Feasibility and volume study in Switzerland: what private building owners need to know
- Simon Käslin
- Jan 4
- 14 min read
Updated: 1 hour ago
Summary
A feasibility and volume study in Switzerland clarifies early on whether a construction project on a specific plot of land in Switzerland is legally, technically and financially realistic. The volume study is often the design core of it and shows which building volume and which floor plan logic is plausible, usually in variants. Both create clarity before expensive decisions, reduce risks and prevent planning running too far in a direction that later turns out not to be permittable or not financeable.
Table of contents
What is the difference between a feasibility study and a volume study?
When is a feasibility and volume study in Switzerland particularly worthwhile?
What does a feasibility study or volume study cost in Switzerland?
Which building law aspects are particularly decisive in Switzerland?
Which technical and project-specific points will be checked?
How is the project roughly classified economically, and what could go wrong?
What are some typical mistakes that occur without a feasibility study or with a poor study?
How can you recognise a good feasibility study and how can a layperson assess it?
How can building owners get the most out of a feasibility study?
FAQ: Frequently asked questions from private building owners in Switzerland
Is your project truly feasible?
A feasibility study clarifies this before planning costs are wasted.
1. What is a feasibility study and what is a volume study?
A feasibility study is a structured preliminary assessment that answers one question: is the planned construction project feasible on this plot, and if so, under what conditions?
It does not only look at a design, it examines the most important factors that decide between success and failure. Typically this covers building law, the prospects of obtaining a building permit, technical feasibility, cost logic, risks and a realistic assessment of the next steps.
A volume study is in many cases the design component that shows which building mass is plausible on the plot. It often works with simple 3D massing models and sketched floor plans, so that it becomes visible how the possible volume translates into a spatial programme. Variants are frequently produced in order to compare utilisation, quality, circulation and cost impact.
At raumwert plus exactly this point is central: after the study, building owners should not have "more pictures" but more clarity. The results are therefore prepared so that decisions are possible: carry on, adapt or stop, and which clarifications are really worth doing.
2. What is the difference between a feasibility study and a volume study?
The difference is important for building owners because many offers on the market mix up the terms.
Volume study
The spatial question is in the foreground here: what could the project basically look like on the plot? Which massing is plausible, which siting makes sense, which floor plan logic works? It is about the building volume, the storeys, the circulation and the first functional relationships.
Typical elements are:
Massing and siting variants
rough floor plan diagrams
a short comparison of variants (quality, efficiency, risks)
Feasibility study
Here it is about the overall picture that is relevant to the decision. The volume study is often the core, but reality is added to it: building law, technical feasibility, cost logic, risks, dependencies and time frames.
Typical elements are:
assessment under building law (including the critical points)
volume and variants as the basis
rough cost and schedule logic
a list of risks and open issues
conclusion: feasible yes or no, and under what conditions
In practical terms this means: in simple situations a good volume study can already create a great deal of clarity. But as soon as building law, site servicing, budget, risk or the prospects of a permit are unclear, "volume alone" is often not enough. A worked feasibility study example on a real plot shows what this looks like in figures.
3. When is a feasibility and volume study in Switzerland particularly worthwhile?
In Switzerland this is worth doing very often, because rules and practice differ from municipality to municipality and because later corrections become expensive. A feasibility study is particularly useful whenever important decisions have to be taken and too many points are unclear.
Typical situations where a feasibility study is particularly useful:
Before buying the plot: it should be clear whether the target project really fits, ideally as part of a property analysis before purchase.
Unclear utilisation: utilisation ratio (AZ), building mass ratio (BMZ), floor space ratio (GFZ), site coverage ratio or special rules on how areas are counted.
Sloping sites: excavation pit, retaining walls, terrain reference, site servicing and cost risk.
Multi-family houses and investment properties: efficiency, ancillary areas, circulation cores, apartment types and marketability.
Townscape, protection, water bodies, hazard maps: as soon as a restriction is in play.
Easements and rights: rights of way, utility easements, rights to build closer to the boundary or missing access rights.
Time pressure: when the move-in date, the sale date or the financing is tight.
A feasibility study also makes sense when a plot already exists but the planning does not become "stable". The cause then often lies in a framework that was never cleanly clarified. This is exactly where raumwert plus often starts, with a site analysis: first clarify the framework, then build up variants properly, and only then move into the next phase.
4. What specific advantages do building owners have?
A feasibility study is not an end in itself. Its purpose is to provide concrete help, specifically to enable decisions to be made with less uncertainty.
4.1 Clear decision-making basis instead of gut feeling
This results in a comprehensible statement as to whether the project is fundamentally viable. Ideally, this should not be presented as vague text, but as a clear classification with conditions. For building owners, this is often the most important point: not "it could work," but "it works if…" or "it doesn't work because…".
