The construction industry is currently responsible for a large amount of greenhouse gas emissions that contribute to the enhanced greenhouse effect. In hopes of facilizing a sustainable development, a new law came in force 2022 requiring climate declarations for new construction projects. This requirement means that construction companies around the country must climate calculate for their construction projects. Among these companies is Akademiska hus, a property management company that strives to become a carbon neutral operation. The thesis was conducted in collaboration with Akademiska hus to investigate how the method of climate calculations can be made more effective. The study was conducted through an interview and a case study of two different projects, Solna Campus Office and Retzius Laboratory. The aim was to identify which part of the process that needs to be made more efficient, and then to develop a solution proposal. The calculation tools Prodikt and One Click LCA were then tested to measure the carbon footprint of the projects, and standard value data was developed. The result from the interview study showed that the problem lies in the lack of a clear method for collecting input data, but that the calculation tools Prodikt and One Click LCA can facilitate the streamlining of climate calculations. The results from the case study shows that the carbon footprint for the projects was measured to, internal wall: 7.21 kgCO2e/m2construction, ceiling: 3.23 kgCO2e/m2 material internal floor: 9.58 kgCO2e/m2 material, wall cladding: 14.18 kgCO2e/m2 material, parts of the ventilation system for Solna Campus Office: 1.12 kgCO2e/m2gross floor area, parts of the ventilation system for Retzius Laboratory HG6: 14.4 kgCO2e/m2gross floor area. Furthermore, it is concluded that these values can be used as standard value data for reconstruction projects under 50 MSEK of office and laboratory environments at Akademiska hus. The conclusion was drawn that if standard value data is developed for reconstruction projects under 50 MSEK, the method of climate calculations will be made more effective.

Ett byggprojekt använder idag cirka 21% av den tid som finns tillgänglig och står under den övriga tiden stilla. Samtidigt beräknas ungefär en tredjedel av arbetsdagens timmar försvinna som slöseri. En optimal situation hade inneburit ett 100% nyttjande av den tillgängliga tiden vilket i sig kunnat innebära en ökad effektivitet. Tidsanvändningen inom ett projekt påverkar resursanvändningen, där resursen arbetskraft idag motsvarar mellan 10–60% av den totala projektkostnaden. Planeringen av den tillgängliga tiden görs med hjälp av tidplaner och arbetsplatsens arbetstider blir styrande vid upprättandet av en tidplan. Genom att förändra arbetstiderna så förändras nyttjandegraden av den tillgängliga arbetstiden vilket möjliggör för en ökad effektivitet inom ett byggprojekt. Syftet med den genomförda studien har varit att undersöka vilka hinder och drivkrafter som finns för en förändring av de nuvarande arbetstiderna vid ett byggprojekt. Fokus har varit ett valt ombyggnadsprojekt i Stockholm. Målet med studien var att genom en kartläggning och identifiering av faktorerna bidra till en ökad förståelse och kunskap inom området samt redogöra för de interna förutsättningarna som bör finnas för en förändring av arbetstiderna. För att besvara syftet genomfördes en utforskande abduktiv fallstudie. Genom workshopar och intervjuer inhämtades primärdata direkt från fallprojektet, samtidigt som en litteraturstudie genomfördes med utgångspunkt i vad som framkommit av studiens inledande del. I slutskedet genomfördes en simulering av fallprojektets tidplan för två valda aktiviteter där den ordinarie arbetstiden ersattes av skiftarbete och en utökad arbetstid i form av en 7-dagarsvecka, med syftet att teoretiskt testa en arbetstidsförändring. Förändringen visade på en minskning om 43% respektive 19% av den totala kalendertiden. Resultatet från studien visar att det finns 15 stycken faktorer som påverkar eller påverkas av att arbetstiderna skulle förändras vid byggprojektet. Faktorerna kan ses som antingen drivkrafter eller hinder, där de interna drivkrafterna antingen kan ses som incitament till en förändring eller som resultat av förändringen. De interna drivkrafter som identifieras i studien är kontraktshandlingar, förseningar, arbetsmetoder, projektets utgifter samt produktionstid/tid för färdigställande. Interna hinder som identifieras ses som svårigheter och hindrande faktorer. Dessa faktorer identifieras som projektorganisationen, informationsöverföring, personalutrymmen, säkerhet, administrativa arbetsuppgifter samt arbetsplatslogistik. Som externa hinder identifieras arbetstid och arbetstidslagen, kollektivavtal, lönemodeller och lokala regler inom Stockholm stad. De interna förutsättningarna som bör finnas för en implementering av förändrade arbetstider är en tidig förankring mellan delaktiga parter, att arbetsplatsens kapacitet fastställs med avseende på resurserbehovet samt att implementeringen regelbundet följs upp. Studien indikerar på att man genom dessa tre insatser kan ge ett projekt de rätta förutsättningarna till en framgångsrik implementering av förändrade arbetstider. Slutligen rekommenderas fallföretaget att fortsatt utvärdera behovet av dagens arbetstider samt hur behovet av en arbetstidsförändring ser ut, eftersom