A flat roof on a nine-home block easily takes 30 to 50 kWp.

It is not that capacity that determines the gain, but the fraction of output that finds a taker within the quarter-hour. The order of absorption in a building is almost always the same, and it is worth following:

  1. The common parts — lift, lighting, ventilation, circulators: a permanent baseload, absorbed first, and directly self-consumed at the injection point rather than shared;
  2. The car park charging points — the only genuinely controllable load in the building, and the most effective: shifting a charge from night to midday turns surplus injected for a few cents into shared electricity;
  3. Water heaters and heat pumps — shiftable by timer or connected thermostat, without any action from occupants;
  4. The homes — the rest, unmanaged.

What a kilowatt-hour of surplus is worth depending on how it is used is quantified in “Solar surplus: the 5 options compared”, and the overall profitability of an installation in “Solar panels 2026: still worth it in Wallonia?”.

Trap 1: the 10 kVA VAT threshold

Administrative decision no. E.T. 114.454 of 28 October 2014 holds that a local electricity producer with no other taxable activity, whose installation has a maximum AC capacity not exceeding 10 kVA, does not carry out an economic activity within the meaning of the VAT Code, given the small scale of its supplies.

A household sharing the surplus of six panels is therefore out of scope. A building roof never is. The Brussels regional guide puts it plainly: irrespective of any sharing arrangement, anyone with installations whose cumulative inverter capacity exceeds 10 kVA must register for VAT. In practice, roughly three equipped homes.

The nuance that saves budgets: registering for VAT does not automatically mean charging VAT. It remains possible to opt for the exemption scheme if annual turnover stays below €25,000, which covers the vast majority of building-level sharing operations. But a VAT number must still be opened and listings filed, which adds a recurring accounting cost whatever structure is chosen. It is the line item most systematically forgotten in general-meeting budgets.

The applicable rates and the mandatory statements on a sharing invoice are covered in “Invoicing shared electricity in Belgium”.

Trap 2: green certificates change scale on 1 April 2026

In Brussels, green certificate award coefficients are recalibrated each year by Brugel to target a seven-year payback. For new installations commissioned from 1 April 2026, the scale falls away sharply as capacity rises:

Installed capacity Change in coefficient
Up to 5 kWp No change
5 to 36 kWp −11 %
36 to 100 kWp −45 %
Above 100 kWp No green certificates at all

Since 1 January 2026, a RESCert certificate issued by a certified installer is also required for installations up to 5 kWp, without which access to green certificates is closed.

For a condominium the consequence is concrete: the 36–100 kWp band loses nearly half its support, and above 100 kWp there is none left at all. A large roof that would have been sized to the maximum in 2024 is now sized according to what the building actually absorbs, not what the surface allows. This is precisely where simulating the key and the quarter-hourly absorbable volume stops being a theoretical exercise.

On the Walloon side, the CWaPE for its part notes that the obligation to surrender green certificates on shared volumes is hard to justify for recent installations that no longer receive any, when the electricity concerned is guaranteed renewable and local — a correction that is expected but not yet secured.

The sequence that works, and how long it really takes

Projects that fail almost never get the technology wrong. They get the order wrong: they vote before they know, or they choose the structure after asking for quotes. Here is the reverse sequence.

Timing What you do Why now
T‑12 months A co-owner or the condominium council notifies the item to the managing agent Written proposals must arrive at least three weeks before the statutory meeting period
T‑11 Request the electrical perimeter and consumption history from the operator Without load curves, any costing is an opinion
T‑10 Call on the regional facilitator, free of charge It provides economic analysis tools and agreement and invoicing templates
T‑9 Choose the ownership structure That choice, and only that choice, sets the majority to reach: 2/3 or 4/5
T‑8 to T‑5 Quotes, financing plan, simulation of the key and absorbable volume A meeting votes on a figure, not an intention
T‑4 Convocation, at least fifteen days before the meeting Anticipate a failed quorum and the second meeting fifteen days later
T‑3 General meeting: structure, budget, price, key, agent’s mandate beyond term, management fee Five resolutions, not one
T‑3 to T+1 Request smart meters for every participant Up to four months’ lead time in Brussels; this is the critical path
T‑1 Sign the sharing agreements with each participant The agreement precedes the declaration
T‑1 Declare to Sibelga or notify the Walloon operator Allow about 60 working days in Wallonia
T0 Sharing starts Suppliers are informed at the latest 15 working days beforehand
Every year Review the price, the key, the participant list; report A sharing operation is steered, not installed and forgotten

The critical path is neither the vote nor the paperwork: it is the smart meters. In a building where several participants still lack one, that is the only step no meeting decision can accelerate. It deserves to be launched the day after the vote, not at declaration time.

Key takeaways

  1. The building is by far the best sharing configuration in the country. The most favourable tariff perimeter in both Regions, an endured but real diversity of profiles, and a common-parts meter that consumes all day. None of that exists on a housing estate.

  2. Energy law is not the blocker. No legal entity, no regulator’s authorisation, no change of supplier: an agreement, a form, communicating meters. In Brussels, the legal definition of a building is even aligned with that of a condominium.