4.2 Risk minimisation
Many costly problems arise because something fundamental is overlooked at the beginning.
Common examples include:
a regulation that limits the number of storeys or building height
parking requirements that eat up space or trigger an underground car park
site servicing that is not secured
Protective requirements that massively influence the design or material
Cost blocks that only become visible late in the game
A good study makes these points visible early on. This isn't dramatic; in fact, it's precisely the point.
4.3 Cost certainty at the right level
Not down to the last franc, but in such a way that budget, standards, and volume are aligned. A good feasibility study identifies cost drivers and points out uncertainties, instead of providing a false sense of precision.
4.4 Better planning through variants
Variants are not "playing around". They help to understand real conflicts of objectives, for example:
More space vs. better outdoor spaces
maximum utilisation vs. permit risk
more parking vs. better living quality
basement solutions vs. costs and excavation pit
4.5 Realistic timetable
Many building owners underestimate the processes and necessary assessments. A feasibility study provides a rough overview of what is realistic and identifies early dependencies. This prevents stress, replanning, and unrealistic expectations later on.
5. At what stage does this make sense and when is it too late?
The sooner, the better. The greatest benefit arises before binding decisions are made.
Suitable times:
before purchase or before concluding preliminary contracts
at the very beginning of the project, before a solution is determined
at the latest before expensive detailed planning, specialist planner iterations or the logic of the building application begins
If it only becomes visible after the building application that basic assumptions were wrong, it becomes expensive and slow. Many corrections set off chains: plans, structural design, building services, fire protection, costs, contracts and deadlines all hang together.
6. Who conducts a feasibility study or volume study, and what should building owners pay attention to when making their selection?
In practice these are usually produced by architects or architectural practices, sometimes supported by engineers or other specialists. What matters is less the title than whether design, building law, technical plausibility and cost logic are brought together.
What building owners should pay attention to:
6.1 Experience with local rules
Feasibility in Switzerland is highly dependent on the municipality. Those familiar with local practices can identify pitfalls more quickly and know which points are truly critical in preliminary assessments.
6.2 Ability to combine building law, design and economic efficiency
A strong design alone is not enough if the levers in building law are not properly examined or costs are ignored. Conversely, a pure "rule check" without usable design logic is often useless.
6.3 Interdisciplinary access
Depending on the project, additional clarifications may be necessary, for example:
geology and contaminated sites where there is a suspicion
Traffic and access
noise and emissions
special cases such as protection requirements or watercourse setbacks
6.4 Independence and honesty
A thorough feasibility study can also lead to a "stop" decision. This is often the greatest benefit, because it prevents costly mistakes.
At raumwert plus this "stop or change of course" is explicitly part of the work: if the fundamentals are not right, that is made visible early and options are shown, instead of turning unnecessary planning loops.
7. What does a feasibility study or volume study cost in Switzerland?
Costs depend heavily on project size, complexity and scope of services. So that building owners have clear guidance, here are realistic possible costs in CHF (as an order of magnitude; depending on the case it can be below or above this).
7.1 Guideline values in figures (CHF)
Project type / Scope of services | Typical cost range (CHF) | What is typically included |
Volume study, single-family house | 2,000 to 15,000 | 1 to 2 variants, massing logic, simple floor plan diagrams, short comparison of variants |
Feasibility study, single-family house | 2,000 to 15,000 | Assessment under building law, volume and variants, rough cost logic, risks and open issues, next step |
Volume study, multi-family house | 4,000 to 40,000+ | Variants, apartment type logic, circulation, overview of ancillary areas, efficiency view |
Feasibility study, multi-family house | 4,000 to 40,000+ | Building law, variants, cost logic, risk analysis, dependency topics, rough programme logic |
7.2 Why this bandwidth is so large
The price is primarily determined by the effort involved. The biggest drivers are:
Number of variants and iteration loops
complexity of the requirements (special land use plans, protection requirements, terrain)
parking and basement levels (often major cost drivers)
whether preliminary inquiries with authorities should be integrated
Data situation and document quality
whether a rough cost logic is merely made plausible or derived in a structured manner
7.3 How to meaningfully compare offers
Price alone says little. Building owners should ask specifically about the output:
Are there variants or just a sketch?
Is there a clear list of risks and open issues?
Is there a comprehensible cost logic or just a single sum?
Is there a clear conclusion with conditions?
If these four points are answered clearly, the result is usually a study that really makes a difference.
8. What content must a good feasibility study cover?
A good feasibility study is not a nice PDF without consequences. It has to be structured so that decisions are possible.
