This is probably the fastest-growing segment in Suisse romande since 2023. PPEs voting for a solar installation are no longer an exception. Between Geneva, Lausanne, Vevey, Fribourg, and Yverdon, roughly one in five general assemblies now considers the question in the current agenda. And rightly so: the collective return on a PPE installation is almost always higher than on an equivalent individual home.
The subject, however, is more legal and administrative than technical. The installation itself proceeds like any detached house project. It is before and after where care is needed.
Why solar is more profitable in a PPE than on an individual home
The calculation hinges on a single figure: the self-consumption rate. An individual home often plateaus at 30–40 % self-consumption, because no one is consuming at midday when production is at its peak. A PPE of 6 to 12 dwellings, through pooling, regularly achieves 65 to 85 %.
Three reasons for this. First, consumption profiles complement each other: there is almost always someone at home — a home-worker, an elderly resident, a parent with young children. Second, shared services (corridor lighting, lift, ventilation, shared heating) consume continuously and absorb a stable share of production. Third, the installed capacities in a PPE often allow optimal orientation and tilt across a larger roof.
In concrete terms, on a 35 kWp PPE installation of 6 dwellings in Lausanne in 2024–2025, we recorded an average annual collective self-consumption of 78 %, whereas the same volume installed on 6 individual homes would barely have exceeded 35–40 %. This gap changes the profitability: we are talking about a return on investment of 6 to 8 years for a well-designed PPE, versus 9 to 11 years on an individual basis.
The assembly decision: what to anticipate
This is the step that stalls things most often. Not from principled opposition, but from poor preparation of the file.
The PPE by-laws. The first thing to read before proposing the project. Most Vaud, Geneva, and Fribourg by-laws specify particular majorities for works. Solar on the roof is generally classified as an "improvement", votable by simple majority. But some older by-laws speak of "roof modifications" and require a qualified majority (often two-thirds, or even unanimity). Read first, propose afterwards.
The presentation file. It should run to four to eight pages, no more. It covers: gross cost, net cost after grants, allocation by thousandths or by consumption, self-consumption method (RCP or not), maintenance, insurance, and guarantee. A serious installer provides this file as standard, ready to attach to the agenda.
Ideally two variants in the quote. Many PPEs want to deliberate on two options (with battery / without battery, or 30 kWp / 40 kWp) rather than a binary choice. This eases the decision and gives the property manager a pivot point.
The installer's presence at the assembly. For larger PPEs, we consistently recommend attending the general assembly to answer technical questions. This is what unblocks undecided votes. Half an hour of direct exchange avoids three months of subsequent emails.
The RCP: the central mechanism for PPE profitability
The self-consumption grouping is governed by the Energy Act. It allows co-owners to collectively consume their solar production rather than feeding it into the grid and buying it back at consumer prices a few hours later. The tariff difference (between 25–32 ct/kWh on purchases and 8–14 ct/kWh on feed-in) stays with the PPE.
On the technical side, the RCP requires:
- A solar production meter at the installation level.
- Individual meters per unit, capable of measuring self-consumption and grid consumption.
- A single exchange meter with the grid operator (Romande Energie, SIG, Groupe E).
- An RCP by-laws document voted by the assembly and signed by each co-owner.
The RCP by-laws set the internal tariff (often aligned with the average distributor price, sometimes slightly below as an incentive), the billing frequency (monthly or quarterly), and the management of co-owner entry and exit.
Indicative cost of setting up an RCP in 2026: CHF 3,000 to CHF 6,000 in addition to the PV installation itself, mainly for cabling, meters, and commissioning. This is quickly recouped at the scale of a PPE.
How to allocate production between units
Three approaches are used in practice in Suisse romande.
By PPE thousandths. Proportional to the shares in the by-laws. Simple to understand, simple to vote. But inequitable in the long run: a large, rarely occupied flat receives the same share as a large, heavily occupied one. Typically adopted when the PPE has homogeneous profiles and wants to avoid individual meters.
By actual consumption. Each unit is charged according to its effective consumption from solar production. This is fair, but requires meters and a management system (often a communicating meter with a cloud platform). This is the majority option in 2026 for new PPE developments.
Hybrid. A fixed share by thousandths (shared charges, lift), and a variable share by actual consumption (the portion attributable to units). More equitable, more complex to manage. Reserved for PPEs that already have advanced energy accounting.
Our recommendation: actual consumption, except for small PPEs of four units or fewer where the difference is negligible and simplicity wins.
Costs for a typical PPE in 2026
Let us take a 6-dwelling PPE in Lausanne with a usable roof area of around 200 m². A 35 kWp superimposition installation on tiles, Aiko panels, Fronius inverter, RCP, individual meters.
- Gross PV installation: CHF 64,000
- RCP system (meters, commissioning): CHF 4,500
- Gross total: CHF 68,500
- Pronovo lump sum: –CHF 12,500
- Cantonal grant Vaud: –CHF 4,000
- Municipal aid (depending on location): CHF 0 to CHF 3,000
- Net after grants: CHF 49,000 to CHF 52,000
That is approximately CHF 8,200 to CHF 8,700 per unit before individual tax deductions. Each co-owner can then deduct their share from taxable income, reducing the effective net to CHF 5,500–6,500 per unit. For this investment, each unit benefits from an attributed annual production of approximately 5,500 kWh, of which 75–80 % is self-consumed.
For a flat consuming 4,000 to 5,000 kWh per year, that is the equivalent of virtually the entire annual electricity bill, paid once for CHF 6,000 over 25 years.
The legal points to secure
A few details, often overlooked, that protect the operation over time.
Ownership of the installation. The installation belongs to the PPE as a whole. It is a common part under law. No co-owner may claim exclusive ownership of any portion.
Insurance. The installation is declared under the PPE's building insurance. The additional premium is minimal, sometimes zero up to a certain threshold. Many PPEs overlook this point and find themselves without cover in the event of storm damage.
Maintenance. To be included in the PPE's annual budget: monitoring (often included in the first year by the installer), cleaning every three to five years depending on the environment, inverter checks. Allow CHF 200 to CHF 500 per year for a 35 kWp installation.
Exit of a co-owner. The RCP follows the unit, not the person. The new owner takes over the previous owner's position. The RCP by-laws must state this explicitly to avoid any ambiguity.
Amendment of the PPE by-laws. If the installation changes the use of the loft or roof (which is rare), it may be appropriate to update the by-laws. In the majority of cases, this is not necessary.
The typical timeline for a PPE project
From the first idea to commissioning, allow six to ten months for a well-prepared PPE. In detail:
- Months 1–2: technical study, quote, presentation file.
- Month 3: assembly, vote, contract signature.
- Months 3–4: cantonal grant submission and grid operator notification.
- Months 5–7: installation (typically five to ten days depending on size).
- Months 7–8: commissioning, RCP operational.
- Months 8–12: Pronovo lump sum payment.
For PPEs that put a file to vote without preparation, 12 to 18 months between the first quote and installation is regularly observed. The difference is made during preparation, not on site.
Our perspective for 2026
Solar in a PPE is, in 2026, the most profitable segment in the Suisse romande market. Better than an average individual home, better than an isolated renovation. The obstacles are almost never technical or financial. They are organisational.
A PPE with an engaged property manager, a clean file, and an installer who attends the assembly almost always votes the project through. Conversely, a poorly prepared file can stall for three years in assembly on the same objections, even though the calculation is largely favourable.
The right reflex for 2026: if your PPE has not examined the question since 2022, the market has changed. Prices have fallen, grants are stable, the RCP framework is better defined. A new quote, on the current basis, deserves a place on the agenda at the next general assembly.