ROT är förkortning till ” Reparation, Ombyggnader och Tillbyggnader ” som ä avsedd för skatteavdrag för vidtagna energibesparande åtgärder inom byggnadsektorn. Syftet med det här examensarbetet är att undersöka olika slags besparingar med hänsyn till dagens befintliga flerbostadshus omständigheter. Byggnadens energianvändning skulle generellt kunna minskas genom att förbättra klimatskal som exempelvis byggnadstekniska åtgärder och utnyttja nya installationstekniska åtgärder bl.a. som FTX ventilation system eller värmepumpar. Med hjälp av IDA ICE energisimuleringsprogram ska två flerbostadshusmodeller byggas. Resultatet från energiberäkningen med IDA ska analyseras och jämföras med bostadshusets energistatus idag. Avsikten med jamförelsen är att anpassa byggmodell för att representera den befintliga byggnaden så gott som möjligt. Förbättringsåtgärder som tillförs i byggmodellen ochberäknas med IDA skulle kunna påvisa olika potentialen av energibesparing. i olika förslagen .Även en ekonomiskbedömning av förbättringsåtgärder med valda åtgärder ska genomföras med ur livscykelkostnadssynpunkt som tar hänsyn till alla kostnader under kalkylperioden. Genom dessa kan fastigheter ägare få överblicka energikostnader för att avgöra ett rimligt och lönsamt beslut om energieffektiviseringsåtgärder. Nyckelord : åtgärder,befintliga flerbostadshus, IDA simulering, livscykelkostnad analys / The building sector accounts for almost one third of total energy use in Sweden. A large amount of residential buildings which were built one half century ago are in urgent need of renovation in order to reduce energy consumption meanwhile improving the inhouse comfort. This paper demonstrates that the heating need of apartment building from 1950s could be lowered by carrying out suggested measures. These include increasing the insulation layers on the roof and external wall, upgrade of windows in the building and reinstallation of ventilation system with heat exchange function. How much heating energy could potentially be cut down by implementation of each measure were examined by constructing and operating the model in the simulation program IDA Indoor Climate and Energy, which takes not only the indoor factors into account but also the external parameters like solar radiation , geographic location and surroundings. Finally the analysis on life cycle cost of each method has been performed based on reasonable assumptions in order to compare these measures in the term of costeffectiveness and give a more complete and sensible picture of energy effective means in the long run. Keywords : apartment building, heating energy reduction buildings envelop, model simulation, life cycle cost analysis, cost effectiveness.

Environmental impact and management of energy is a highly topical issue in today's society. Climate impact must be reduced. The Government has set a target to reduce energy consumption in buildings by 20 % by 2020 and 50 % by 2050 compared to the energy use in 1995. With this in mind, we chose to examine how property owners can work on improving energy efficiency in existing apartment buildings. We also wanted to investigate profitability of different increasing energy efficiency measures and the calculation methods and the risk assessment performed by such investments. To tie in with government objectives, we also saw the possibilities of achieving these goals. 20 companies were interviewed, of which 14 were property owners and 6 were consulting firms that works with energy efficiency. All property owners were familiar with the importance of energy work but they worked very different with it. The interviewed companies work with energy efficiency measures in the building envelope, HVAC , household and residential electricity and solar energy. The companies have chosen to implement various extensive measures and outcome measures differ between objects of different conditions. Also the choice of calculation method for the calculation varied between companies. Much of the results were due to the tradition and resources. Many of the larger companies have come a long way in their work toward the energy targets and some already achieves the goals by 2020. Others are not as advanced, because they do not see sufficient profit to invest in energy efficiency measures.