  3. The association of co-owners may not own the panels. Article 3.86, § 3, limits its assets to the movable property necessary for its purpose; panels fixed to the roof are not that. A real owner must therefore be designated: the co-owners undivided, a legal entity, or a third-party investor.

  4. The majority threshold follows from the structure, not from the works. Two thirds if the condominium invests and owns; four fifths as soon as a right of superficies is granted. The structure that costs nothing is the one requiring the hardest majority.

  5. The managing agent’s mandate is shorter than the project. Three years maximum, and no commitment beyond it without an express decision of the meeting. That authorisation, the management fee and the handover list must be voted the same day as the installation.

  6. The owner votes, the tenant consumes. The undivided-ownership structure is the only one that returns value to both populations: the proceeds reduce the owners’ charges, the discount reduces the occupants’ bills. That is how it should be put to the meeting.

  7. What not to expect from it: sharing does not make network charges on residual electricity disappear, does not remove the need for a supply contract, and does not turn an oversized roof into an annuity — since 1 April 2026, in Brussels, above 100 kWp there are no green certificates at all. The volume that counts is what the building absorbs within the quarter-hour, not what the roof can produce.

Set up your building’s sharing with OptimCE

Open-source platform built for Belgian energy communities: members, meters, allocation keys and sharing operations in one place — right down to simulating the volume your building can genuinely absorb within the quarter-hour, before you even convene the general meeting.

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FAQ

Can a condominium share the electricity from its roof between the apartments?

Yes, and it is the lightest arrangement in Belgian law. In Brussels as in Wallonia, sharing within the same building requires neither a legal entity nor an authorisation from the regulator: an agreement between the participants and a declaration to the distribution system operator are enough.

The four conditions are identical on both sides of the regional border: participants are located in the building, the generation installation is in or on that building, the shared electricity is renewable, and every participant keeps a supply contract.

The difficulty is therefore not obtaining permission to share. It is deciding who owns the installation that feeds the sharing — and that question belongs to the Civil Code, not to energy law.

What majority is required at the general meeting to install solar panels on the common roof?

Two thirds of the votes if the condominium finances and owns the installation itself, under article 3.88, § 1, 1°, b, of the Civil Code, which covers “all works affecting the common parts”.

Four fifths, by contrast, as soon as a real right is granted to a third party — third-party investor, cooperative, non-profit — because you then fall under 2°, e, of the same paragraph, which covers “all acts of disposal over common immovable property”.

The threshold therefore depends not on the nature of the works but on the ownership structure chosen. That is counter-intuitive, and it deserves to be settled before a single quote is requested.

Can the association of co-owners own the installation?

No, not strictly speaking. Article 3.86, § 3, of the Civil Code provides that “the association of co-owners may hold no assets other than the movable property necessary to fulfil its purpose, which consists exclusively in preserving and administering the building”.

Panels bolted to the roof, however, become immovable by incorporation and fall outside that category. It is the co-owners who own them in forced co-ownership, in proportion to their shares; the association merely administers.

The distinction looks academic until the day someone must be named as holder of the injection point, a VAT number must be opened or an apartment is sold. At that moment, it decides everything.

Can tenants take part in the building’s energy sharing?

Yes, and in most buildings they even form the majority of participants. Brussels regulation says so explicitly: all occupants of the building who wish to, owners or tenants, may take part.

The participant in a sharing operation is the holder of the supply point, so the person whose name is on the meter — the occupant, not the owner of the wall.

This creates a mismatch that has to be accepted from the design stage: the meeting that votes is made up of owners, many of whom will never consume a shared kilowatt-hour, while the discount will benefit tenants who did not vote. The proceeds of the sale go to the condominium and reduce the charges, which partly closes the loop.

Do you need to create an energy community to share within a building?

No, and that is precisely the point of the same-building regime: these are active customers acting jointly, not a community.

An energy community only becomes necessary once you leave the building — several buildings not under common ownership, participants elsewhere in the municipality — or when the electricity is not renewable.

That is why a natural gas cogeneration unit cannot feed a Brussels same-building sharing operation, and why the Marius Renard project in Anderlecht had to operate under a derogation, closed in December 2023.

Note, however, the Walloon particularity: several constructions belonging to the same condominium count as one single building. A complex of three blocks under the same deed of division therefore stays within the light regime.

What happens to the sharing if the managing agent changes?

Nothing, provided it was anticipated. The managing agent’s mandate may not exceed three years, and article 3.89, § 1, states that, “unless the general meeting expressly decides otherwise, the agent may not enter into any commitment for a term exceeding the duration of the mandate”.

Since the agreement with the distribution system operator is open-ended and the installation lasts twenty-five years, the resolution of the meeting must expressly authorise that commitment beyond the mandate.

The handover must then be organised: sharing agreement, agreement with the operator, list of EAN codes, key in force, price voted, invoicing history and VAT returns. A sharing operation orphaned of its representative does not stop by itself — it simply becomes unbillable.

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