Typical content that really helps:
Building law analysis: zone, key figures, setbacks, heights, parking, special rules
Volume and variant study: massing, siting, number of storeys, circulation, floor plan logic
Technical feasibility: site servicing, terrain, building plot, excavation pit, construction site logistics
Rough cost estimate: cost drivers, uncertainties, plausibility check
Prospects of a building permit: assessment of chances, risks and dependencies
List of risks and open issues: what has to be clarified before the building application
Rough programme: milestones, critical clarifications, duration of the procedures
Conclusion: is it feasible, yes or no, and which conditions apply?
This is how raumwert plus typically works in such studies: first the hard framework (building law, building plot), then variants, then cost logic and risks, and at the end a conclusion that can be used as the basis for deciding the next steps.
9. Which building law aspects are particularly decisive in Switzerland?
This is where most problems arise in practice. And this is where municipalities differ significantly. Many problems don't occur because "the property is bad," but because individual rules were misunderstood or checked too late.
Important building law topics:
9.1 Zone and use
Does the project comply with the zoning? Are there restrictions in the building and zoning regulations (BZO) or in special land use plans? For multi-family houses in particular this is often the first hard filter.
9.2 Utilisation and key figures
Depending on the municipality, the utilisation ratio (AZ), the building mass ratio (BMZ), the floor space ratio (GFZ), the site coverage ratio or other key figures apply. What matters is:
how areas are counted
whether ancillary areas, stairs, plant rooms, balconies, conservatories and basement areas count differently
whether bonus schemes exist or restrictions apply
9.3 Setbacks, heights, storeys, building lines
This sounds trivial, but it is often the limiting factor:
boundary setbacks and distances between buildings
maximum building and ridge height
number of storeys, roof shape requirements
building lines or reserved lines (for example for road space or water bodies)
9.4 Parking and site servicing
Parking requirements often trigger major consequences:
More parking spaces than expected
loss of space in the outdoor areas
an underground car park as a cost driver where there is no other solution
Access width, turning areas, gradients
9.5 Townscape and protection
When local heritage protection regulations, listed buildings, or other protective requirements come into play, the design and materials often change significantly. A feasibility study must identify this early on; otherwise, the planning will be unrealistic.
9.6 Water bodies, hazard maps, environment
Setbacks from water bodies, flood hazards, landslides, noise zones and further requirements influence the building plot and the costs.
10. Which technical and project-specific points will be checked?
A feasibility study must examine technical issues to such an extent that it becomes clear whether the project will be fundamentally difficult or expensive. It is not about detailed dimensions, but about plausibility and risks.
Typical points:
site servicing with water, waste water, electricity and communications
Access and construction site logistics
Terrain, excavation pit, retaining walls, embankments on slopes
plausible structural principle (not calculated, but logical)
plant areas and ancillary rooms of a plausible size
for multi-family houses: circulation core, shafts, escape routes, ancillary area logic
Honesty is crucial: If a point cannot be assessed without further clarification, this must be clearly stated in the study, including a suggestion on how to close it.
11. How is the project roughly classified economically, and what could go wrong?
Building owners want to know early on whether it works financially. That is legitimate. But this is exactly where the biggest misunderstandings arise, because at the beginning the figures are often too optimistic or important topics are missing.
A meaningful economic classification includes:
Rough cost estimates with clear assumptions about standard, complexity and ancillary areas
making the cost drivers visible (slope, basement, parking, building envelope, fit-out)
Identification of uncertainties (e.g. soil conditions, protective requirements, development)
a statement on how robust the estimate is (a range instead of false precision)
What often goes wrong:
Costs are omitted or presented too optimistically.
Additional costs and dependencies are missing.
A project seems "feasible" until parking costs or slope costs throw everything off balance.
in multi-family housing, ancillary areas and circulation are underestimated, so efficiency looks better than it is
Especially with investment properties it helps if the study does not only show an area but also explains how the rentable area comes about and where efficiency is lost. That is a typical lever from the project optimisation practice of raumwert plus.
12. What are some typical mistakes that occur without a feasibility study or with a poor study?
These are the classics from practice:
It starts with a nice design, but without sound building law logic.
People rely on verbal statements instead of documented clarifications.
Parking and site servicing are taken seriously too late.
Costs are assessed too late; by then, many decisions have already been made.
Risks such as easements or protective requirements only emerge during the proceedings.
Detailed planning begins too early, before it is clear whether the basic concept is stable.
Without a thorough preliminary review, building applications can be rejected, delays occur, plans need to be redesigned, and unnecessary additional expert opinions are required. This costs time and money, and it creates uncertainty for everyone involved.
