To reduce global warming the emission of greenhouse gases (GHG) must be net zero in 2050, Paris agreement. In the Netherlands the building sector is responsible for 38% of total GHG emissions, 27% being operational carbon (related to energy use) and 11% embodied carbon (related to the use of materials). A large portion of the GHG emissions in this sector originates from existing residential buildings and is for the majority related to energy for heating.

Renovating existing buildings is a key step in reducing operational carbon emissions related to heating. Due to the environmental advantages of renovation, it acts as the first step to reduce carbon emissions. The general strategy to reduce carbon emissions, first focuses on the operational carbon by transitioning from non-renewable depletable energy sources to renewable, sustainable energy sources, also known as the energy transition, starting with replacing natural gas for heating and cooking. In the Netherlands the target is to reduce 49% of GHG emissions compared to 1990 by 2030, and 95% by 2050. In practical terms this requires a renovation of 1.5 million residential buildings by 2030 and 5.5 million residential buildings by 2050.

As operational carbon decreases, reducing the embodied carbon becomes more important. Unlike operational carbon which is only present during the in-use stage of a building, the embodied carbon is present in all stages of a building’s life cycle. Clear standards on the assessment of carbon emissions over the full life cycle of a building are missing. Due to this current strategies are not selected to reduce carbon emissions on the complete spectrum of carbon emissions. The risk is that the overall carbon reduction of the building stock is less than expected.

Renovation changes the life cycle of a building and thus its long term performance. Renovations with high energy saving often can’t be performed in a single step due to high investment costs. Therefore renovation is often executed in multiple steps. Understanding the effects of different use-phase scenarios can help reduce carbon emissions on the long term.

Furthermore, assessing the performance of all generated renovation solutions, at an early design stage, can be time consuming and requires a high level of information. This limits the number of renovation options explored and indirectly influences the effectiveness of a renovation.

The aim of this thesis is to investigate how assessment of renovation strategies can be simplified to support decision making in renovation. The thesis investigates different renovation strategies and scenarios for the in use stage of a terraced house, to improve decision/making in renovation, by looking at the level of renovation, renovation measures, renovation execution and decision making criteria. The data gathered is used to create a tool, supporting decision-making for renovation strategies. Data is obtained using various tools, and by performing among others a simplified Life cycle analysis (LCA) and life cycle costs (LCC) assessment. The performance of the renovation strategies are evaluated based on energy performance, environmental performance and costs.

The built environment is a major consumer of energy in which many improvement steps have to be made. This project investigates how energy can be more efficient by reducing, reusing and producing energy on an urban and building scale. The research showed that the implementation of a sustainable collective heating system around the Palace of Justice can significantly reduce the energy consumption for heating. Comprehensive renovations improving the building energy performance reduce the energy consumption to a minimum. The proposed sustainable integrated renovation of the Palace of Justice shows what such renovation can look like. The combination of modern sustainable techniques and more common interventions opens up the traditional approach to energetic sustainability resulting in a monumental nearly zero energy building. With its role as an energetic catalyst, the addition of public functions and the increase of accessibility, the Palace of Justice is firmly embedded in the city and society and can therefore last for many years to come.

There is growing consensus around the world for the need to transition to a more sustainable society. This is transition is currently being led by making the energy sector more sustainable by shifting to renewable energy sources from fossil fuel sources at a steady pace. However, there seems to be increasing recognition that the steady pace may not be fast enough. Therefore, there are many cities, countries, organizations that are coming out in support of a 100% renewable energy transition. There is sufficient attention given to this the endeavour of transitioning in developed nations and major developing nations. However, Small Island Developing States (SIDS) have historically lagged behind in proceeding with this transition even though they are arguably going to be the most severely affected by the inaction. Majority of SIDS energy comes from imported oil products. As we speak there are islands disappearing because of sea level rise. That said islands present an interesting geographical scope to analyse for an energy transition because of their unique challenges. These challenges stem from their isolated location and small size; which leads to high energy prices, lack of economy of scale and this is worsened by their potential vulnerability to environmental catastrophes. In recent years, however, there has been more attention given to SIDS and their issues. This is marked by Fiji being the President of COP23, and the COP23 paying special attention to SIDS. Following this recent surge in attention, many islands have set ambitious targets to pursue for the transition yet their execution has been bleak. It is astonishing that even though islands have the most renewable energy potential they have made limited progress, literature very widely states that the lack of economy of scale, technical knowledge and expertise, political will and lack of human capacity are leading causes and all of this leads to a larger risk perception leading to lack of investments. However the literature on islands transitioning is concentrated on either on a combination of technological, economical or societal issues and is geographically concentrated on the Pacific and Mediterranean islands.