Energy retrofits can be executed by a building owner with or without the supervision of a third-party agent. We define process models to capture third-party energy retrofit inspection activities, and refine, augment, and generalize those models to then examine the impact of third-party retrofit inspections. Buildings included in the study vary considerably in type, and so do retrofit programs applied to those buildings.

The world is experiencing increasing energy usage owing to environmental impacts suchas climate change, Ozone layer depletion, and global warming. Energy usage is primarily categorized into transport, industrial, residential, and service sectors, with the transportation and industrial sectors taking up a considerable chunk of the energy use; Buildings partly determine the use of energy globally. This review presents a critical analysis of energy demand and uses in the building sector considering the energy optimization for The Church of Jesus Christ of Latter-day Saints in Trollhättan, including the local energy requirements. The modelling software IDA-ICE isused to conduct simulations for different scenarios. The IDA-ICE software links the actual building images with the isometric views done on a computer. The energy balance of buildings is considered with respect to the three methods for heat transfer, the U-value,ventilation, heating load, and cooling load. The study results show that the building relieson electricity and fuel for its energy supply and that fuel consumption takes the highest share, 60 %. Retrofit 1 (where the oil and electric boilers are replaced by geothermal heat pump with COP 4 for heating and domestic hot water), Retrofit 2 (which keeps changes from Retrofit_1 and where a new AHU with a VAV system replaces the existing two AHUs), and Retrofit 3 (which keeps changes from Retrofit_2 and only connects the heating system to district heating) are designed as part of the findings to understand the variation sin comfort reference, supplied Energy, used Energy, utilized Energy, auxiliary Energy, and the Energy of all zones during heating and cooling. The model results indicate that Retrofit2 demonstrates better results than the other two since it has a higher energy-saving capacity. The energy reduction for Retrofit model 1 is about 33.4 %, while Retrofit model 2 has 55% and model 3 has 33%, significantly decreasing the associated costs. The LCC analysis shows payback for the first model 6.73 years with an investment cost of 700 000 SEK, the second model has 5.84 with 1 million SEK investment, and the third model has 3.4 years with 350 000 SEK.

The global share from buildings towards energy usage in residential and commercial buildings have been increasing constantly reaching between 20% to 40% in developed countries and has overtook the other major sectors: industrial and transportation. Energy demand reduction in the building sector is important for Sweden to achieve national energy aims for reduced energy use in the future.  For this reason, energy efficiency measures in buildings today is one of the main objective for energy policy towards 2020 goals.   This project moves on the same path to find energy efficiency potential in Fridhemsskolan buildings in Gävle, Sweden by performing energy audit using IDA-ICE software to simulate energy performance for the buildings under study. In addition, measurements have been made on three of the school buildings named Hus 1, Hus 2 and Hus 3.   The results include different energy efficiency retrofits on each building and economic analysis of these retrofits for each building individually and for the whole buildings together. The presented measures are reducing working hours of the ventilation system in Hus 2, change of CAV system with VAV system in (Hus 1 and Hus 2) and lights changing to LED, s efficient lights and building envelope improvement which includes walls and roof extra insulation and windows replacement.   Replacement of the CAV system in Hus 1 and Hus 2 were not economically beneficial when considering their high cost compared to energy reduction that can be achieved by applying them. On the other hand, energy retrofits analysis showed that combination of the following energy efficiency measures is the most effective and profitable: extra insulation (walls and roof), windows replacement and lights change to LED in the three buildings. In addition to these measure is reducing running hours of the ventilation system in Hus 2.   Implementation of the recommended energy efficiency measures will save 120, 737 kWh/ year of the district heating and 21, 962 kWh/year electricity consumption with capital investment of 417, 396 SEK and 98, 957 SEK/ year cost saving with payback period of 4.2 years. These figures represent 40.3% and 18.1% reduction in district heating and electricity energy use respectively.   Since reducing working hours of ventilation system measure has no capital investment and have the highest figure of energy reduction it reduces payback period significantly. In case the amount of money saved by this measure doesn’t consider; payback period for the other measures which require capital investment will be 13.5 years and the energy saving in terms of cost will be 30, 874 SEK/ year.

La réduction de la consommation énergétique du secteur résidentiel constitue un enjeu majeur dans un contexte de transition énergétique et de lutte contre le changement climatique. Pourtant, malgré les politiques publiques en place, la consommation énergétique sectorielle française peine à baisser. À travers quatre essais empiriques, cette thèse s’intéresse aux obstacles à la baisse des consommations énergétiques dans le secteur résidentiel français en se focalisant sur le rôle des facteurs individuels. Dans le premier chapitre, qui s’inscrit dans la littérature sur le les barrières à l’investissement en efficacité énergétique et le « paradoxe énergétique » (Jaffe and Stavins, 1994), nous utilisons la méthode des choix discrets pour mettre en évidence le rôle de l’incertitude sur la qualité des travaux de rénovation et le prix de l’énergie comme barrière à l’investissement en efficacité énergétique. Le second chapitre fournit un éclairage empirique sur le rôle des facteurs socio-économiques, des préférences individuelles pour le confort et de la performance énergétique du logement pour expliquer la consommation énergétique résidentielle. Le troisième chapitre est l’occasion d’étudier l’écart de performance énergétique à l’échelle du logement (consommation énergétique réelle vs théorique) et ses déterminants individuels et socio-économiques, via la régression quantile. Enfin, le quatrième chapitre s’intéresse aux interactions dynamiques entre efficacité énergétique et consommation énergétique en traitant la question de l’effet rebond direct pour l’usage de chauffage résidentiel en France. / Reducing the energy consumption of the residential sector is a major stake in the context of the energy transition and the fight against climate change. However, despite the implementation of several dedicated public policies, the energy consumption of the sector has barely decreased in France. Through four empirical articles, this thesis aims to identify some of the barriers to the decrease of the French residential energy consumption with a focus on the role of individual determinants. In the first chapter, we wish to contribute to the literature on the barriers to energy efficiency investment (Sutherland, 1991) and the “energy efficiency gap” (Jaffe and Stavins, 1994). We use the methodology of the discrete choice experiment to assess the role of perceived risk and uncertainty on retrofit quality and energy price as barrier to the energy renovation decision. In the second chapter, we provide an empirical contribution on the role of individual preferences for comfort, other individual determinants and energy performance of dwellings in explaining energy consumption. In the third chapter, we study the energy performance gap (gap between theoretical and real energy consumption at dwelling level) and its drivers by using the quantile regression. Finally, in the fourth chapter, we test the assumption of the existence of a rebound effect for the heating energy consumption in France.