Creative Commons

This dissertation was written as a part of the MSc in Energy Systems at the International Hellenic University. Compared to dwellings, non-domestic buildings tend to have higher energy consumption per square meter of floor area. Office buildings consume a lot due to the fact that they have special characteristics that enhance this problem. Lighting, IT equipment and air conditioning systems are considered main reasons for steeply rising energy consumption in office buildings. Moreover, in the last decades the buildings have spatial characteristics that provoke more energy consumption through their usage (glazed facades etc.). Nowadays, the rate of new constructions is rather limited, mainly due to financial reasons. Hence, refurbishment of existing building stock is an intense necessity in the urban environment. New policies are adopted from EU in order to improve energy efficiency of non-residential buildings. This effort has given a new perspective to the re- development of the construction sector of the economy. This dissertation provides a methodology to face current problems of existing office buildings, the first renovation measures, restoration of facades, replacement of HVAC and lighting systems with the primary goal of minimizing energy consumption by implementing passive design techniques with RE Systems in order to correspond to standards of building that consume as little energy as possible .The end goal of high energy performance can be achieved by using passive solar building design(enabling the building to collect solar heat in winter and reject solar heat in summer) thus using alter-native methods of energy production. To conclude, a case study of refurbishment of an existing office building in Thessaloniki is formed.