Removing a load-bearing wall

• a steel beam;
• a steel beam with columns;
• a steel portal frame;
• a composite steel structure;
• a lintel structure;
• an additional foundation provision.

This way your contractor knows in advance exactly which structure is needed and how it must be built safely.

When is a wall load-bearing?

A load-bearing wall is part of the main load-bearing structure of a building. The wall can carry loads from:

• upper floors;
• timber or concrete joist floors;
• walls above;
• roof structures;
• other structural components.

Whether a wall is actually load-bearing cannot be determined from the wall thickness alone. We assess, among other things:

• original building drawings;
• structural drawings;
• direction of the floor joists;
• position of the walls above;
• material and thickness of the wall;
• construction of the home;
• any previous renovations.

In case of doubt, additional investigation or an on-site survey may be necessary.

Why is a structural calculation needed?

When a load-bearing wall is removed, an existing support disappears. The loads that were originally transferred downwards through the wall must be redirected to a new structure. A structural engineer therefore determines:

1. which load rests on the existing wall;
2. which new span is created;
3. which steel section or other structure is needed;
4. which support reactions arise;
5. where these forces end up;
6. whether the existing walls and foundation can absorb these forces.

The width of the opening alone is therefore insufficient to determine which steel beam is needed.

Which structure replaces the load-bearing wall?

The right solution depends on the existing structure, the desired opening and the support possibilities.

Steel beam

For a relatively limited opening, a steel beam can often be placed directly on sufficiently strong masonry or concrete walls. Commonly used steel sections are, for example:

• HEA;
• HEB;
• IPE.

Which section is needed is determined by calculation. The strength of the beam is not the only factor. Deflection, bearing length, local compressive stress, stability, connections and fire-resistant cladding can also be relevant.

Steel portal frame for a large opening

When almost the entire wall is removed, there is often not enough masonry left to support a beam safely. In that case a steel portal frame may be needed. A steel portal frame usually consists of:

• a horizontal steel beam;
• one or two vertical columns;
• end plates or corner connections;
• base plates;
• fasteners;
• any foundation provisions.

The columns transfer large concentrated forces downwards. That is why it must always be investigated what is present beneath these columns. A structure is only complete when the load can be safely transferred down to the foundation.

From steel beam to foundation

When removing a load-bearing wall, we do not only look at the new beam. The full load path matters:

This is especially important when new columns are used. A column may, for example, land on an existing timber or concrete floor that was not originally designed for such a concentrated load. Additional measures may then be needed, such as:

• a supporting beam;
• a new column on the floor below;
• a concrete pad;
• a foundation beam;
• local reinforcement;
• an additional foundation pile.

Whether this is needed is determined per situation.

Partially removing a load-bearing wall

Not every renovation requires removing the wall entirely. You can, for example, create an opening for:

• a passage;
• double doors;
• a sliding door;
• an open-plan kitchen;
• a larger living room;
• a kitchen island with a passage.

Even with a partial opening it must be checked how much masonry is retained and whether it has enough capacity as a support. An opening of, for example, 1.20 metres requires a different solution than an opening of 4 or 5 metres.

Removing the load-bearing wall between kitchen and living room

One of the most common renovations is combining kitchen and living room. In older homes there is often a load-bearing wall between the two rooms on which the upper floor rests. Removing this wall creates a larger living space, but structurally the floor must be supported again. We assess, among other things:

• span direction of the floor;
• walls above;
• position of chimneys or flues;
• available support;
• desired clear height;
• the possibility of incorporating the beam into or below the ceiling.

Where possible, we look for a practical solution in which the steel structure can be integrated into the interior as efficiently as possible.

Removing a load-bearing rear façade for an extension

For an extension, a large part of the existing rear façade is often removed. Structurally this is usually more far-reaching than a normal internal wall opening. The rear façade may be loaded by:

• the upper floor;
• the façade above;
• the roof structure;
• masonry;
• stability forces.

For a wide rear-façade opening a steel portal frame is therefore regularly used. It must also be checked whether the foundation beneath the new columns is strong enough.

Removing a load-bearing wall in an apartment

In apartments, an opening requires extra attention. The structure of your home is part of a larger building. A load-bearing wall can carry loads from several floors above your apartment. The forces can therefore be considerably greater than in a single-family home. In addition, other parties may be involved, such as:

• the owners' association;
• the property manager;
• the municipality;
• the architect;
• the contractor;
• the structural engineer of the owners' association.

Depending on the deed of division and the house rules, the approval of the owners' association may also be required. A municipal permit does not replace any private-law approval from the owners' association.

