Multi-story wood frame construction is a highly relevant topic today because of the need to continue to develop the relatively new building technique to create a sustainable way to keep constructing new buildings. Because the use of wood as a frame material in multi-story buildings is still new, there are still issues that come with the choice to use it. One of these issues is in the detailed technical solutions that are constructed, they often have faults that may lead to problems with moisture. The purpose of this degree project is to investigate these problems and more importantly the process behind constructing them. This work is also examining what can be done to counteract or minimize the issues in the planning phases of the construction as well as look at why it is important to continue developing wood construction. There are two parts of the method used in this degree project. The first part is a literature study which brings up the attributes of wood, factors for using and not using wood, the techniques used to build multi-story buildings in wood, as well as a look into the detailed technical solutions that are used and the planning process behind them. The second part is the interview study where experts in the field are interviewed to get answers about the issues that this work brings up. The interviews provided a lot of information that is relevant for this work and the result consists of the most important answers from them. The biggest factor for continuing to develop the use of wood as a frame material, from the interviews, was about the eco-friendliness of the material. The attitude to use wood in multi-story buildings varies quite a bit depending on which part of the construction sector is asked. The developers are curious but still a bit worried, because of this they have not yet taken the next step in using it more. The entrepreneurs are still sceptical about the use in multi-story constructions and there is not enough knowledge about it for them to earn the same amounts of money as if they were to use concrete or steel. Because of that they are also worried about taking the next step towards using wood more. The consultants, like the architects and construction engineers, are more positive to the use of wood and are inclined to use it more and more. The issues that come up the most are different types of attachments of balconies and exterior corridors, parts that are installed too close to the ground and solutions where the end grain of the wood is in water. There were three main problems that came up repeatedly. The biggest one was the lack of knowledge in the planning and the production phases. The second one was about how there is often no one who looks at the bigger picture in the projects which entails mistakes that could be caught. The last issue was in the installation where the construction workers might not do it according to the construction drawings or a lack of drawings which leads to improvisation at the construction site. Recommended improvements could be a standardisation of the solutions that are proven to work for everyone to use. There is also a need for better communication which provides feedback to the designers of the solutions, that way they will know what to do better in the future. More relevant education within the topic and better coordination will also prove vital in the continued development of multistory wooden constructions.

This thesis presents work around 3 themes: dark energy, gravitational waves and Bayesian inference. Both dark energy and gravitational wave physics are not yet well constrained. They present interesting challenges for Bayesian inference, which attempts to quantify our knowledge of the universe given our astrophysical data. A dark energy equation of state reconstruction analysis finds that the data favours the vacuum dark energy equation of state $w {=} -1$ model. Deviations from vacuum dark energy are shown to favour the super-negative ‘phantom’ dark energy regime of $w {< } -1$, but at low statistical significance. The constraining power of various datasets is quantified, finding that data constraints peak around redshift $z = 0.2$ due to baryonic acoustic oscillation and supernovae data constraints, whilst cosmic microwave background radiation and Lyman-$\alpha$ forest constraints are less significant. Specific models with a conformal time symmetry in the Friedmann equation and with an additional dark energy component are tested and shown to be competitive to the vacuum dark energy model by Bayesian model selection analysis: that they are not ruled out is believed to be largely due to poor data quality for deciding between existing models. Recent detections of gravitational waves by the LIGO collaboration enable the first gravitational wave tests of general relativity. An existing test in the literature is used and sped up significantly by a novel method developed in this thesis. The test computes posterior odds ratios, and the new method is shown to compute these accurately and efficiently. Compared to computing evidences, the method presented provides an approximate 100 times reduction in the number of likelihood calculations required to compute evidences at a given accuracy. Further testing may identify a significant advance in Bayesian model selection using nested sampling, as the method is completely general and straightforward to implement. We note that efficiency gains are not guaranteed and may be problem specific: further research is needed.