Cumulative climate impact of repeated tenant adaptations

Abstract

When greenhouse gas emissions in the building sector are considered, the focus is often on new construction. However, this is not the whole picture. Existing commercial buildings, such as office buildings, also go through several changes during their lifetime, and these changes can have a relevant climate impact. In office buildings, such changes are often called tenant adaptations, where the interior space is adjusted for current or future tenants. This can include changes to floors, interior walls, finishes, painting, installations, ventilation, and other building elements. A single tenant adaptation may seem small compared with a new building, but repeated adaptations can add up over time. Since climate thresholds and climate declaration requirements mainly address new construction, the climate impact of tenant adaptations is not controlled in the same way.
This thesis studies these issues by analysing the climate impact of tenant adaptations in office buildings. The study is based on project data provided by Wihlborgs Fastigheter AB and includes 27 tenant adaptation projects and two new construction projects used as reference cases. The analysis focuses on climate impact and material mass intensity for modules A1–A5. These modules were selected since they are used in the Swedish climate declaration approach.
The study examined how tenant adaptations can be classified by depth and material mass intensity was used for this calculation. Material mass intensity can give an indication of how much material is changed in each project, meaning that a higher material mass intensity can suggest a deeper tenant adaptation.
Based on the results, proposed threshold values were developed for light, moderate, and deep tenant adaptations to support better control of their climate impact. Several scenarios were developed. These included scenarios based on adaptation depth, a reuse and recycling scenario, and scenarios using the proposed threshold values for tenant adaptations.
The results show that repeated tenant adaptations can exceed the threshold values used for new construction over a 50-year reference study period. The results also show that deep adaptation is not automatically the worst option. A single deep adaptation may have a high impact, but several smaller adaptations can lead to a high cumulative climate impact when they are repeated over time.
This study shows that tenant adaptations should be considered more clearly in building life cycle assessment. Better project data is needed, and threshold values could help limit the climate impact of these projects. Future research should also study tenant adaptations in other contexts and include other aspects, such as cost and practical tools for assessment.

Popular Abstract

When we talk about the climate impact of buildings, the focus is usually on new construction. However, office buildings also go through several smaller changes during their lifetime. When a new tenant moves in, walls may be moved, floors and ceilings may be replaced, and installations may be adjusted. These projects are known as tenant adaptations.
One tenant adaptation may seem small compared with constructing a new building. However, when these changes are repeated several times over many years, the total climate impact can become quite high.
This study examined 27 tenant adaptation projects from Wihlborgs Fastigheter AB. The calculations covered emissions from material production, transportation, construction waste and activities at the construction site.
One of the main challenges was that the climate impact alone does not show how extensive a project was. A small project may have high emissions because materials with a high climate impact were used. At the same time, a larger project may have lower emissions because better materials were selected. Therefore, a classification system was developed based mainly on the amount of material used per square meter.Each project was divided into different building element categories, such as room formation, interior finishes and installations. The amount of material used in each category was assessed, and the projects were then classified as light, moderate or deep adaptations.
The emissions were also examined over a 50-year service life, where tenant adaptations were assumed to be repeated. The results showed that the emissions can accumulate over time and reach levels that are comparable to the climate impact of constructing a new office building.
Another part of the analysis looked at how the chosen functional unit can change the interpretation of the results. When the values were divided according to the assumed time intervals between the adaptations, the relative results changed. This showed that the same climate impact values can be understood differently depending on how they are presented.
The possibility of reusing materials was also examined. Some walls, ceilings, doors and other components could potentially be reused instead of being discarded. Based on the reuse scenario used in the study, the total climate impact could potentially be reduced by around 17 percent. However, this would require better planning, documentation and careful dismantling.
The study also showed that the quality of the data is important. Missing quantities, inconsistent material categories and the use of generic values make the projects more difficult to compare. A clearer and more consistent system for collecting the data would improve both the calculations and the decisions based on them.
The main conclusion is that tenant adaptations create a climate impact that is often overlooked, even though these projects are repeated throughout the lifetime of an office building. By measuring the depth of each project, improving the data quality, reusing more materials and setting clearer climate targets, the climate impact of future tenant adaptations could be reduced.

• author: Durmaz, Mehmet
• supervisor: Jouri Kanters
• organization: Division of Energy and Building Design
• alternative title: Climate Impact of Tenant Adaptations in Office Buildings
• alternative title: Climate Impact of Tenant Adaptations
• alternative title: The Hidden Climate Impact of Tenant Adaptations in Office Buildings
• course: AEBM01 20261
• year: 2026
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: tenant adaptation, life cycle assessment, embodied carbon, climate impact, material mass intensity, office buildings, building renovation
• language: English
• id: 9242405
• date added to LUP: 2026-06-23 08:08:30
• date last changed: 2026-06-23 08:08:30