PAS 2038 – Complete UK Guide

Differences Between PAS 2035 and PAS 2038

While they share a common philosophy, PAS 2035 and PAS 2038 differ in scope and application:

Importantly, PAS 2038 includes more emphasis on building services (like HVAC) and often deals with higher energy intensities.

Creating a Retrofit Strategy for Non-Domestic Buildings

A Retrofit Strategy serves as the central masterplan for any PAS 2038 retrofit project. It is developed and overseen by the Retrofit Lead, who is responsible for coordinating every aspect of the process from planning through to performance evaluation.

This strategy document ensures a clear, consistent vision for the project and helps align all stakeholders—from designers and engineers to contractors and auditors. It typically includes the following key components:

• Objectives and Performance Targets
  This section defines the primary goals of the retrofit—whether it’s reducing carbon emissions, improving Energy Performance Certificate (EPC) ratings, enhancing occupant comfort, or achieving operational cost savings. Targets should be quantifiable and tailored to the building’s usage, lifecycle, and stakeholder expectations.

• Risk Management Protocols
  Risks such as disruption to operations, budget overruns, or unforeseen structural issues can significantly affect retrofit outcomes. The strategy must outline a risk register, identify mitigation measures, and assign responsibility for monitoring and managing risks throughout the project lifecycle.

• Procurement and Delivery Models
  This part of the strategy defines how the work will be procured and executed. It could involve traditional tendering, design-and-build contracts, or performance-based agreements. It should also cover contractor selection criteria, timetable expectations, and supply chain considerations, especially for energy-efficient materials and systems.

• Verification and Performance Monitoring
  To ensure that the retrofit delivers its intended results, the strategy must include plans for ongoing monitoring, commissioning, and post-occupancy evaluation (POE). This includes using measured data to confirm energy savings, comfort improvements, and system performance against baseline conditions.

By creating a comprehensive Retrofit Strategy, organisations can avoid miscommunication, streamline project delivery, and ensure that all interventions contribute to long-term building performance improvements.

Building Fabric Improvements under PAS 2038

Improving the building fabric—the external envelope and structural components—is one of the most cost-effective ways to reduce energy demand. PAS 2038 emphasises a “fabric first” approach, meaning that insulation, airtightness, and glazing are addressed before mechanical interventions.

Considerations include:

• Wall, roof, and floor insulation upgrades

• High-performance windows and doors

• Thermal bridging identification and mitigation

• Moisture and condensation control

Improving the fabric reduces heating and cooling loads, which in turn reduces the size—and cost—of systems like HVAC.

Managing Services and Utilities in PAS 2038

Once the building fabric is optimised, attention turns to services—lighting, ventilation, heating, cooling, and controls. PAS 2038 insists on a thorough evaluation of these systems to ensure they are appropriately sized, efficient, and correctly controlled.

Effective upgrades may include:

• LED lighting with daylight and occupancy sensors

• Heat pump integration

• Smart building management systems (BMS)

• Zoned heating and cooling strategies

• Low-flow water systems

These elements contribute significantly to operational carbon reduction and occupant wellbeing.

Monitoring and Verification Requirements

PAS 2038 includes a strong emphasis on Post-Occupancy Evaluation (POE). This ensures that predicted energy savings and comfort levels are achieved in practice. It also helps to close the performance gap often seen in retrofit projects.

Verification methods include:

• Metered energy usage comparison

• Indoor air quality sensors

• Occupant surveys and interviews

• Thermal imaging and infiltration tests

The results feed into lessons learned and help refine future retrofit strategies.

The Retrofit Coordinator’s Role in PAS 2038 Projects

Although not always titled “Retrofit Coordinator” (as in PAS 2035), the equivalent role in PAS 2038 is known as the Retrofit Lead. This person is responsible for:

• Overseeing the assessment and strategy process

• Ensuring team competence and quality assurance

• Acting as a bridge between stakeholders

• Managing risks and compliance

Having a qualified Retrofit Lead ensures project accountability and integrity from start to finish.

