What is A4-A5 in BR18?

A4 covers transport of building materials and equipment to the construction site. A5 covers energy consumption, waste handling, and soil transport at the construction site. Both now require LCA documentation under BR18 §297-298 for buildings over 50 m².

What is the A4-A5 emission limit?

The current limit is 1.5 kg CO₂e/m²/year for standard construction. It tightens to 1.3 in 2027 and 1.1 in 2029. For the low-emission class, the limit is already 1.1 kg CO₂e/m²/year.

How does A45 climate calculation work?

Upload your invoices and delivery notes. Our AI automatically extracts relevant data (materials, weight, distances, fuel) and calculates CO₂ emissions per BR18 Table 8, 10, and 11. You review and approve, and the platform generates BR18-compliant reports.

BR18 — LCA A4 & A5

Automated A4-A5 climate calculations per BR18 — from invoice to report

Upload your invoices. Our AI extracts the data, calculates emissions per BR18, and generates compliance reports — ready for authorities. Save 12+ hours per project.

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New Office Building East

4,200 m² · BR18 A4-A5

Compliant

A4 Transport

0,42

kg CO₂e/m²/yr

A5 Site Energy

0,31

kg CO₂e/m²/yr

Total A4+A5

0,73

of 1.50 limit

Invoices scanned

this month

CO₂ budget usage

49%

0.73 kg CO₂e/m²/yr used

Limit: 1.50

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The challenge

Construction is one of the largest contributors to climate change.

The Danish government has responded with updated BR18 regulations, requiring life cycle assessment documentation for execution phases A4 (transport of materials) and A5 (consumption and waste on the construction site). For most players in the building industry, this means new complexity, new processes, and many parties involved.

~37%

of global CO₂ emissions come from the building sector

A4+A5

A4 is transport of materials. A5 is consumption and waste on the construction site. Both now require LCA documentation under BR18.

2025

Buildings over 50 m² with building permits applied for after July 2025 are subject to the new requirements.

Many parties, many methods

A construction project involves many different companies and suppliers. There are multiple calculation methods, and it's unclear which data each party should deliver. A45 creates a common foundation.

Error-prone calculations

Spreadsheet-based LCA calculations are prone to mistakes, leading to inaccurate emission reports and compliance risks.

Regulatory uncertainty

The new requirements are complex. Many players in the building industry lack the expertise or tools to correctly document A4 and A5 phases.

Our approach

From invoice to emission report in minutes, not weeks.

A45 replaces manual spreadsheets with an intelligent platform purpose-built for BR18 A4 and A5 documentation. Upload your invoices, and let our AI do the rest.

AI-powered document analysis

Covers all of A4-A5: transport, site energy, and waste. Upload your documents – our AI navigates the BR18 regulations so you can focus on building.

BR18-compliant calculations

Automatic CO₂ calculations per BR18 Table 8, 10, and 11 with full traceability to the legislation.

Compliance & projections

Track your CO₂ usage continuously against the BR18 limit, and see projected emissions early so you can adjust before exceeding the threshold.

Method comparison

Compare calculation methods (measured, EPD, standard values) to find the most advantageous one.

Team collaboration

Invite consultants, subcontractors, and developers. Everyone contributes to the same documentation.

Professional reports

Generate PDF reports ready for regulatory submission with full documentation of all calculations.

Platform overview

One platform for complete A4 & A5 compliance.

From data collection to final report — manage every step of your A4 & A5 documentation for the execution phase in one place.

AI Scanner

How the scanner works.

From raw invoice to verified emission data. No manual data entry. No spreadsheets.

Upload invoice

Upload your supplier invoices, delivery notes, or transport documents. The AI automatically extracts the relevant data.

Choose method

The AI recommends a calculation method and automatically determines whether it's an A4 or A5 emission. You choose the final method.

Confirm draft

A draft is created that you can review, adjust, and experiment with different calculation methods.

Report generated

Approve the emission, get an overview of the project's expected emission, and generate a BR18-compliant report.

INVOICE

Nordisk Byggemateriale A/S

DATE

2025-01-14

Concrete C30/3742 m³

Transport — Roskilde → CPH38 km

Diesel truck (Euro 6)2 trips

Crane service8 hours

Pump rental1 day

AI EXTRACTION COMPLETE

A4 Transport emissions1.84 kg CO₂e/m³

A5 Construction emissions3.21 kg CO₂e/m³

Total project impact212.1 kg CO₂e

Confidence: 98.2%

Our vision

Toward a sustainable building industry.

The climate transition in construction isn't just about better materials — it's about better information. When every transport, every installation, every piece of equipment is documented and measured, we create the foundation for genuinely sustainable building practices.

A45 exists to make this documentation layer invisible. Not another burden for project managers, but a seamless part of how buildings are delivered. We believe that when compliance becomes effortless, the industry can focus on what matters: building better.

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Founding Member benefits

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Free onboarding session

30-minute video walkthrough of your first project

Direct feature influence

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Priority support

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