A proper solar consultation takes one to two hours, happens on site, and is usually free with installation companies, because it's part of preparing the quote. Independent energy consultations, by contrast, bill on a time-and-materials basis. How to spot quality: at the end you have a roof survey, a yield estimate, a system concept and a comprehensible cost breakdown – not just a number on a sheet. (As of: August 2026)
Key points in brief
- With an installation company, the consultation is usually free and without obligation; it's part of the quote.
- Independent consultation without a sales interest also exists – chargeable, useful for complex properties and apartment buildings.
- A remote consultation over the phone is enough for a ballpark figure, not for a quote: substructure, meter box and cable routes can only be seen on site.
- Prepare three things: your electricity bill, details about the roof, and your plans for the coming years (heat pump, EV).
- The result of the consultation isn't «a price» but a comprehensible concept – the 15 questions help you check that.
What actually happens in a solar consultation
A consultation worthy of the name has four parts – and the order already reveals a lot about the company.
First your situation, not the product. How high is electricity consumption, how is it distributed over the day, what's planned for the coming years? A household switching to a heat pump in two years needs a different system from one that won't. Anyone who skips this part and jumps straight to modules is selling a product instead of a solution.
Then the roof – on site. The map gives you orientation and tilt, but nothing else: the condition of the covering, the substructure, shading from neighbouring trees over the course of the day, accessibility for scaffolding. Plus a look in the basement, because that's where it's decided how involved the electrical connection will be. A company that issues a binding quote without a site visit has either calculated on a flat-rate basis or is counting on add-ons later.
Then the concept. System size, number of modules, inverter, whether a battery makes sense – and why, with reasons. This is also where the word «no» belongs: not every roof can carry full coverage, and not every household needs a battery.
Finally the numbers. Investment, expected production, incentives, self-consumption share, the order of magnitude for payback – as a range with stated assumptions, not a promise. Anyone who gives you an exact payback figure to the year is calculating with assumptions nobody actually knows: future electricity prices, your consumption behaviour, the feed-in remuneration in ten years.
What does a solar consultation cost?
| Type of consultation | Costs | Makes sense when … |
|---|---|---|
| Consultation by the installation company | usually free, part of the quote | standard single-family-home case |
| Independent energy consultation | time-and-materials, chargeable | complex property, apartment building, renovation planning |
| Municipal/cantonal initial consultation | sometimes subsidised or free | first orientation, incentive questions |
| Online calculator | free | ballpark figure before the first conversation |
Overview, as of: August 2026. Offerings from municipalities and cantons differ widely – it's worth checking your municipality's energy webpage.
The installer's free consultation isn't a contradiction to being reputable: it's the effort a company puts in to be able to calculate a quote, financed through the order. It only becomes a conflict of interest once the recommendation stops fitting the situation – for example, if the battery is always included regardless of the consumption profile. That's exactly what the warning signs of reputable and disreputable providers are for.
Conversely, paid, independent consultation has its place: for apartment buildings with a ZEV question, for condominium ownership, for a full renovation in which the solar system is just one building block. There it doesn't replace the quote, but structures the decision that precedes it.
What you should prepare
Three things make the difference between a general conversation and a solid foundation:
1. Your last electricity bill – ideally the annual statement with peak and off-peak tariffs. From this, the specialist company reads consumption and tariff structure, both key input figures. 2. Details about the roof – year built, last renovation, covering. If available: a floor plan or roof plan. A first indication of area and orientation is provided by sonnendach.ch. 3. Your plans – heat pump, EV, renovation, a planned sale. These points shift the sensible system size more than any technical detail question.
Anyone who wants to know the ballpark figure before the conversation can find it out themselves: our solar calculator reads the federal government's official roof data for your address and shows possible capacity, a guideline range and how incentives apply. This doesn't replace the site visit – but you go into the conversation with a number in mind instead of a blank sheet.
How to recognise a good consultation after the appointment
The most honest test comes afterwards. Look at what's actually on the table:
- Is the system size justified – from roof area and consumption – or just set?
- Does the quote show individual line items, or just a bottom-line total? Which items belong there is shown in the article Cost line items in a solar quote.
- Are the assumptions stated: which feed-in tariff, which self-consumption share, which electricity price was used?
- Were you advised against anything? A company that says yes to everything either has an exceptional roof in front of it, or didn't look closely.
- Is the timeline realistic – including registration with the grid operator and the incentive application?
And one last point that often gets lost in consultations: ask who actually installs the system. There are differences between brokers, general contractors and the companies actually carrying out the work, when it comes to warranty and who to contact if there's a fault – the context is set out in Solar company Zurich: finding an installer and General contractor or specialist company?.
The most valuable twenty minutes of a consultation are almost never those on the roof – they're the ones at the kitchen table, when we ask what's planned for the next five years. That's when the sentence «the oil heating is getting on a bit too» or «our son's getting an EV soon» comes up, and suddenly we're talking about a different system size than ten minutes before. Conversely, we regularly advise against things owners had firmly planned – most often the battery as a first step, when the consumption profile doesn't yet support it. That's rarely what someone wants to hear, and almost always what they're glad about two years later. What we leave behind at the end is therefore never just a price: it's the assumptions that price was calculated with.
Frequently asked questions
Is a solar consultation free?
With an installation company, usually yes – it's part of preparing the quote and non-binding. Independent energy consultations without a sales interest bill on a time-and-materials basis. Municipal initial consultations are subsidised or free, depending on the municipality.
How long does a solar consultation take?
For a single-family home, count on one to two hours on site, including inspecting the roof and basement. The quote follows afterwards – from experience, within one to two weeks, depending on workload.
Do I need an independent consultation, or is the installer enough?
For a classic single-family home, the specialist company is enough, provided you compare two to three quotes. For apartment buildings, condominium ownership or a full renovation, an independent consultation can structure the decision beforehand – but it doesn't replace the quotes.
What do I need to have ready for the consultation?
Your last electricity bill, details about the roof and year built, and your plans for the coming years – heat pump, EV, renovation. These are the three pieces of information that most strongly influence system size and profitability.
Can a consultation also happen online or by phone?
For a ballpark figure, yes; for a quote, no. Roof structure, substructure, shading over the course of the day and the condition of the electrical installation can't be assessed remotely – and these are exactly the points that determine the cost.
Is the consultation really without obligation?
With reputable companies, yes: you receive a concept and a quote without signing anything. Pressure to sign during the consultation – «only valid today» – is one of the clear warning signs.
Free initial consultation
Consultation on site – free of charge and without obligation
We look at the roof, basement and consumption, and put a concept with individually itemised line items on the table for you. Including the points we advise against.
Want to calculate yourself first? Solar calculator with official roof data →
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Swissolar-certified specialist company · ESTI installation authorisation (Art. 14 NIV) · in Zurich since 2017 · over 150 systems completed · a personal answer from the specialist company, no call centre
Sources: ecoEn's consultation and quoting practice (Zurich region), offerings of cantonal and municipal energy consultation offices 2026, Swissolar recommendations on preparing quotes.
Last updated: 9 July 2026 · Author: ecoEn editorial team
