Carbon audits: how to get started

If you're serious about sustainability, you need to know your starting point. A carbon audit is the most reliable way to measure your building's carbon footprint, identify hotspots, and develop a reduction strategy. Here's how to get started.

What is a carbon audit?

A carbon audit (or greenhouse gas assessment) quantifies the total carbon emissions associated with a building's operation. It typically covers Scope 1 (direct emissions from on-site fuel combustion), Scope 2 (indirect emissions from purchased electricity), and Scope 3 (other indirect emissions, such as business travel, waste, and water).

Step 1: Define the scope

Start by deciding which emissions you'll measure. For most building owners, Scope 1 (gas, oil) and Scope 2 (electricity) are the minimum. Scope 3 is optional but increasingly important for ESG reporting and net-zero commitments.

Also define the boundary: will you audit the whole building, a specific tenant space, or a portfolio of buildings? Be clear about what's included and excluded.

Step 2: Gather data

This is the most time-consuming part. You'll need:

• Energy bills — electricity, gas, oil, district heating (at least 12 months).
• Transport records — if including Scope 3, gather data on business travel and fleet vehicles.
• Water and waste records — also Scope 3, but important for a full picture.
• Refrigerant records — leaks from AC and refrigeration systems can be significant.

If you don't have perfect data, don't worry — estimates can be used initially, and you can improve accuracy over time.

Step 3: Calculate emissions

Use emission factors (available from UK Government conversion factors or the IPCC) to convert energy consumption into CO₂e (carbon dioxide equivalent). For example:

• 1 kWh of grid electricity = ~0.2 kg CO₂e (UK average, reducing as grid decarbonises).
• 1 kWh of natural gas = ~0.18 kg CO₂e.

Multiply your consumption by the relevant factor, and sum across all sources to get your total carbon footprint.

Step 4: Analyse and benchmark

Once you have the numbers, compare them to industry benchmarks (e.g., BREEAM, RICS, or Energy Performance Certificates). Look for anomalies — is your energy use higher than expected? Are there seasonal spikes you can explain?

This analysis will reveal the biggest opportunities for reduction. Common hotspots include:

• Inefficient HVAC systems.
• Poor insulation and air leakage.
• Outdated lighting and controls.
• Fleet vehicles or business travel.

Step 5: Develop a reduction plan

Based on your findings, create a prioritised list of actions. The most cost-effective measures are usually:

• Energy efficiency (LED lighting, HVAC upgrades, controls).
• Fabric improvements (insulation, windows, airtightness).
• Renewable energy (solar PV, heat pumps, on-site generation).
• Behavioural change (staff engagement, green travel plans).

Set a clear target — for example, 30% reduction by 2027, and net-zero by 2035. Then assign responsibility and track progress regularly.

Step 6: Measure, report, and iterate

A carbon audit is not a one-off exercise. To stay on track, you should:

• Monitor energy consumption monthly and report quarterly.
• Update your audit annually (or whenever major changes occur).
• Share progress with stakeholders — transparency builds trust.

Many organisations now include carbon reporting in their annual sustainability or ESG reports, which is increasingly expected by investors, regulators, and customers.

How ROKER67 can help

We offer end-to-end carbon audit services, from data collection and calculation to reduction strategy and ongoing monitoring. Our approach is practical, transparent, and aligned with the UK's net-zero targets. We work with you to understand your unique challenges and develop a plan that works for your business.

We've helped clients in commercial, public, and residential sectors reduce their carbon footprints by 20-50% within the first year. Contact us to discuss how we can support your net-zero journey.