Removing an internal wall is one of the most common ways homeowners create open-plan living. It can make a house feel larger, lighter and more connected. However, not every wall can simply be taken out.

Some walls carry roof, ceiling or floor loads. Some walls provide bracing against wind and earthquake loads. Some walls contain services, fire separation, or other building elements that need to be considered before work starts.

The safest approach is to check whether the wall is load-bearing, whether it is part of the bracing system, and whether engineering design or building consent is required.

Why internal walls matter structurally

In many New Zealand homes, internal walls do more than divide rooms. They may support ceiling joists, rafters, trusses, upper floors or other framing. They may also be lined with bracing plasterboard or connected into bracing lines that help the house resist wind and earthquake forces.

Removing a load-bearing wall without replacing the support can create sagging ceilings, cracking, movement and unsafe load paths. Removing a bracing wall without replacing the bracing can reduce the lateral strength of the house, especially in open-plan renovations.

When an engineer is usually needed

Engineering input is commonly needed where a wall is load-bearing, where a wall contains bracing, where a large opening is proposed, where a beam is needed, where posts or foundations need to be designed, or where council requires a PS1 or supporting calculations.

The engineer will consider where the load currently goes, how it can be transferred safely after the wall is removed, whether a steel, timber, LVL or glulam beam is appropriate, and whether new posts, lintels, footings or bracing elements are needed.

Building consent and wall removal

Some minor internal wall alterations may be exempt from building consent. However, MBIE guidance notes that internal walls often contain bracing elements, and some are load-bearing. Altering or removing these walls may reduce the building’s structural performance and is not covered by the simple exemption.

If the wall is load-bearing, bracing, fire-rated, masonry, or part of a more involved alteration, building consent may be required. It is better to confirm this before demolition begins rather than trying to resolve it after the work has started.

What the engineer checks

A structural engineer will typically review the existing house layout, roof framing, ceiling framing, floor framing, bracing layout, wall position, proposed opening and foundation support. The engineer may need photos, drawings, roof space information or a site inspection.

The design may include a beam, posts, connections, hold-downs, foundation details and bracing replacement. The aim is to make the new open-plan layout work structurally and practically.

Making the new space look right

A structural solution should work with the architecture. Sometimes the beam can be hidden in the ceiling. Sometimes it is more practical or more attractive to express the beam as a feature. The best option depends on ceiling depth, span, services, cost, construction access and the look the homeowner wants.

Early engineering input helps avoid awkward posts, bulky boxing, unexpected foundation work or last-minute changes during construction.

Frequently asked questions

Can I remove a non-load-bearing wall without an engineer?

Possibly, but it still needs to be confirmed that the wall is not load-bearing and does not provide bracing, fire separation or other required performance. A quick professional check can prevent expensive mistakes.

What replaces a load-bearing wall?

Usually a beam, supported by posts or existing walls. The load must then continue down to suitable foundations or supporting structure below.

Can an engineer help after council has issued an RFI?

Yes. SES Engineers can review the RFI, prepare calculations or details where required, and help respond to council queries.

How SES Engineers can help

SES Engineers provides wall removal and open-plan renovation engineering design for residential projects across New Zealand. We can prepare engineering design, calculations, consent documentation, PS1s, construction monitoring, site inspections, remote inspections, PS4s and council RFI responses where required.

Contact SES Engineers for pricing at www.sesengineers.co.nz. Pricing depends on the project scope, complexity, consent requirements, level of documentation required and whether inspections or PS4 documentation are needed.

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