Price differences of several thousand francs for the same system are normal – and rarely due to the material. The four most common reasons: different scope of work, different assumptions about your roof and electrics, different equipment level, and the provider's structure. A quote that deviates significantly is therefore neither a stroke of luck nor a scandal, but something to check. (As of: July 2026)
Key points in brief
- The market dictates a range – within the guideline values of CHF 2,000–2,800 per kWp there's a lot of room for legitimate differences.
- The total sum only compares something if the same scope of work is behind it – and that's exactly where quotes differ most often.
- Anyone who quotes without a site visit is guessing at scaffolding, electrics and roof details – and the guessing goes in both directions.
- Part of the price is provider structure: company size, subcontractors, marketing, workload.
- Conspicuously cheap means: ask what's missing. Conspicuously expensive means: ask what's included.
How big are the differences really?
Anyone who gets three quotes for the same single-family home regularly experiences differences of 20 percent or more – for a 10 kWp system that's quickly several thousand francs. That's irritating, but at first it's only a sign that the guideline values per kWp are a range, not a fixed price: CHF 2,000–2,800 per kWp for typical single-family home systems, depending on size, roof and equipment (as of: July 2026).
A difference only becomes worrying when it can't be explained. And for that, you need to know where differences arise. It's almost always the same four places.
Reason 1: the scope of work isn't the same
The most common and mundane reason: the quotes don't contain the same thing. One includes scaffolding, electrical adaptations and all the registrations, the other outsources exactly these items – as «by others», as an assumption, or simply by omission – making it look cheaper as a result. The item still gets paid for, just later and as a surprise.
The remedy is comparing line items side by side: which blocks does each quote contain, which are missing, which are declared as exclusions? The cost line items of a complete quote are the yardstick for this. Rule of thumb from that reading: the prices may differ, the line items shouldn't.
Reason 2: the assumptions about your house differ
Two providers, two assessments of the same property. Anyone who has visited the roof knows whether the meter box from some 60 years ago needs replacing – from experience, the number-one cost factor among the ancillary works – and whether a road closure for the scaffolding will be needed on the narrow neighbourhood street. Anyone who quotes from an aerial photo makes assumptions. Optimistic assumptions produce low quotes and expensive supplementary bills; pessimistic ones produce high quotes with built-in reserve.
That's why every price difference should come with the question: what's this figure based on? A quote made after a site visit and one made from an online form are two different products, even if the same system size is written on them.
Reason 3: the equipment level is different
Within the market band there are three price classes: from the solid economy segment through the mid-range to the premium equipment level with in-roof appearance and extended service. Two quotes from different classes may differ significantly – they're offering different things. The comparison is still worthwhile: often the difference lies in items that bring no added value for your specific roof. How to distinguish real quality differences from labels is shown in the article Cheap vs. expensive.
Reason 4: the provider's structure
The last part of the difference has nothing to do with your roof. Companies calculate from different cost structures: their own installation teams or chains of subcontractors, a lean organisation or a sales force on commission, full order books or a lull. A low price is therefore neither a warning sign nor proof of quality – it's information about where savings are being made. This assessment, along with the question of when saving becomes risky, is explored further in the article Cut-price providers: where the low price comes from.
| Reason | How to recognise it | What to do |
|---|---|---|
| Scope of work | missing or outsourced items | Compare line items, have exclusions priced |
| Assumptions | Quote without a site visit, flat-rate electrics | ask what the figures are based on |
| Equipment | different component class, in-roof, service | check whether the added value fits your project |
| Provider structure | conspicuously low/high total price for the same content | Look at the service organisation and references |
Guidance, as of: July 2026. The individual quote including its description of services is binding.
How do you deal with quotes that deviate significantly?
Not with the middle one. The reflex to simply take the middle quote skips the real work: making the quotes comparable. The article Comparing quotes correctly describes the approach for that – the same system size, the same line items, price per kWp as the comparison figure.
After that, the same applies in both directions: if a quote is conspicuously far below the band, that's something to check – what's missing, what was assumed, who's installing? If one is conspicuously above it, likewise – which item justifies the surcharge, and do you need it? A reputable company answers both questions without dodging. Anyone who dodges has thereby given the answer too.
When prospective clients put comparison quotes on the table for us, the difference is almost never a mystery – after ten minutes of comparing line items, it's explained. Typically: the cheapest quote hasn't included scaffolding or meter-box replacement and was calculated from an aerial photo. If you add in the missing items, the gap shrinks to a few hundred francs – and suddenly it's no longer the price that decides, but who does the work cleanly.
Frequently asked questions
Are big price differences a sign of a disreputable market?
No. They reflect real differences in scope, assumptions and equipment – plus normal variation in cost structures. It only becomes disreputable when a provider can't or won't explain the difference.
Should I always question the cheapest quote – or also the most expensive?
Both, with the same question mirrored: what's missing here – or what's in here that I don't need? The best quote is rarely the cheapest, but the most complete one at a fair price.
How many quotes should I get?
Two to three with a site visit are more informative than five from an online form. From the fourth one onward, you're usually only comparing assumptions against assumptions.
Can I use the cheapest quote to push down the price of the others?
Negotiating is legitimate – but don't push out line items from the quote that you'll buy back later as a supplementary bill. Anyone who compares the price of a complete quote with an incomplete one is negotiating against themselves.
Why do some companies quote without a site visit?
Because it's fast and cheap – for the provider. For a first rough estimate, that can be enough; only a quote that has seen your roof, your electrics and your access is suitable as a basis for a contract.
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Sources: Quote and project practice of ecoEn GmbH, Zurich region (as of July 2026).
Last updated: 9 July 2026 · Author: ecoEn editorial team
