Bathroom renovation:
Key steps and mistakes to avoid
Renovating a bathroom is often perceived as a quick and relatively simple project.
In reality, this is one of the most technically sensitive types of renovation in housing , particularly in Geneva and the canton of Vaud, where buildings are dense, often old and subject to strict regulatory constraints.
Most problems encountered during a bathroom renovation do not stem from the choice of finishes or style. They most often result from poor sequencing, decisions made too late, and an underestimation of technical interdependencies .
This article presents the key steps of a bathroom renovation , the most frequent mistakes , and the essential points to anticipate for a successful project in French-speaking Switzerland.
Table of Contents
Why a bathroom renovation is technically complex
A bathroom concentrates several critical technical systems in a small area:
distribution of cold and hot water,
- internal plumbing and wastewater drainage,
heating,
ventilation and humidity management,
electricity and safety zones,
Waterproofing and finishing supports.
Unlike other parts, tolerances are very low and many decisions become irreversible once work has begun.
In Geneva and Vaud, the complexity is often accentuated by:
the limited thickness of the slabs,
the presence of shared technical risers in the building
acoustic and fire-resistant requirements,
undocumented ancient transformations,
the heating system to consider,
the potential presence of asbestos in various materials.
This complexity is also found in comprehensive renovation projects.
Key steps in a bathroom renovation (overview)
1. Analysis of the current situation and feasibility
Before making any design decisions, it is essential to identify:
the existing drainage routes and their slopes,
slab penetrations and structural constraints,
the actual ventilation possibilities,
electrical capacity and protection zones.
Neglecting this step almost always leads to late compromises.
2. Technical implementation and decision locking
This phase allows us to define precisely:
the possible placement of sanitary fixtures,
the alignment of the evacuations,
the type of heating (radiator, underfloor heating),
the ventilation strategy.
Many project owners underestimate how early these decisions need to be made. Once the slab or network work is completed, modifications become costly, or even impossible.
3. Infrastructure works (technical packages)
Plumbing, heating, ventilation and electricity must be coordinated as a single system .
Mistakes made at this stage often remain invisible until the finishing touches are applied, at which point any correction becomes intrusive.
4. Sealing, supports and controls
Waterproofing is not a finishing touch. It is a complete technical system in its own right , which must be:
continuous,
compatible with the chosen materials,
checked and tested.
The checks must absolutely take place before the walls are closed and the tiles are laid .
5. Finishes, equipment and commissioning
Only after complete validation of the networks and waterproofing can the following be installed:
tiles and natural stone,
sanitary fixtures
taps and accessories.
The final commissioning allows verification of the proper functioning of the ventilation, drainage and heating systems.
These constraints are also common in kitchen renovation projects.
Common mistakes in bathroom renovation
Validating the site layout without verifying the feasibility of the evacuations
A common mistake in apartments, especially when slopes or slab thickness are limited.
Choosing equipment too late
The depth of recessed tap fittings, support frames or shower systems directly impacts the thickness of the walls.
Close the walls before the full tests.
A leak detected after the tiles have been laid often results in partial demolition and additional costs and delays.
Underestimating ventilation
Insufficient ventilation promotes condensation, mold growth, and premature degradation of materials.
Consider the bathroom as a finishing project.
The majority of problems originate from invisible elements located behind the coatings.
Decisions to be made sooner than expected
In successful projects, the following elements are defined very early on:
Specific models of sanitary fixtures
shower type and drainage system,
thickness of the tiles or stone,
heating integration,
ventilation diagram.
Early clarity limits rework, delays and additional costs.
Bathroom renovation in an occupied building
In Geneva and Vaud, many bathroom renovations are carried out while the dwelling remains occupied.
This implies:
temporary sanitary solutions,
a precise phasing of the water cuts,
strict management of nuisances and security.
Even a small project then becomes technically more complex.
Why planning and coordination take precedence over speed
Bathroom renovations fail when approached as a linear succession of trades.
They succeed when:
The decisions are made in the correct order.
- Material supply lead times are planned with a safety margin.
Irreversible actions are deferred until validated.
Coordination precedes execution.
The goal is not to go fast, but to guarantee predictability and sustainability .
For complex projects, this role is formalized by an independent project management team.
Questions. Answers.
FAQ
Frequently Asked Questions
If you can't find the answer to your question in our FAQs, please feel free to contact us directly.
How long does a bathroom renovation take in Switzerland?
On average, a bathroom renovation takes between 3 and 6 weeks, depending on the complexity, the existing condition and the site constraints.
Is a bathroom renovation a complex project?
Yes. It concentrates several technical batches in a confined space, with little tolerance for sequencing errors.
What are the main causes of delays?
Late decisions, hidden constraints, and the lack of intermediate controls are the most frequent causes.
Is it possible to renovate a bathroom while remaining in the same dwelling?
Yes, provided there is rigorous planning and appropriate temporary solutions.
Do you need permits to renovate a bathroom in Geneva or Vaud?
Depending on the scope of the work and the type of building, permits or co-ownership agreements may be required.
In accordance with SIA best practices & Swiss standards
Current professional insurance
Bilingual support (FR / EN)
About Collet Homes
Choosing Collet Homes means entrusting your project to a team that takes full responsibility for the execution. Thanks to solid field expertise, rigorous coordination of stakeholders and an ability to anticipate and resolve technical issues, we guarantee a faithful, controlled and sustainable implementation.
Collet Homes is driven by two complementary influences: a Canadian approach of early involvement and teamwork, and the exacting Swiss standards of detail, structure, and performance. These two pillars guide how we think, collaborate, and build.
Each renovation is approached with technical curiosity, a sense of responsibility and the constant concern to deliver sustainable spaces, controlled and faithful to the vision of our customers.
To carry out renovation projects with high standards, clarity and responsibility, providing a reassuring structure, rigorous coordination and reliable technical expertise at each stage.
At Collet Homes, our mission is to protect the vision, investment and serenity of our clients and architectural collaborations, delivering sustainable, controlled spaces that are true to expectations.
To raise the standards of residential renovation in French-speaking Switzerland in the long term, by making clarity, collaboration and excellence in execution the standard.
We aspire to be a reference partner for demanding clients and architects, recognized for its ability to transform well-developed intentions into high-end and coherent spaces.
