Transitional rules 2025: When do the new A4-A5 requirements apply?

The decisive moment for whether the new A4-A5 requirements apply to your project is the date of the building permit application — not the date the permit is granted, and not the date construction begins.

Application submitted	Rules
Before July 1, 2025	Old rules apply — even if construction is not completed until 2027 or later.
July 1, 2025 or later	New rules apply — incl. A4-A5 limit of 1.5 kg CO₂e/m²/year.

This distinction is important. If you submitted your building permit application on June 30, 2025, you are under the old rules. If you submitted on July 1, 2025, you are under the new rules. This applies regardless of when the building permit is actually issued.

The new rules involve three major changes compared to what applied before July 1, 2025:

1. The 1,000 m² area requirement is scrapped

Under the old rules, climate requirements only applied to buildings over 1,000 m². This meant the vast majority of construction projects were not covered. Under the new rules, A4-A5 requirements apply to almost all new construction — the area requirement has been removed.

2. A4-A5 has its own separate limit

Previously, A4-A5 was part of the overall climate calculation. Now the construction process has its own, separate limit of 1.5 kg CO₂e/m²/year. You can no longer compensate for high construction process emissions with low material emissions.

3. Differentiated limits for materials

The old flat limit of 12.0 kg CO₂e/m²/year for materials has been replaced by differentiated limits (4.0-8.0 kg depending on building type). This is a significant tightening for certain building types.

The rules apply more broadly than many expect. Here is the full overview:

New construction

Building type	Covered?
Heated buildings over 50 m²	Yes — regardless of type.
Unheated buildings over 50 m² (parking structures, warehouses)	Yes — this is new. Was not covered before.
Unheated buildings under 50 m²	No — exempt.

Extensions

Building type	Requirement
Apartments, offices, institutions	A4-A5 required regardless of extension size.
Single-family homes, row houses, holiday homes	Only for extensions over 250 m².

Exemptions

• Renovation and rebuilding: NOT covered. The rules apply only to new construction and extensions.
• No geographic differences: The rules are national and apply uniformly across all municipalities.

Extensions are one of the areas where the new rules create the most confusion. Here are the key points:

• Apartments, offices, and institutions: Extensions are covered regardless of size. Even a 30 m² extension to an office complex triggers A4-A5 documentation requirements.
• Single-family homes, row houses, and holiday homes: The extension must exceed 250 m² before the requirements apply. In practice, this therefore rarely affects private single-family homes.

Renovation and rebuilding of existing buildings is not covered by the new A4-A5 rules. The rules only apply where something new is constructed — either an entirely new building or an extension.

There are no geographic differences. The rules apply uniformly across the country, regardless of which municipality you build in.

The transitional rules are clear, and there is no ambiguity about the cutoff date. Here are the actions that make sense depending on your situation:

• Did you apply before July 1, 2025? You are under the old rules. But consider documenting A4-A5 continuously anyway — it gives you a head start for future projects, and the experience is valuable.
• Did you apply after July 1, 2025? The new rules apply. Begin data collection from day one. Clarify responsibility distribution in contracts. Set up a calculation tool early.
• Are you planning to apply soon? Be aware that all new construction over 50 m² is now covered — including unheated buildings such as parking structures and warehouses. They were not covered before.

The limit of 1.5 kg CO₂e/m²/year tightens to 1.3 in 2027 and 1.1 in 2029. The sooner you build experience with A4-A5 documentation, the better prepared you are for the coming tightening. Read our complete BR18 A4-A5 guide to get started.