Insights | 4 cost controls in Australia’s transmission projects

Change your location to view content tailored for you.

9 November 2026 | 5 min | Article

Major energy transmission projects are showing some of the same early cost warning signs seen during Australia’s transport megaproject boom. This time, there is still an opportunity to intervene.

As renewable generation connections accelerate, rising capital costs and tighter investor scrutiny mean delivery confidence now hinges on whether constructability, schedule certainty, social licence and cost forecasts stand up to scrutiny. Delays, rework and fragmented delivery no longer stay contained at the project-level but compound across portfolios, pushing out timelines and increasing whole-of-system costs.

This report shares why cost control in energy transmission is won early and four proven ways to improve cost control in Australia’s transmission build out.

Download report

On this page

Key insights

Case study: Australia’s first REZ

What does this mean?

Four proven ways to improve cost control in Australia’s transmission build out

Experience across transmission, generation, storage and grid integration – benchmarked against global best practice – points to a consistent lesson: effective cost control starts early and continues throughout delivery.

The energy industry now needs to make these lessons transferable by moving knowledge between projects to foster a consistent, shared approach to cost control that can bend the cost curve at pace.

Figure 1. Four proven ways to improve cost control in Australia’s energy transmission infrastructure build out.

1. Design for energisation success

The biggest cost and schedule outcomes are determined at the outset. Rushing front-end decisions to meet design milestones creates risk of delays and cost escalations once projects move into construction and commissioning. Global research into major infrastructure delivery by Flyvbjerg and Gardner (2023)¹ argues for a ‘plan slow and act fast’ approach. This means investing time upfront to resolve details that will reduce construction time as well as rework and commissioning risk. Once procurement starts and costly on-site teams mobilise, this front-end decision-making helps deliver efficiently, to budget and to schedule.

2. Make projects approval-ready 

In Australia, design approval gates, approvals pathways, workforce capacity and climate resilience regularly become key drivers of schedule and cost. With approvals, landholder engagement and design often progressing in parallel, teams also need to design for Australian regulatory and design gate expectations, so decisions are approval-ready and traceable from the outset. This reduces churn and avoids ‘stop-start’ delivery – it also protects investor confidence.

3. Reduce offset costs and de-risk approvals

Biodiversity offsets can materially shape route selection, CapEx, and investor confidence and approval timelines. Teams can avoid redesign, reduce contestability and improve certainty for investors, regulators and communities when offset implications are understood early. Treating offsets as a strategic design input, with visibility of ground and land values and escalation factors (labour, commodities and land), supports approvals and investment decisions. Analytics and geospatial modelling can significantly reduce offset requirements while at the same time streamlining approvals and reducing project risk.

4. Apply learnings nationally

Transmission delivery is as much a commercial and behavioural challenge as it is a technical one. Incentives that are aligned around shared outcomes encourage teams to surface issues sooner as well as solve problems faster and protect schedule certainty. That makes it more likely cost forecasts will hold and lessons learned can be transferred from one project to the next. A national approach is one way to make collaboration real through transparency and incentives that reward collaboration, reduce duplication, manage sequencing impacts and sustain industry capability.

In this video, Aurecon's Renene Windsor shares four ways to improve cost and schedule outcomes for major energy transmission projects.

Case study: Australia’s first REZ

CASE STUDY

Flexible design improves delivery for Australia’s first REZ

For the development of Australia’s first Renewable Energy Zone with new market participants, it required early design priorities to be right, given the influence on later delivery phases.

As a set of design standards hadn’t yet been established, initial design work progressed in parallel with procurement, approvals and investor decision gates. Conservative technical assumptions were adopted to provide certainty and satisfy assurance expectations but did not always reflect eventual construction methods, access constraints or grid connection staging.

As delivery teams mobilised and local conditions become better understood, elements of the design were reassessed and optimised to improve constructability and cost efficiency, highlighting the value in preserving optionality right through delivery.

What this means for cost control on energy megaprojects?

Australia’s energy transition is one the most significant challenges of our time. To meet this challenge we see optimism as a strategic choice. It’s a belief that progress is possible, even in the face of adversity and change.

One of the most important things Australia can do in the face of rising costs in energy transmission projects is to make sure that lessons across design, construction, environmental mitigation and commerciality are shared more freely between projects.

Applying these lessons between projects and partners will help the industry bend the cost curve at pace, reduce whole-of-system cost pressures and deliver the infrastructure Australia needs for the energy transition.