PACER and the next step in planning-led carbon accountability

Earlier in July, I had the opportunity to speak at the launch event for the Planning Application Compliance Evaluation Readiness (PACER) tool at Westminster City Hall. The discussion focused on a question that is becoming increasingly important for the built environment: how do we move from producing Whole Life Carbon Assessments (WLCAs) to enabling clearer, more consistent and more accountable carbon-informed decisions through planning?

As carbon requirements become more embedded in planning policy, the industry is reaching an important inflection point. The challenge is no longer whether projects can calculate whole life carbon, it is whether those calculations can be understood, challenged and used to inform better decisions. A carbon assessment only creates value if it helps people take appropriate action. This is where PACER feels particularly relevant.

From carbon assessment to planning evidence

Cundall’s experience with PACER to date has been through a live planning context, specifically a Westminster project that required a WLCA, and as part of the planning process, had to be submitted through the PACER platform. Being one of the first teams to go through the process gave us a valuable opportunity to test the platform in practice. This distinction matters.

In planning, whole life carbon is not just a technical calculation; it is a critical source of evidence. The local planning authority reviewing an assessment needs to be confident that the methodology used is robust, the assumptions are logical and transparent, and the design team has actively explored carbon reduction opportunities. PACER provided a structure for turning a detailed technical assessment into a more reviewable, traceable and decision-ready format.

A detailed platform, not an additional assessment

At first glance, the volume of information requested can feel significant, but the more we worked through the submission, the clearer it became that PACER was not asking for a separate assessment; rather, it was asking for clarity around the assessment we had already produced. From an applicant’s perspective, PACER was comprehensive, rather than complex.

Regarding the Westminster project, the assessment had already been developed in line with recognised whole life carbon methodologies, including RICS Whole Life Carbon Assessment v2, BS EN 15978, CIBSE TM54 and TM65 principles. PACER aligned closely with that established evidence base. We were not rebuilding calculations or creating new results; we were testing how well our assumptions, quantities, and reduction measures could stand up to PACER’s structured review.

Why transparency matters

Whole life carbon information is often fragmented across assessment reports, energy modelling outputs, structural studies, cost plans, circular economy statements and material schedules. Individually, each document may be robust, but collectively it can be difficult to follow the evidence trail from design assumption to carbon outcome. Transparency, therefore, is one of the strongest benefits of PACER.

By bringing key information into one structured environment within a standardised format, PACER makes that evidence trail more visible. Reviewers can move from project overview through to material quantities, carbon factors and optimisation measures.  Again, this matters because confidence in a carbon assessment does not come from the final number alone; it comes from understanding how that number has been reached.

The decisions behind the numbers

PACER also captures the carbon reduction journey. On the Westminster project, measures were identified across structure, building fabric, finishes and services, helping demonstrate how carbon reduction had been considered through design and specification decisions rather than treated as a retrospective reporting exercise.

This is where the platform becomes particularly useful. Carbon reduction is rarely the result of one decision. It is usually the cumulative effect of many choices made by different disciplines at different points in the design process. PACER helps make those choices visible, which is essential if we want WLCAs to influence low-carbon outcomes rather than simply record them.

Insights from the launch event

The launch event on 8 July, hosted by Westminster City Council in collaboration with Preoptima, highlighted a broader direction of travel for the industry. Planning authorities are being asked to engage with increasingly complex carbon information, while applicants need clearer expectations on what good evidence looks like. The opportunity for digital tools such as PACER is not simply to make submissions more efficient but to make the entire review process more consistent, transparent and useful.

Importantly, this does not remove the need for professional judgement. WLCAs still require an understanding of the project context, robust assumptions and the careful interpretation of data-informed insights. PACER can provide a stronger basis for case officer judgement by making information easier to interrogate, compare and challenge.

Lessons from a first-time submission

As with any new platform, there is a learning curve. First-time users need to understand how the system is structured and how the submission should be populated. However, once that structure is understood, the process becomes logical.

In our experience, the effort required was justified by the improved consistency, transparency and reviewability of the submission. As carbon assessments move beyond planning compliance, this is particularly relevant. A structured digital record can support continuity between planning, pre-commencement and post-completion stages, helping ensure that carbon commitments remain connected to the design, procurement and delivery decisions that follow. This flow of information can also help mitigate the performance gap by reducing the discrepancies that often emerge between as-designed assumptions and as-built outcomes.

From reporting to accountability

What stood out most was how effectively PACER aligned with our existing methodologies, requiring minimal reworking of calculations, while clearly presenting the assumptions, material choices and carbon reduction measures behind the results. On the Westminster project, PACER helped convert a technically detailed WLCA into a clear, review-ready submission.

Ultimately, the key lesson is that the future of whole life carbon is not just about better calculations, it’s about better evidence, clearer accountability and stronger links between assessment and action. As requirements mature, the industry needs tools that make carbon information more accessible and useful for decision makers, design teams, clients, planning authorities, and fundamentally, for supporting carbon reduction in practice.

PACER is a positive step in that direction, helping move the conversation from carbon reporting towards carbon accountability.