13. How can you recognise a good feasibility study and how can a layperson assess it?
Building owners do not need to know standards by heart in order to recognise quality. A few clear criteria are enough.
13.1 Transparent assumptions
A good study shows which assumptions were made and why. Example: how was the utilisation calculated? Which areas were counted and how?
13.2 Clear separation of facts, interpretation and open questions
Facts: regulations, key figures, hard requirements.
Interpretation: assessment of the prospects of a permit, evaluation of variants.
Open: points that are not certain without further clarification.
13.3 Variants with a comprehensible comparison
Not just “Variant A and B”, but explained:
why A is better or worse
what risks and cost implications arise
which variant better meets the goals
13.4 Clear conclusion
At the end it must say whether it is feasible, and if so under what conditions. No soft soap.
13.5 A sensible level of detail
Too superficial does not help. Too detailed is often unnecessarily expensive. The right level of detail is: enough to decide properly.
14. How can building owners get the most out of a feasibility study?
Here are the points that make the most difference in practice:
14.1 Clearly formulate goals
It is worthwhile to briefly define the project beforehand:
single-family house or multi-family house, rough order of magnitude
Standard and budget framework
desired timetable
Mandatory criteria (e.g. number of rooms, underground parking yes/no, barrier-free access)
The clearer the goal, the more targeted the study.
14.2 Compiling documents
The following are helpful:
Land register extract, cadastral map, parcel number
known easements and rights
photos, existing plans, information on utility lines
If available: previous projects or preliminary inquiries
14.3 Allowing variants
At least where genuine conflicts of objectives exist. Without alternatives, it is often just an opinion, not a basis for decision-making.
14.4 Close open issues early
It's worthwhile to explicitly ask about the two or three biggest uncertainties. And then: How will they be resolved? Who will resolve them? By when?
14.5 Use the result strategically
A thorough feasibility study is also helpful outside of the planning phase:
Discussions with bank or financing
decisions when buying a plot
better task definition for the next phase
clear communication with partners and stakeholders
At raumwert plus a very simple principle is often used: after the study, building owners should be able to say in three sentences what is possible, what is critical and what has to happen next. If that does not work, the study was not clear enough.
15. Practical examples
15.1 Townscape protection forces an adaptation and the project becomes permittable
A modern concept with a flat roof looks convincing, but fails on the protection requirements. The feasibility study recognises this early and develops a variant that fits local practice. Result: a solution capable of obtaining a permit, instead of a costly redesign after submission.
15.2 Sloping plot: site servicing and excavation pit make it economically unreasonable
The study shows that retaining walls, the excavation pit and the access road trigger enormous costs. Result: the project is stopped early or moved to another plot. In the best case that saves a great deal of money and time.
15.3 The programme becomes realistic, which means less stress and fewer additional costs
Building owners plan with a desired date. The study places procedures, clarifications and construction time on a realistic footing. Result: less time pressure, fewer expensive interim solutions.
15.4 Negative example without a preliminary review
Without feasibility logic there are no clear area allocations, costs stay unclear, and the project runs into delay and redesign. Result: more effort under time pressure, which is exactly what an early study is meant to avoid.
16. FAQ: Frequently asked questions from private building owners in Switzerland
16.1 Do private building owners really need a feasibility study for a single-family house?
If the plot and the rules are clear, a focused volume study is sometimes enough. But as soon as utilisation, setbacks, parking, slope, protection or budget questions are uncertain, a feasibility study quickly pays off.
16.2 Is a feasibility study already a preliminary design?
No. It sits before the preliminary design and is meant to clarify the fundamentals so that the preliminary design can be stable and focused.
16.3 Can't you check this yourself, look at the zoning plan and do the calculations?
Part of it you can do yourself. In practice it often fails on the details of how areas are counted, on special rules and on local interpretation. That is exactly where the big problems arise later.
16.4 How many variants are sensible?
For single-family houses, 1 to 2 variants are often enough if the question is clear. For multi-family houses, variants are usually central, because circulation, efficiency, apartment types and parking are strongly linked.
16.5 What is the most important result that should be there at the end?
A clear conclusion with conditions: is it feasible, yes or no? What are the biggest risks? What are the next steps so that the project can move ahead safely?
16.6 What does a feasibility study or volume study cost?
This depends on project size, complexity and scope of services. As an order of magnitude, volume and feasibility studies cost around CHF 2,000 to 15,000 for a single-family house and around CHF 4,000 to 40,000 and more for a multi-family house. When comparing offers, the output counts for more than the price: variants, a clear list of risks and open issues, a comprehensible cost logic and a clear next step.
Is your project truly feasible?
A feasibility study clarifies this before planning costs are wasted.
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