Key Stakeholders and Their Responsibilities

A successful PAS 2038 retrofit relies on the seamless coordination of multiple stakeholders, each with specific responsibilities that align with different phases of the project. From setting the vision to ensuring technical compliance and verifying final outcomes, every role plays a part in delivering a compliant, high-performing retrofit.

Clear communication and defined responsibilities help prevent delays, reduce costs, and ensure long-term energy performance. The following are the core roles involved in a PAS 2038 project, each of which should ideally be filled by qualified professionals accredited by bodies such as CIBSE, REFCOM, or The Retrofit Academy:

• Building Owner/Client: Sets the strategic objectives, approves budgets, and ultimately funds the retrofit project.

• Retrofit Lead: Oversees the entire process, ensuring compliance with PAS 2038 and acting as the main point of coordination.

• Energy Assessor: Conducts energy audits, identifies performance gaps, and recommends improvement measures based on data.

• Design Professionals: Translate performance objectives into practical, buildable solutions covering both fabric and systems.

• Contractors: Carry out the physical retrofit works, ensuring quality and safety on site.

• Commissioning Agent: Tests and verifies that installed systems function as intended and meet performance targets.

Each party must be competent and ideally certified under relevant accreditation schemes like CIBSE, REFCOM, or the Retrofit Academy.

Training and Qualifications for PAS 2038 Practitioners

As PAS 2038 becomes widely adopted, the demand for qualified practitioners is rising. Recommended qualifications include:

• Level 5 Diploma in Retrofit Coordination

• Non-domestic Energy Assessor Certification (NDEA)

• CIBSE Low Carbon Consultant

• BREEAM Assessor Accreditation

In addition, CPD in energy modelling, air quality management, and building physics is highly recommended.

Documentation Required for PAS 2038 Compliance

Thorough documentation is essential to demonstrate compliance. Core documents include:

• Retrofit Strategy Document (RSD)

• Energy Audit Report

• Risk Register

• Specification and Design Drawings

• Installation Records

• Performance Verification Report

This paperwork serves as proof of due diligence and can be critical for funding, insurance, and regulatory reviews.

Certification Bodies and Accreditation Pathways

Although PAS 2038 is not a legal requirement, many organisations are using certified verification to add credibility. Recognised bodies include:

• Simply Certification

• Elmhurst Energy

• Stroma Certification

• BRE Global

Engaging with accredited professionals ensures that the retrofit process aligns with industry-recognised best practices.

How to Pass a PAS 2038 Compliance Check

Achieving compliance with PAS 2038 involves more than just technical upgrades—it requires a clear process, professional collaboration, and thorough documentation from start to finish.

Here are key steps to help ensure a successful audit:

• Start with a robust project brief and clear objectives
  Define what you want the retrofit to achieve—whether it’s energy savings, improved comfort, or regulatory compliance. A well-articulated brief keeps the project focused and measurable.

• Engage qualified professionals early
  Appoint a competent Retrofit Lead, along with accredited energy assessors, designers, and contractors. Early involvement ensures their expertise shapes the project from the outset.

• Document every stage of the process
  Keep a detailed record of assessments, decisions, installations, and verifications. This evidence forms the backbone of your compliance and will be reviewed during the audit.

• Undertake quality assurance checks at each milestone
  Don’t wait until the end. Use interim checks to confirm that works meet the specifications and performance expectations at each stage of the retrofit.

• Monitor performance post-retrofit
  Once works are complete, carry out post-occupancy evaluation (POE) and performance monitoring. This ensures that predicted energy savings and comfort improvements are realised in practice.

Using our PAS 2038 compliance checklist throughout the project can help you stay on track, flag potential issues early, and maintain full visibility over each phase of delivery.

The Economic Benefits of PAS 2038 Compliance