LCA A4 and A5: The Complete Guide for Construction Managers

From 1 July 2025, all new buildings and extensions in Denmark must document the climate impact from the construction process, specifically Module A4 (transport) and Module A5 (construction site operations). A new combined limit of 1.5 kg CO₂e/m²/year applies, making A4 and A5 reporting a core compliance task for both contractors and developers.

This guide gives you a clear, efficient overview of both modules: what they include, what data to collect, and how to stay compliant without drowning in paperwork.

If you need the deeper, full-length guides:
→ Full A4 guide (long version)
→ Full A5 guide (long version)

1. What Are Modules A4 and A5?

In the building’s life cycle assessment (LCA), A4 and A5 form the final stages of the “construction phase” under EN 15978.

Module A4 — Transport to the construction site

Includes:

• Transport of building products from the manufacturing unit (factory) to the construction site
  
  • Including: Vehicle type, full transport distance, load factor, fuel type
• Transport of equipment (cranes, scaffolding, etc.) to and from site
  
  • Including: Vehicle type, distance, load factor, fuel type

Does not include:

• Worker transport
• Office commuting
• Off-site processes covered under A1–A3
  
  

Module A5 — Construction and installation process on site

Includes:

• Site energy use (electricity, diesel for machinery, HVO, generators)
• Temporary heating/drying
• Waste generation and waste transport
• Material loss and spillage

Does not include:

• Building operation (B6)
• End-of-life stages (C1–C4)
• Consumption from small machines (< 1 t)

2. Why A4 and A5 Matter Now

New 1.5 kg CO₂e/m²/year limit

A4 and A5 combined have their own emission cap. Exceeding it or not producing the correct documentation can trigger:

• additional municipal review
• extra documentation
• delays
• fines and legalisation requirements

Early data collection is now essential

If A4 and A5 data is collected only at the end of the project, it’s hard to:

• track missing data deliveries
• ensure not to exceed the limit
• apply measures to lower CO2 consumption
• comply with the limit

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3. What to Collect: A4 vs A5 Overview

A4: Transport Data (Short Checklist)

Delivery notes, with the following data:

• Supplier name
• Product/building material or EPD identifier
• Dispatch address of the manufacturing unit (factory)
• Site address
• Distance (km) or postal codes so the distance can be calculated
• Vehicle type 
• Fuel/energy type
• Load factor
• Quantity 
• Delivery date
• Evidence 

OBS: Delivery notes can only be used for A4 if they document transport directly from the manufacturing unit to the construction site. Delivery notes from wholesalers or terminals typically only cover the final leg of transport and therefore cannot be used alone for A4. If the full transport distance from the production facility is unknown, standard transport values must be applied.

EPDs

Collect EPDs for all materials and check whether the A4 value is included. EPD A4 values can only be used if the actual transport distance from the manufacturing unit to the construction site is known. For materials delivered via wholesalers or terminals where full transport distance is unknown, EPD A4 values cannot be applied, and standard values must be used instead, even if the EPD contains an A4 scenario.

Standard values:

Use Table 10 when neither an EPD with known full transport distance nor a valid delivery note covering the entire transport from the manufacturing unit is available.
https://www.bygningsreglementet.dk/bilag/b2/bilag_2/

Pro tip: A4 becomes difficult when suppliers don’t include the required fields. Make sure A4 requirements are included in all contracts and purchase orders.

A5: On-Site Data (Short Checklist)

Site Energy (electricity + fuels)

• kWh of electricity
• Liters/kg of diesel, HVO, petrol
• Equipment/machinery list (optional < 1 t)
• Heating of temporary buildings

Waste

• Total waste generated
• Breakdown by category
• Recycling vs incineration vs landfill
• Waste transport distances and vehicle types

Pro tip: Always avoid mixed fractions, as they tend to be categorised as plastic, resulting in a few high CO2 calculation.

Site Duration and Logistics

• Construction start/end date
• Temporary installations
• Material loss/spillage
• Emission factors used

4. Common Pitfalls

• Late data collection → missing deliveries and untrackable site energy
• No dispatch address → cannot calculate A4 distances
• Using wholesaler delivery notes as A4 evidence → do not represent full A4 transport
• “Truck” instead of vehicle class → insufficient for advisors
• Mixed waste → High CO2 values
• Overusing generic values → can inflate emissions by 30–70%
• Mixing A4 and A5 → must be documented separately even though the limit is shared

5. Who Is Responsible for A4 and A5?

6. How to Actively Reduce A4 and A5 Emissions

Reducing A4 (transport)

• Choose nearby suppliers
• Consolidate deliveries
• Use electric/HVO trucks

Reducing A5 (on-site process)

• Switch to machinery with lower few consumption
• Plan temporary heating/drying carefully
• Improve waste sorting
• Optimise site layout and logistics

Small operational improvements = big CO₂ reductions.

7. Making A4 and A5 Reporting Easier 

LCA A4 and A5 reporting often becomes a manual mess: invoices, delivery notes, fuel slips, waste reports, gate logs, emails from suppliers, missing data, and inconsistent formats.

A reporting platform solves this by handling the structure for you.

With Acembee, you can:

1. Use the data that already exists in your project
Forward invoices, delivery notes, and waste slips to a project email. The system extracts A4 and A5 fields automatically and organises them by supplier and date.

2. Track A5 energy automatically
Electricity meters connect directly, and fuel data can be taken from machinery logs or telematics — no spreadsheets or manual summaries.

3. See the full picture from day one
The dashboard shows which suppliers have delivered data, what is missing, and how emissions develop as the project progresses.

4. Export complete documentation
Generate advisor-ready A4/A5 documentation with evidence files, transport calculations, waste amounts, and the required CSV download.

5. Keep the implementation simple
Acembee runs in the background and fits how construction teams already work. No new apps on site, no extra admin — just clear structure and lower risk.

If you want to see the workflow in practice, you can book a short demo.

Summary: What Construction Teams Should Do Now

1. Collect A4 and A5 data from day one.
2. Add A4 requirements to all contracts.
3. Keep all evidence centralised.
4. Use conservative assumptions when data is missing. 
5. Use a reporting platform to reduce workload.