Setting benchmark values for apartment blocks in Norway as the basis for GHG emission reduction along the building process

• A review of regional building regulations, GHG voluntary frameworks, and relevant studies has revealed inconsistencies. • System boundaries must be harmonised at a national and international level. • A three-tiered benchmark system (Target, Reference, Limit) for apartment blocks in Norway has been defined. • Climate change targets and policy goals require reduction strategies from the early design phase. • The impact of various reduction strategies is comprehensive in different functional units. Defining GHG emission benchmarks for new buildings and adapting national roadmaps to tighten the benchmark values over time are among the key measures for achieving climatic goals in the construction industry. A review of building technical regulations, voluntary frameworks and recent studies in GHG emission accounting focusing on Norwegian apartment buildings has revealed inconsistencies regarding the life cycle modules, building elements, and functional units. The system boundaries and benchmark values must be aligned with national and international standards, regulations, and best practices, aiming for fair results and knowledge exchange among professionals. Based on data collection and harmonisation, target, reference and limit emission values for new multi-dwelling buildings in Norway that meet national requirements and higher ambition levels have been defined. The three-tiered benchmark system (Target, Reference, Limit) can be utilised by apartment block designers throughout the building process, and can serve as a practical reference for policymakers when setting national benchmark values. Climate targets and policy objectives for 2030 and 2050 require various reduction strategies, from optimising building design to employing low-carbon materials and low-energy solutions. These measures involve a comparison of alternatives across different functional units and the use of simulation technologies to evaluate sustainable design options from the conceptual stages.