Climate analyses point the way to halved emissions

Stockholm Royal Seaport aims to halve the climate impact of construction and civil works by 2030. To succeed, the City of Stockholm needs to know where emissions arise and which measures have the biggest effect. By systematically calculating climate impact and testing new solutions, methods are being developed that both reduce emissions and can cut costs.

Climate calculations for buildings

As early as 2012, Stockholm Royal Seaport began to require climate calculations for buildings, which produced varying results and made clear the need for a common approach so that comparisons could be made. Ten years later, both limit values and a unified methodology were in place, developed together with the municipal housing companies. At the same time, requirements for climate calculations were introduced for the city’s own projects. To make the work easier, a simplified model was developed based on the Swedish Transport Administration’s climate calculation tool. This means more projects can analyse their climate impact early on and that the results are more consistent and comparable.

Climate calculations at the design stage have been reported for eleven buildings. Apartment buildings range between 258 and 461 kg CO₂e/m² GFA, which can be compared with the reference value^* of 311 kg CO₂e/m².

Reference values for climate impact when constructing buildings, version 3 (2023). Tove Malmqvist (KTH), Sara Borgström (WSP), Johanna Brismark (KTH), Martin Erlandsson (IVL Swedish Environmental Institute). Climate impact for building parts 2–8 and the construction stage (A1–A5), with system boundary according to the 2027 climate declaration.

Climate calculations for public land

To better understand the climate impact from streets, parks and other public land, the city carried out calculations of several completed detailed development plans in 2024. The results show that climate impact varies sharply with ground conditions. The more complicated the foundation work, the larger the emissions. Concrete and steel account for the largest share of climate impact – in some cases up to 95 per cent. Experience clearly shows that the climate issue needs to be raised early in the detailed planning stage, when there is still scope to influence design and choices.

During 2025, four climate calculations with action plans were carried out at the design stage. In parallel, eight contracts within the Södra Värtan climate analysis were calculated. In the Saltkajen contract, concrete was replaced with crushed material and climate-improved concrete was used. The measures cut emissions by 2,200 tonnes CO₂e and produced cost savings of around SEK 2 million. The project received the Swedish Concrete Association’s climate prize in 2025.

Climate analysis of detailed development plans is the important piece of the puzzle

To identify opportunities to reduce climate impact from the built environment as early as possible, climate analyses already at the detailed development plan stage are needed. The analyses make visible which facilities and measures drive the greatest climate impact and provide a basis for further work at the design stage, where structures and technical solutions are optimised. In procurement, targeted climate requirements are then placed on selected materials and execution methods.

A climate analysis for the Södra Värtan sub-area was completed in 2025. Because implementation work in the area began as early as 2016, the analysis covers completed, ongoing and projected contracts as well as an area that has not yet been designed. The climate analysis shows that material use – primarily steel and concrete/cement – accounts for just over 90 per cent of climate impact in all contracts.

A climate analysis was also prepared for Ängsbotten in 2025. The results show that ground-strengthening measures account for a large share, and measures will need to be taken in the continued design work.

Sustainability Report 2025: Climate

Innovation project: Climate calculation at the detailed development plan level

Planning for reduced climate impact (in Swedish)

Challenges

The work shows that concrete and structural steel account for a large share of climate impact, with the following challenges:

• Design standards are conservative and lead to high material use.
• The city’s technical handbook needs to take the climate issue into account.
• Climate-neutral cement requires CCS technology, which entails the risk of limited supply and higher costs.
• Structural steel is a broad product group, which makes it difficult to set clear requirements.
• Climate analyses are not always carried out early enough, which reduces the scope to influence design and can lead to higher costs.

The way forward

To continue reducing climate impact, Stockholm Royal Seaport focuses on:

• Strengthening cooperation between the city’s departments, property developers, academia and other cities.
• Continuing to set requirements in procurement to promote low-climate-impact solutions.
• Testing alternative materials at full scale – for example, replacing reinforcement bars with basalt rods.
• Updating limit values in land allocations and procurement.
• Ensuring that the climate perspective is factored into every investment decision.