Thermal bridges increase the building energy demand for heating and cooling. For well insulatedenvelopes and buildings with increased energy efficiency, the influence of thermal bridging on theenergy consumption is of major importance. Here the ratio between the thermal bridging effect and the overall thermal losses increases compared to low or medium insulated buildings and it is possible that the effect of thermal bridges on the energy demand compensates or even overtakes, for instance, the energy gain provided by thermal solar collectors for domestic hot water.

For quite a long time energy conservation and energy efficiency were concentrated on a singlebuilding approach. Until 2000 nearly all national building regulations were based on net energybalances (energy needs) comprising transmission losses, ventilation losses, solar gains, internal gains and heating gains. Due to that the development focused on reduced transmission and ventilation losses, and so-called low energy houses or passive houses were designed and demonstrated in pilot projects, at first for new constructions and later on also for refurbishment projects.

The office building belonging to the Remscheider Entsorgungsbetriebe REB (Waste DisposalUnit in Remscheid), which was constructed in 1968, was thoroughly renovated in 2004. Theutilisation quality was greatly improved with a combination of measures including efficientthermal insulation and solar control, fan-controlled ventilation, better use of daylight andactive use of solar energy for domestic hot water - while the energy consumption valueswere reduced appreciably at the same time.A key aspect of the renovation was to improve comfort during summer without applyingactive air-conditioning.

The ventilation system in nursery buildings requires particular care to guarantee the safety of children[1,2]. When suitable outdoor conditions occur, natural ventilation can provide an appropriate indoorenvironment in terms of temperature, humidity and concentration of contaminants, if the designprocess is coherently developed taking into account the characteristics of the prevailing winds [3].This study investigates numerically the fluid dynamic behaviour occurring in a naturally ventilatedpreschool building designed for the municipality of Rome.

A questionnaire presented to designers demonstrates the difficulty to explain the specific status, thestratification and the correlation of parameters, features, concepts, principles and requirements.

This paper analyzes some important aspects toward changing energy paradigma in urban area.To that aim it is important to act synergically on three sides of the energy system:- Demand side: by reducing energy demand;- Supply side: by optimizing generation system and transmission of energy and by integrating local renewable energy sources also by distributed (co)generation, where it is possible;- Management side: by implementing advanced management control systems able to reduce energy waste and to combine energy demand and generation in the best way.Actions aiming demand containment can affe

One of the topics studied in the European IEE-ASIEPI project (www.asiepi.eu) is the way envelopeairtightness is dealt with in the EPB-regulations of the Member States. To this end, a number of surveyshave been made among the participating countries. Also a quantitative comparison on a samplebuilding has been performed. The results of this study are used in the development of an instrumentto compare the energy performance requirement levels among the Member States.

The emission from materials is an important source of degradation of our indoor air quality. Toinvestigate this field, it is necessary to determine pollutant concentration inside buildings, based onemission rates and air exchange rate (ventilation + envelope airtightness). This paper presentsdifferent method for such determination and their application to the case of formaldehyde from building materials.

Office buildings in central Chile normally show higher cooling than heating energy demand.Overheating is a frequent problem in this type of buildings in cities like Valparaso and Santiago.Santiago (33S) presents a Mediterranean climate, with a high thermal temperature oscillationbetween day and night throughout the year. Valparaso -with a temperate climate influenced by thePacific Ocean- shows lower temperature compared with Santiago.

This study examines the potential for using passive ventilation systems to meet ASHRAE 62.2requirements as a step in the process for optimizing hybrid ventilation systems. A brief review of theliterature with reference to the passive and hybrid ventilation systems in residential building ispresented. The review focuses on key aspects of ventilation system performance, including indoor air quality, air distribution and ventilation rates.