Opening a load-bearing wall: IPN or HEB beam, a guide for western Switzerland

Opening a load-bearing wall to enlarge a living room or to link the kitchen to the living space is one of the most common renovation projects, and one of the most delicate. The wall carries part of the weight of the building: removing it without precautions endangers the structure.

This guide explains how to go about it in western Switzerland: how to recognise a load-bearing wall, what role the IPN or HEB beam plays, which procedures to plan for and how to choose the people involved.

Load-bearing wall or partition: the first check before any project in Lausanne, Geneva or elsewhere

A partition separates two rooms but does not carry the loads of the building. A load-bearing wall, by contrast, transmits the weight of the floors, the roof or the upper storeys down to the foundations. On paper the distinction looks simple; on site, it cannot be guessed by eye.

A few clues can offer guidance, but never suffice on their own:

• the original plans of the building, if they exist, often show the structural walls;
• a wall that continues identically from one floor to the next is more often load-bearing;
• a wall in the middle of the building, under a beam or a ridge, deserves particular attention;
• a wall that sounds hollow is not necessarily a partition: some constructions combine several materials.

Do not rely on thickness alone, nor on the visible material. If in doubt, treat the wall as load-bearing until a civil engineer or an architect has confirmed its role.

The civil engineer’s calculation: the condition for any opening

A load-bearing wall may only be opened after a calculation by a civil engineer. The engineer determines the loads to be carried and the span of the opening, then sizes the replacement beam and the temporary propping during the works.

This calculation is not a formality: it sets the section of the beam, the way it bears on the remaining parts of the wall and any reinforcement needed at the supports. It also gives tradespeople the basis for a reliable quote and the authority the basis for assessing a permit application.

Always ask for a written document, which you should keep with the property file. It will be useful in the event of a sale, an inspection or an insurance claim.

IPN beam, HEB beam or concrete: understanding the choice

Once the wall is removed, a beam carries the loads above the opening. Three solutions are common.

The IPN section

The IPN is a steel section shaped like an “I”, with relatively narrow flanges. It is valued when the available thickness is limited or when a discreet beam is wanted. It is often found in renovation work.

The HEB section

The HEB is also a steel section, shaped like an “H”. Its wider flanges give it a more generous bearing surface and good rigidity. It is often chosen when loads are heavy or when a wider bearing on the masonry is wanted.

The concrete beam

A reinforced concrete beam is another option, depending on the layout, access and constraints of the building. It requires formwork, reinforcement and curing time before the props can be removed.

The choice between these solutions is not made on personal preference or on what a tradesperson is used to installing. It follows from the engineer’s calculation, the span, the loads and the site constraints. Once the beam is chosen, its fire protection and casing must also be planned: a plasterer or a painter will then carry out the finishing.

Building permit, municipality and canton: what to check

Altering the structure of a building often falls under a permit procedure. A building permit is frequently required to open a load-bearing wall, but the rules vary by municipality and canton, and by the scale of the work.

Before any demolition:

1. contact your municipality’s building department or the competent cantonal office;
2. ask whether the opening requires a permit, and in what form (full application or simplified procedure);
3. find out which documents must be supplied, which generally include plans and the structural calculation;
4. wait for the decision before starting the works.

Starting without a permit when one is required exposes you to a stop-work order and reinstatement costs. Assume nothing: only the local authority can say what applies to your property.

An architect can prepare the file, draw up the project and coordinate the engineer and the contractors, which relieves the owner of the administrative side.

Co-owned apartment: the community’s agreement

In an apartment building, the wall you want to open rarely belongs to you alone. A load-bearing wall is part of the structure of the building, so opening it concerns all the co-owners.

The agreement of the co-ownership is required. In practice:

• inform the manager or the community of co-owners early;
• attach the engineer’s calculation and a description of the works;
• ask for the decision in writing, along with any conditions (working hours, protection of common areas, insurance);
• check the co-ownership regulations, which may govern building work.

