How to Reduce Costly Variations During a Commercial Build

Changes during construction aren't always avoidable. But understanding what causes them can help you reduce unnecessary costs, delays and disruption to your project.

When planning a new commercial or industrial building, establishing a realistic budget is only one part of the
equation. Keeping that project aligned with its original scope is equally important. Construction variations are a common part of building projects, particularly where operational requirements, site conditions or design decisions change throughout the process.

While some variations are necessary, others can be reduced through better preparation, clear communication
and early decision-making. Here’s what businesses and developers should consider before construction begins:

What is a construction variation?

A construction variation is a change to the agreed scope of work under a construction contract. Variations may involve changes to materials, structural design, building dimensions, services, specifications or construction methods.Depending on the contract, these changes can affect the final project cost, construction programme or both.

For example, introducing an additional roller door after structural design has been completed may requires changes to framing, cladding, engineering documentation and associated construction work. What initially appears to be a relatively minor adjustment can have implications across several parts of the project.

1. Establish a clear project scope from the beginning

One of the most effective ways to reduce avoidable variations is to establish a detailed project brief before design and pricing are finalised. A clear scope helps ensure everyone involved understands what the building needs to achieve.

For commercial and industrial facilities, this should consider:

– The building’s intended purpose and operational requirements.
– Overall dimensions and required clear heights.
– Vehicle access, loading areas and door locations.
– Machinery, storage and equipment requirements.
– Office, amenities and internal fit-out requirements.
– Electrical, plumbing, ventilation and other building services.
– Potential future expansion.

The more accurately these requirements are identified early, the less likely the project is to require significant
changes later. A practical starting point: Involve the people who will actually use the building when developing your brief. Warehouse managers, equipment operators and operational teams may identify requirements that aren’t immediately obvious during initial planning.

2. Investigate site conditions early

Unexpected ground conditions can introduce additional costs and programme changes during construction. Factors such as unsuitable soils, groundwater, buried services and existing site constraints can affect foundations, earthworks and the construction methodology. Where appropriate, early site investigations can help identify these risks before the project reaches construction. This may include geotechnical assessments, topographical surveys, drainage investigations and locating existing underground services.
Although investigations have an upfront cost, they can provide valuable information for design, budgeting and risk management. Importantly, no investigation can eliminate every unforeseen ground condition. The objective is to reduce uncertainty and make informed decisions about the risks that remain.

3. Finalise key design decisions before construction

Commercial building projects involve a series of interconnected design decisions. Changes to one element can influence several others. For example, increasing the height of an industrial building may affect structural requirements, cladding quantities, access systems and potentially the consenting process. Similarly, relocating a large door opening may require adjustments to the structural framing and internal layout.

Before construction begins, confirm important design details such as:

– Building height and clear-span requirements.
– Door sizes and locations.
– Internal column positions.
– Structural loading requirements.
– Cladding and roofing specifications.
– Future expansion provisions.
– Major building services and equipment interfaces.

Finalising these decisions early can reduce the likelihood of redesign, rework and additional procurement
costs.

4. Compare construction quotes on a like-for-like basis

Not every commercial building quote includes the same scope of work. A lower initial price may exclude elements that another proposal has already accounted for. When comparing quotes, look beyond the total figure and review what’s included, excluded or allowed for provisionally. Areas worth checking include:

– Site preparation and earthworks.
– Foundations and concrete work.
– Structural steel supply and installation.
– Roofing, cladding and insulation.
– Doors, windows and other openings.
– Building services.
– Engineering and consent-related services.
– Access equipment and construction logistics.

A useful question to ask: What work is not included in this price that will still be required to complete the project? Understanding exclusions early can help prevent additional costs from being mistaken for unexpected variations later.

5. Establish a clear variation approval process

Even with detailed planning, some changes may still be necessary. The important thing is having a clear process for assessing and approving them. Before authorising a variation, the project team should establish:

What is changing? Clearly describe the proposed adjustment and why it’s required.
What will it cost? Request a documented breakdown of the additional or reduced costs.
Will it affect the programme? Determine whether the change will influence procurement, construction sequencing or the completion date.
Who needs to approve it? Confirm the person authorised to approve the variation under the construction contract.
Has the change been documented? Ensure the agreed scope, cost and programme implications are recorded before proceeding, in accordance with the contract. This creates a clearer record of decisions and helps reduce misunderstandings between the parties involved.

6. Consider future operational requirements

A building designed solely around current operations may require changes sooner than expected. For growing businesses, it can be useful to consider how the facility might need to perform over the next five to ten years. Will additional machinery be introduced? Could storage requirements increase? Might vehicle sizes or operational workflows change? Not every future requirement needs to be incorporated immediately. However, considering potential growth during initial design can help identify opportunities to make the building more adaptable.For example, allowing for future access requirements or considering potential building expansion during structural planning may be more practical than revisiting those decisions after construction. The objective isn’t to build more than you need. It’s to make informed decisions about the flexibility your business may require.

A commercial construction variation checklist.

Before construction begins, consider whether you can confidently answer the following questions:

– Is the project scope clearly documented?
– Have the building’s operational requirements been confirmed?
– Have appropriate site investigations been completed?
– Are the major structural and architectural decisions finalised?
– Have all relevant consultants reviewed their design interfaces?
– Are quote inclusions, exclusions and provisional allowances understood?
– Is there a documented process for approving variations?
– Have potential programme and budget risks been considered?
– Is there a realistic contingency allowance for unforeseen work?

If several of these questions remain unanswered, it may be worth resolving them before progressing further.