A new framework and a transitional choice
The Swedish National Board of Housing, Building and Planning, Boverket, adopted BFS 2026:9 on 25 August 2026. The regulations entered into force on 1 October 2026 and contain requirements relating to energy management and thermal insulation in buildings. They form part of Sweden’s implementation of the recast EU Energy Performance of Buildings Directive, Directive (EU) 2024/1275.
BFS 2026:9 regulates matters including the calculation of energy performance, thermal transmittance and specific electrical power use. It also requires buildings to be designed with reasonable consideration of the potential to use solar energy technology.
For projects already under development, the transitional provisions are particularly important. The former Boverket Building Regulations may generally be applied where an application for a building permit or a notification is submitted before 1 October 2027. Where neither is required, the work must begin before that date. If the former rules are used, the relevant former provisions must be applied consistently. An exception applies to certain requirements for building automation and control systems.
The applicable regulatory framework should therefore be identified early in the project rather than being treated solely as a question of final compliance.
Energy compliance enters project documentation
BFS 2026:9 requires professional design to ensure that the applicable requirements can be met. Unless unnecessary, the design must be documented and identify matters including the building’s intended use, relevant design conditions, assumptions, inputs and outputs. Compliance must be checked during design and construction, in the completed building, or through a combination of these methods. The results of the checks must also be documented.
These requirements have a contractual dimension. Project documentation should identify the applicable regulatory framework and clearly allocate responsibility for energy calculations, design assumptions, building systems, documentation and verification. Otherwise, gaps may arise between regulatory requirements and the parties’ contractual responsibilities.
For alterations to existing buildings, the rules require consideration of whether existing deficiencies can be remedied as part of the planned works and whether the alteration could adversely affect energy performance or thermal insulation. The requirements may be adapted in specified circumstances, including for technical reasons, excessive cost in relation to the expected benefit or the need to preserve cultural heritage values.
Property transactions and due diligence
Amendments to Sweden’s energy performance certificate rules under BFS 2026:10 also applied from 1 October 2026, without general transitional provisions. The changes concern the content of certificates and how energy performance is expressed and presented.
For property transactions, the practical analysis should therefore extend beyond confirming that a required energy performance certificate exists. Depending on the property and any contemplated works, buyers should consider which regulatory framework applies, the information supporting the stated energy performance, potential investment requirements and whether available project documentation demonstrates compliance.
What businesses should focus on now
The new framework brings energy compliance further into project planning, contractual documentation and property due diligence. Businesses involved in Swedish construction projects or property transactions should identify the applicable rules early, align technical and contractual documentation with that choice and assess energy performance and potential upgrade requirements when planning renovations or acquisitions.