abstract: In this era of high-tech computer advancements and tremendous programmable computer capabilities, construction cost estimation still remains a knowledge-intensive and experience driven task. High reliance on human expertise, and less accuracy in the decision support tools render cost estimation error prone. Arriving at accurate cost estimates is of paramount importance because it forms the basis of most of the financial, design, and executive decisions concerning the project at subsequent stages. As its unique contribution to the body of knowledge, this paper analyzes the deviations and behavior of costs associated with different construction activities involved in commercial office tenant improvement (TI) projects. The aim of this study is to obtain useful micro-level cost information of various construction activities that make up for the total construction cost of projects. Standardization and classification of construction activities have been carried out based on Construction Specifications Institute’s (CSI) MasterFormat® division items. Construction costs from 51 office TI projects completed during 2015 and 2016 are analyzed statistically to understand the trends among various construction activities involved. It was found that the interior finishes activities showed a much higher cost of construction, and a comparatively higher variation than the mechanical, electrical, and plumbing (MEP) trades. The statistical analysis also revealed a huge scope of energy saving measures that could be achieved in such TI projects because of the absence of energy management systems (EMS) found in 66% of the projects. / Dissertation/Thesis / Masters Thesis Construction 2016

During the last decades the real estate and construction industry has experienced a major development regarding sustainability aspects. However, something that is often neglected when discussing sustainability within the real estate sector is the process of adapting office spaces for new tenants, in which current practice implies that perfectly fine materials are demolished and thrown out due to aesthetic demands from tenants. The purpose of this study was therefore to examine how interventions should be constructed, by the application of the theory of nudge, to influence office tenants to favor reuse instead of new materials within the process of tenant improvements. By identifying the four most crucial factors of decision-making regarding reuse from semi-structured interviews with business professionals within the real estate sector, statements were constructed and rated by individual tenants according to the seven grade Likert scale in a self-administrated questionnaire. The questionnaire was distributed to tenants within a property portfolio twice, before and after the tenants took part in a printed intervention in a digital format. The intervention was constructed as an information sheet concerning reuse and included four chosen tools of nudge with the purpose of positively affecting the respondent’s attitude towards reuse. By distributing the same questionnaire, the change in rating between the two questionnaires could be observed, presenting the effect of the intervention. The ratings were analyzed by a conceptual analysis of an independent-sample T test in SPSS comparing the mean values as well as additional analyses of rating distribution in Microsoft Excel. The results showed a minor, but not significant change in mean values but a noticeable change in rating distribution, especially regarding the neutral rating of 4. The intervention was able to affect the respondents both in a positive and negative manner, which indicates that there is a major knowledge gap which can be reduced by the implementation of the nudge theory. The study concludes that there are many challenges regarding the practice of reuse where landlords and tenants need to cooperate to create a practice aiming towards a more sustainable process of tenant improvements. / Under de senaste årtiondena har det skett en stor utveckling i bygg- och fastighetsbranschen gällande hållbarhetsarbete. Något som däremot inte tas i beaktning när hållbarhet diskuteras inom branschen är processen vid hyresgästanpassningar där nuvarande arbetsmetod innebär att fullt fungerande material rivs ut och slängs på grund av de estetiska krav som hyresgäster ställer. Syftet med denna studie var därför att undersöka hur interventioner kan konstrueras genom att applicera nudge-teorin för att positivt påverka hyresgästers attityd kring återbruk vid hyresgästanpassningar. Genom att identifiera de fyra mest avgörande faktorerna vid beslutsfattandet kring återbruk med hjälp av semistrukturerade intervjuer med yrkesverksamma respondenter inom fastighetsbranschen, kunde frågor i form av påståenden skapas och mätas av individuella hyresgäster i enlighet med en sjugradig Likertskala i en självadministrerad enkät. Enkäten distribuerades till hyresgäster i en fastighetsportfölj vid två tillfällen, en gång innan och en gång efter det att respondenterna tagit del av en tryckt intervention i digitalt format. Interventionen konstruerades som ett informationsblad om återbruk och innehöll fyra utvalda nudge-verktyg vars syfte var att positivt påverka respondentens attityd till återbruk. Genom att distribuera samma enkät två gånger kunde skillnaden i rankning mellan de två enkäterna utläsas för att mäta effekten av interventionen. Utfallet av enkätstudien analyserades med en konceptuell analys genom ett t-test i SPSS där medelvärdet av de olika faktorerna jämfördes. Förutom detta gjordes kompletterande analyser avseende svars-distributionen i Microsoft Excel. Resultatet påvisade endast en liten, men inte statistisk signifikant, skillnad i medelvärde medan en observerbar skillnad kunde utläsas i svars-distribution, speciellt gällande den neutrala graderingen 4. Interventionen lyckades påverka respondenter både positivt och negativt, vilket påvisar ett stort kunskapsglapp som kan minskas med hjälp av nudge-teorin. Studien påvisar att det finns många utmaningar avseende återbruk där hyresvärdar och hyresgäster måste samarbeta för att skapa ett arbetssätt som främjar utvecklingen kring hållbarhet vid hyresgästanpassningar.