As a tenant, you cannot undertake anything without the landlord’s agreement, and a load-bearing wall cannot be touched in a rented home without a decision from the owner and, often, a permit.

The stages of a load-bearing wall opening

Although each project has its own particularities, the logic is the same.

1. Diagnosis. The wall is confirmed as load-bearing, what it contains (ducts, pipes, electrical cables) is identified and the condition of the building is observed.
2. Engineer’s calculation. Sizing of the beam and the propping.
3. Procedures. Any permit from the municipality or canton, agreement of the co-ownership or the landlord.
4. Choice of contractors and quotes. Comparison of several offers based on the same calculation.
5. Site preparation. Protection of floors and furniture, removal of coverings, relocation of services in the area.
6. Propping. Temporary props carry the loads before the wall is touched.
7. Opening and installation of the beam. The wall is cut in sections, and the beam is put in place and wedged on its supports.
8. Transfer of loads and removal of the props. Only once the beam is working as intended.
9. Finishes. Plaster, protection of the beam, paint, floors.

Careful interior demolition limits dust and damage to neighbouring rooms. Installing the beam, reworking the supports and any filling-in are the job of masonry.

Who does what: engineer, architect, mason

Several trades share such a site, and it is best to know which one answers which question.

• The civil engineer calculates, sizes and specifies the propping. Without the engineer, no works.
• The architect designs the project, prepares the permit file and can supervise the works.
• The mason carries out the opening, installs the beam and reworks the supports.
• The interior demolition company can remove non-structural elements and clear the rubble.
• The secondary trades (electrician, plumber, heating engineer, plasterer, painter) come in if services run through the wall or for the finishes.

Ask each contractor to specify what is included in their offer: rubble removal, site protection, casing of the beam, reinstatement of floors. Omissions are often paid for afterwards.

Mistakes to avoid before opening a wall

• Starting without a calculation. This is the most serious mistake: no opening is decided “by eye”.
• Confusing a partition with a load-bearing wall. Removing one more partition costs nothing, while a load-bearing wall removed badly costs a great deal.
• Relying on a quote without a technical document. A price given without a calculation rests on assumptions.
• Forgetting the services. Electricity, water, heating or ventilation may run through the wall.
• Neglecting the permit or the co-ownership’s agreement. The consequences can be a stopped site or reinstatement.
• Removing the props too early. They are only taken down once the beam is in place and wedged.
• Planning nothing for the finish. An exposed beam, a plaster return or a floor repair should be planned from the start.

What makes the cost of opening a load-bearing wall vary

No serious price can be given without a visit and a calculation. Several factors weigh on the budget:

• the length of the opening and the loads to be carried, which determine the size of the beam;
• the type of beam: IPN section, HEB or concrete, with the associated work;
• the propping, more or less complex depending on the height, the storeys above and the condition of the building;
• site access: floor level, lift, narrow staircase, rubble removal;
• the services to be diverted or protected;
• the fees of the engineer and, where applicable, of the architect;
• file and permit fees;
• the finishes: casing or protection of the beam, plaster, floors, paint.

To compare, ask each company for a detailed quote based on the same calculation, with the precise scope of services. A shorter quote is not necessarily better value if it leaves out rubble removal or finishes.

When to call a professional, and how to start your request

For a load-bearing wall, the answer is simple: always. This is not a DIY job. The calculation is for a civil engineer, the execution for a competent company, and the procedures must be checked with the municipality or the cantonal office.

To prepare your request, gather:

• the address and type of property (house, apartment, co-owned building);
• the plans or photos of the wall concerned;
• the approximate size of the opening you want;
• your expectations for the finish and, if you know them, your scheduling constraints.

You can then request a quote: describe your project online, your request is passed to tradespeople and companies in the region, who contact you to prepare a free, no-obligation quote. Sos-travaux.ch is a neutral matchmaking service: it does not employ tradespeople and does not choose for you. It is up to you to compare the offers, ask your questions about the calculation, the propping and the finishes, and to sign only once the technical and administrative framework is clear.