Temporary support during the works

A load-bearing wall must not simply be removed before the structure above is safely supported. During the works, temporary support may be needed. This is usually done with props and temporary supporting beams. The exact method depends on:

• the load of the floor above;
• the number of storeys;
• the direction of the joist floor;
• the ground beneath the props;
• the sequence of work;
• the dimensions of the opening.

It must also be checked whether the floor on which the props stand can absorb the temporary load.

Propping plan for a load-bearing wall

In simple situations, a contractor can carry out the temporary support according to the structural starting points and usual construction methods. In more complex situations, a separate propping plan may be necessary or advisable. This indicates, for example:

• the position of the props;
• the centre-to-centre spacing;
• temporary supporting beams;
• the load transfer;
• support on the floors below;
• the execution sequence.

The principle is that the existing structure remains stable and safe throughout the renovation.

Structural calculation for the steel beam

For the permanent structure we calculate, among other things:

• permanent loads;
• imposed loads;
• loads from the walls above;
• floor load;
• roof load if relevant;
• bending moment;
• shear force;
• deflection;
• support reactions;
• column forces;
• connections where needed.

When renovating an existing structure, the structural safety is assessed within the applicable framework for existing buildings and renovations. The Dutch Building Decree (Bbl) refers to the NEN 8700 series for this. For the relevant loads, NEN 8701 is used in conjunction with NEN 8700 and the Eurocodes.

Structural drawing for the contractor

In addition to the calculation, we produce a clear structural drawing. It can indicate, among other things:

• the position of the new beam;
• the steel section;
• columns;
• the dimensions of the opening;
• supports;
• base plates;
• connections;
• bedding/grouting under supports;
• supporting structures;
• relevant cross-sections;
• structural notes.

This gives the contractor clear starting points for ordering and assembling the steel structure.

Permit for removing a load-bearing wall

Removing a load-bearing wall changes the load-bearing structure of the building. For the technical building activity, this is subject to a permit under the Bbl. The permit application may require, among other things:

• the existing floor plan;
• the new floor plan;
• the structural calculation;
• the structural drawing;
• details of the steel structure;
• additional information about the existing structure.

Depending on the building and the location, other rules or approvals may also be relevant, for example a listed building, a protected building or rules from the municipal environment plan. Via the Omgevingsloket (Dutch permit portal) you can check which activities and approvals apply to the specific address.

Why calculate first and demolish afterwards?

Sometimes a load-bearing wall is already partly removed before it is clear which structure will replace it. That entails unnecessary risks. A safe sequence is:

1. Investigate the existing structure. First we determine how the home is structurally built up.
2. Establish the desired opening. Together with the designer or client we determine the final dimensions.
3. Calculate the structure. Then the beam, columns and supports are calculated.
4. Determine temporary support. Before demolition it becomes clear how the existing structure is temporarily supported.
5. Install the new structure. Only then is the load-bearing wall removed in a controlled way and the permanent structure installed.

This approach reduces the risk of uncontrolled deformation, cracking or instability.

What information do we need?

For a first assessment we preferably receive:

• the address of the home;
• floor plans;
• original archive drawings;
• the desired width of the opening;
• photos of both sides of the wall;
• photos of the floor above and below if relevant;
• available structural drawings;
• a short description of the renovation.

Do you not have archive drawings? Then we can first assess which information is missing and whether an additional survey or investigation is needed.

Archive drawings and existing structure

For older homes, municipal archive drawings can provide a lot of information about:

• load-bearing walls;
• joist floors;
• concrete floors;
• steel structures;
• foundation;
• original layout.

But archive drawings are not always complete and the actual situation may have changed later. That is why important structural data is checked against the existing situation where necessary.

Our approach

1. First assessment. You send us the drawings, photos and desired situation. We assess which structural components are relevant.
2. Determining the load transfer. We investigate which floors, walls or roofs are carried by the wall.
3. Structural design. We design a suitable solution, for example a steel beam or portal frame.
4. Calculation. The structure is calculated and checked.
5. Structural drawing. We work out the design in a clear technical drawing.
6. Coordination. Where necessary, we coordinate the structure with the contractor, architect, steel fabricator or municipality.

Practical structural solutions

The heaviest structure is not automatically the best structure. We also consider the practical execution. Factors include, for example:

• desired ceiling height;
• available support;
• assembly of the steel;
• pipework;
• position of window/door frames;
• existing floor;
• accessibility of the building site;
• cost of steel and assembly.

Sometimes a lower steel section from a different section series is more practical. In other cases a portal frame is more efficient than a very heavy simply supported beam. The solution is therefore matched to both the calculation and the actual execution.

For general building advice or projects outside our structural specialism, we work together with Aboss Bouwadvies.

Frequently asked questions about removing a load-bearing wall