Solar Panels in Condominiums: How the Decision Is Made

This is the misunderstanding that sinks the most projects at the assembly. Someone presents the proposal saying the panels will lower the apartments' electricity bills, and that is not how it works.

A small-scale self-generation system connects at one specific commercial metering point —where the retailer measures and bills— and offsets the consumption of that point. A residential complex has many: one per apartment, plus the common-areas meter the administration pays. A system installed on the roof normally connects to the latter.

That means what falls is not each household's bill but the common consumption: lifts, pressure and ejector pumps, corridor and car park lighting, the gatehouse, tank pumps, automatic gates and, increasingly, electric vehicle chargers. In a large complex that account is far from trivial, and it has an advantage we have covered elsewhere: much of that load happens during the day, when the system generates.

Splitting one system's generation across each apartment's individual metering points is a different matter, and not something a condominium can take for granted: ask the network operator and the retailer in writing before promising anything at the assembly. A proposal promising savings on every household bill without that consultation is selling a result it does not control.

Ley 675 de 2001 defines common property as the parts of the building belonging undivided to all owners of private units, which by their nature or purpose enable the functioning, conservation or use of the private units (art. 3). The roof falls squarely within that: it belongs to no one in particular and to everyone at once.

The practical consequence is direct. No co-owner —not the top-floor one, not the one with terrace access— may install a system on the roof by their own decision. Nor may the building manager: their duties (art. 51) cover management and conservation, not disposition over common property.

There is one exception worth checking before anything else, because it changes the whole project. Article 22 allows common property not needed for general enjoyment to be assigned for the exclusive use of a private unit, and it names terraces and roofs explicitly. If the horizontal property bylaws assigned the roof to a particular apartment, the condominium does not freely dispose of it and the matter must be settled with that owner before any vote.

That is why the first document to read is not a quote: it is the horizontal property bylaws, with the property registry certificate to hand.

This is where most commercial proposals tiptoe past, and it is the question the assembly will ask.

The general rule is that decisions are taken by a majority of the coefficients represented at the meeting, with a quorum of more than half of the co-ownership coefficients (art. 45). But article 46 lists, as an exception, ten decisions requiring a qualified majority of seventy percent (70%) of the coefficients of the building or complex. Two of those items bear directly on a solar project.

Item 3 requires 70% for the approval of common expenses other than the necessary ones. Necessary expenses are those sustaining administration, maintenance and repair of common property; installing a generation system that did not exist before is an improvement, not a repair. On that reading —the usual one— a solar project needs 70% regardless of its cost.

Item 2 requires the same majority for imposing extraordinary levies whose total amount, during the budget year, exceeds four (4) times the value of the monthly necessary expenses. It is a concrete, verifiable threshold: if the year's total levy exceeds four monthly fees, the qualified majority is triggered. A system sized for a complex's common areas usually clears that threshold comfortably.

The exact classification of an expense depends on each condominium's bylaws and admits legal debate, so the prudent course is to plan the project assuming 70% will be needed, and to consult a lawyer before the assembly if you intend to argue otherwise. Arriving at the meeting with the wrong majority in mind costs a year.

The financing route is not merely a cash question: it determines what is put to the vote and under which majority, and that decides whether the project happens at all.

A levy —an extraordinary expense each owner pays according to their coefficient— is the most direct route and the hardest to approve, because it asks a large group of people in different financial situations for money up front. It is also the one that unambiguously triggers the item 2 threshold once it exceeds four monthly fees.

A loan in the name of the condominium's legal entity moves the payment into the annual budget, in instalments. It is still an assembly decision and still requires 70% as a non-necessary expense, but it is far easier to defend: the argument stops being how much everyone must put in and becomes whether the loan instalment is smaller than the saving on the common bill.

Contracts where a third party installs and maintains the system while the condominium pays for the energy or the service exist in the Colombian market under various names. They avoid the upfront investment but commit the condominium for long terms —often ten years or more— and it is worth examining carefully what happens at the end, who keeps the asset, what occurs if the roof must be worked on, and how the price is indexed. A contract of that duration is also an assembly decision, not one for whoever happens to be managing the building.

Whichever route is chosen, one question is better resolved before the meeting than after: what happens when someone sells their apartment. The system stays with the common property and the saving stays in the monthly fee; the departing owner takes nothing and recovers nothing. Saying so plainly from the outset defuses half the objections.

If the system feeds the common account, the saving is common too. It reaches each apartment by an indirect but real route: a lower common-areas bill means a lower administration budget, and therefore a lower monthly fee than it would otherwise have been.

The split is not negotiable: Ley 675 establishes that the co-ownership coefficient determines the share with which each owner contributes to common expenses (art. 25). The same coefficient that sets how much each puts in for the investment sets how much they receive from the saving. It is proportional by definition, and worth stating at the assembly because the split is the first suspicion to surface.

It is also worth being honest about magnitude. A complex's common-areas consumption is split across dozens or hundreds of apartments, so the effect on an individual fee is modest even when the total saving is substantial. Presenting the project as a dramatic cut to the monthly fee sets up a disappointment; presenting it as what it is —a sustained reduction in a shared cost that will only rise over the years— is defensible and holds up over time.

An assembly cannot approve what it cannot evaluate. Most solar projects in condominiums are not rejected: they are postponed, because nobody could answer the questions from the floor. Having this settled in advance saves a year.

The first is already stated, and it is the most common: promising in the notice of meeting that apartment bills will fall. When someone at the assembly asks and the real answer is that the administration fee falls, the proposal loses all credibility even if the project was sound.

The second is sizing for the available roof instead of for the common consumption. In a complex the temptation is strong, because the roof is usually generous and the installer charges by installed capacity. But surplus delivered to the grid is recognised under article 25 of Resolución CREG 174 de 2021, as amended by Resolución CREG 101 072 de 2025, at a value that need not equal the avoided tariff. An oversized system costs more and does not save in proportion.

The third is not looking at the roof before the panels. A system has a service life measured in decades; if the waterproofing is near the end of its cycle, it gets redone first, not later. Dismantling and reinstalling a system to fix the roof is a cost nobody budgeted and an argument nobody wants to have in assembly.

The fourth is approving without a proper record. The decision, the majority reached and the exact scope of what was approved must appear in the minutes, with the coefficients that voted in favour. A project of this size approved on ambiguous minutes is a challenge waiting to happen, and the person left with the problem is the manager who executes it.