Interior demolition: permits and asbestos, what to know before you start

Knocking down a partition wall, opening a kitchen onto the living room, removing a suspended ceiling or stripping an old floor: interior demolition seems simple, but it raises two questions that are best settled before the first swing of the sledgehammer. Is a permit needed, and does the building contain asbestos?

This guide is aimed at owners, co-ownership communities, tenants who have their landlord’s consent and small businesses. It explains the order of the steps, the points to watch and how to prepare a quote request to contractors in western Switzerland.

Interior demolition: what exactly does it cover?

The term covers all stripping-out and opening-up work inside a building, without touching its exterior envelope. The most common cases:

• knocking down non-load-bearing partition walls;
• opening up or removing a wall, which may be load-bearing;
• removing suspended ceilings, tiles, parquet or glued floor coverings;
• taking out a kitchen or a bathroom before renovation;
• chipping off plaster, screeds or wall tiles.

These operations almost always come before another job: masonry, laying new floors, or a full apartment renovation. Entrusting them to an interior demolition contractor makes it possible to coordinate what follows without losing time or damaging what must be kept.

Asbestos before demolition: why the age of the building matters

Asbestos was used for a long time in construction for its resistance to fire and heat. Depending on the period and the building, it can be found in tile adhesives, floor tiles, plasters, boards, pipe insulation or joints. As long as it remains intact and enclosed in the material, the risk is limited. It is the work that releases it: you drill, break or sand, and fibres end up in the air.

This is why, in a building constructed before 1990, an asbestos survey is required before work that affects the materials. The rules of Suva and those of the cantons frame this obligation. The precise arrangements (who must commission the survey, when, for which work) may vary: ask the municipality or the relevant cantonal department before signing anything.

What the survey provides

A survey consists of identifying suspect materials, taking samples and having them analysed. The report tells you whether asbestos is present, where, and in what form. It is then used for three things:

1. knowing whether the work can go ahead as normal or whether asbestos removal must come first;
2. describing the site accurately to the contractors who will prepare a quote;
3. protecting workers, occupants and neighbours.

A building constructed after 1990 is not entirely free of doubt, but the survey requirement does not arise in the same terms. If you are unsure about the year of construction or about earlier renovations, the safest course is to ask the municipality.

What to do if a material looks suspect

Stop everything. Do not scrape, do not drill, do not vacuum the dust with a household vacuum cleaner. Airing the room widely does not solve anything: the priority is not to spread the fibres further. Have the survey carried out, then follow its conclusions.

Asbestos removal: a job for a recognised company

If the survey reveals asbestos in the areas to be demolished, the removal must be entrusted to a company recognised by Suva. This is not a DIY job, even for a small area. The company sets up containment, protects its teams, works with a method suited to the type of material and disposes of the waste through a specific route.

A practical point: asbestos removal comes before ordinary demolition, never during it. This changes the order of the site and therefore its organisation. Inform all the contractors involved, including those who will come afterwards, so that they adjust their schedule to yours.

Load-bearing wall: an engineer’s opinion first

Not all partition walls are equal. Some simply separate two rooms; others carry the weight of the upper floors or the roof. Demolishing a load-bearing wall requires an engineer. They examine the structure, calculate the loads and define how to transfer them elsewhere, for example with a beam and supports. The masonry contractor then carries out what the engineer has specified, with the necessary temporary propping during the work.

A few useful habits:

• never assume a wall is non-load-bearing because it is thin or because a neighbour did the same in their home;
• in a co-owned building, a wall may be part of the shared structure: inform the managing agent or the owners’ meeting before going any further;
• keep the engineer’s opinion in writing; contractors will ask for it and, where applicable, so will the municipality.

Demolition permit: to be checked with the municipality

The question of the permit has no single answer in western Switzerland. Depending on the canton, the municipality, the nature of the work and the status of the building, a simple notification may be enough, a formal application may be required, or nothing in particular. Work that affects the structure, the use of the premises or a protected building is generally what calls for the most paperwork.

The only safe step: contact the municipality or the relevant cantonal department before the work, describe exactly what you are planning, and ask in writing what is required. A reputable contractor will in any case ask you the question before giving a price.

Tenant or co-owner: who must give consent?

• Tenant: the landlord’s written consent is essential for any change to walls, floors or ceilings.
• Co-owner: check the co-ownership rules and inform the managing agent, especially if the wall affects the structure or the common areas.
• Owner of a detached house: the decision is yours, but municipal and cantonal rules still apply.

Sorting and disposing of site waste

Demolition produces a lot of material, and it does not all go into the same skip. Site waste must be sorted and then disposed of according to its type: mineral rubble, timber, metals, plaster, plastics, possibly polluted materials. Asbestos-containing materials, for their part, follow a separate route, handled by the asbestos removal company.

When comparing quotes, check that sorting and removal are clearly included. A quote that leaves this item out holds a surprise for you when the final invoice arrives. Also ask who supplies the skips and who deals with access: stairs, lift, courtyard, parking for the lorry.

How a well-prepared interior demolition project runs

1. Define the project: which rooms, which elements, and what is to be done afterwards.
2. Check the age of the building and, if it dates from before 1990, commission the asbestos survey.
3. Have the walls concerned examined by an engineer if any of them may be load-bearing.
4. Contact the municipality or the cantonal department to find out whether a permit or a notification is required.
5. Obtain consent from the landlord, the co-ownership community or the neighbours if necessary.
6. Request several quotes, enclosing the survey report and the engineer’s opinion.
7. Plan the order of operations: asbestos removal, demolition, masonry, then finishing.

What makes the cost of interior demolition vary

No reliable price can be given without a visit. The main factors are:

• the surface area and volume to be demolished;
• the nature of the materials (light partition, concrete, glued tiles, screed);
• the presence or absence of asbestos, which adds specialist removal;
• site accessibility and the distance for removing waste;
• sorting, transport and disposal through the proper routes;
• the protection to provide for the parts being kept and for the neighbours;
• propping and structural reinforcement work if a load-bearing wall is involved;
• the schedule and the time restrictions within the building.

It is the quote, drawn up after a visit, that makes these elements concrete. Compare them line by line rather than on the total.

Common mistakes to avoid

• Starting before the survey in an older building: there is no going back once the fibres have spread.
• Assuming a wall is not load-bearing and opening it without an engineer’s opinion.
• Forgetting the municipality: a site started without checking can be stopped.
• Underestimating the waste: the quote must include sorting and removal.
• Doing work that involves asbestos yourself, even on a small area.
• Neglecting the consent of the landlord or the co-ownership community.

When to call a professional

As soon as the building dates from before 1990, as soon as a wall might be load-bearing, as soon as the demolition affects pipes, ducts or materials whose nature you do not know: turning to professionals is no longer a convenience but a precaution. For a light partition wall in a recent building, a demolition contractor can step in quickly once the local rules have been checked. For everything else, the order is: survey, engineer, permit if needed, then the work itself.

Requesting quotes in western Switzerland

To receive comparable proposals, describe your project as precisely as possible: location, type of building and year of construction, rooms concerned, presence of a potentially load-bearing wall, whether an asbestos survey is available, and the work planned after the demolition. You can request a quote online: your request is passed on to craftspeople and companies in the region, who will contact you to prepare a free, no-obligation quote. The site is not a building contractor and does not carry out any work itself.

Depending on your project, these pages may also help: interior demolition, masonry for openings and wall repairs, and apartment renovation if the demolition is part of a larger project.