studien indikerar på att det finns fördelar för ett projekt med helt eller delvis förändrade arbetstider i produktionen. / A construction project today uses about 21% of the time that is available and stands still for the rest of the time. At the same time, it is estimated that about a third of the working day's hours will disappear as waste. An optimal situation would be a 100% utilization of the available time, which could mean increased efficiency. The use of time within a project affects the use of resources, where the labor costs today corresponds to between 10–60% of the total project cost. The planning of the available time is done with schedules and the workplace's working hours become governing when establishing a schedule. By changing working hours, the utilization rate of the available working hours changes, which enables increased efficiency within a construction project. The purpose of the completed study has been to investigate the obstacles and driving forces that exist for a change in the current working hours of a construction project. The focus has been on a redevelopment project in Stockholm. The aim of the study was to contribute to an increased understanding and knowledge in the area through a mapping and identification of the factors and to account for the internal conditions that should exist for a change in working hours.  To answer the purpose, an exploratory abductive case study was conducted. Through workshops and interviews, primary data were obtained directly from the case project. Meanwhile a literature study was carried out based on the introductory part of the study. In the final phase, a simulation of the case project's schedule was carried out for two selected activities where the regular working hours were replaced by shift work and an extended working hours in the form of a 7-day week, with the aim of theoretically testing a change in working hours. The change resulted in a reduction of 43% and 19% of the total calendar time.  The results show that there are 15 factors that affect or are affected by the fact that working hours would change during the construction project. The factors are either driving forces or obstacles, where the internal driving forces can either be incentives for a change or as a result of the change. The internal driving forces identified in the study are contract documents, delays, working methods, project expenses and production time/time for completion. Internal barriers that are identified are difficulties and hindering factors. These factors are identified as the project organization, information transfer, staff spaces, security, administrative tasks and workplace logistics. Working hours and the Working Hours Act, collective agreements, wage models and local rules within the City of Stockholm are identified as external obstacles. The internal preconditions that should exist for an implementation of changed working hours are an early anchoring between the parties involved, that the workplace's capacity is determined regarding the need for resources and that the implementation is followed up regularly. The study indicates that through these three initiatives one can give a project the right conditions for a successful implementation of changed working hours.  Finally, the company is recommended to continue evaluating the need for current working hours and what the need for a change in working hours looks like, as the study indicates that there are benefits with completely or partially changed working hours in production.

In 2020, Sweden´s construction industry generated approximately 14.2 million tons of construction and demolition waste, accounting for around 40 percent of the country´s total waste, excluding mining waste. Sweden aims to ensure that at least 70 percent of construction demolition waste should be prepared for reuse, recycling, or other recovery by 2025. However, the recycling rate in 2020 was 52 percent. Sweden's Circular Economy Action Plan highlights the potential to increase recycling in the construction sector. A majority of the renovation projects are the renovation of houses built between1965-1974. Houses built during this period are called the Million Program (Swedish:miljonprogrammet). These projects face a significant waste management challenge due to higher amount of waste, more materials, limited construction sites and housing, and absence of elevators. This thesis was conducted throughout interviews and a case study at Kvarteret Rackarberget, an innovation project in Uppsala, with NCC as the construction contractor. The purpose was to investigate material recycling in residential refurbishment in Sweden and identify challenges. The purpose was also to evaluate possible improvements to increase the proportion of construction waste that is recycled. The results indicate that increasing material recycling requires a higher rate of sorted waste, with significant potential for improving the sorting of plastic. To achieve a higher rate of sorted waste, the amount of combustible waste needs to be reduced by sorting materials to a waste container. Suggested improvements include better cooperation between construction and waste contractors, enhanced logistics at the construction site, and improved communication among all stakeholders. Achieving these improvements requires a strong willingness and commitment.