The construction sector is responsible for 40% of carbon emissions, 14% of water consumption and 60% of waste production in the world, generating a state of unsustainability. In order to keep these values under control and make the most sustainable choices starting from the earliest stages of building design, a Life Cycle Assessment (LCA) can be used. This consists of an analysis of the environmental impacts of a product, activity or process throughout all phases of the life cycle. The fundamental problem of implementing this analysis process in the construction sector is the difficulty in managing the fragmented building information that covers all aspects of buildings life stages in an integrated way. The Building Information Modeling (BIM) approach offers the possibility of managing a complex information system in an integrated manner. The BIM-LCA integration solutions proposed in recent years made LCA analysis faster, cheaper and usable by more professionals. This paper proposes an analysis of the state of the art of the research published in the last ten years regarding the integration of BIM-LCA as a methodology whereby the BIM approach can support and simplify data management for LCA analysis. The aim was to present the work methodologies tested so far and to describe all the factors that were considered in applying the BIM-LCA integration. The novelty of this review consists of identifying a series of more recurrent parameters and measures used by most researchers deriving a trend of possible and consolidated workflows. The result is, therefore, to present evidence of a general heterogenous framework and to define the common and widespread approaches identifying the main features.

The European Directive on Energy Efficiency in Buildings (Directive 2010/31/EU) has introduced the need to transform buildings to nearly zero energy (NZEB) by 2020. Existing buildings represent the major part of the building stock and an interesting challenge is to transfer it toward NZEB. Energy retrofit is even more significant in Italy, where existing buildings stock (mainly residential) is also historic, so it's subject to environmental constraints or architectural-artistic value, and it's influenced by specific regulations and methods of intervention for refurbishment. In this case, the challenge becomes even more important and concerns both the building shell and the systems: retrofitting introduces not originally present in the complex; retrofit is not covered in the maintenance, since it represents an upgrade, an adaptation of the building, specifically in relation to energy efficiency, but also, by extension, other functions / features pertaining to the environment and sustainability. A case study of a radical refurbishment of an historical building is Ca’ S. Orsola in Treviso. It is ruled by the Historical and Architectural Veneto Regional Authority. The building has been transformed into a prestigious residential complex by a major renovation that was aimed primarily seismic and energy upgrading. The energy and environmental performance of building have been analyzed by numerical simulation and experimental measurement in the EBC IEA Annex 56 [1] context with the aim to verify that intervention strategies respect to the reduction of energy consumption, the minimization of CO2 emissions and maximizing the use of sources of renewable energy

The energy policies of the European Union (EU) encourage the member states to convert building stock into nearly Zero-Energy Buildings (nZEB) and national public authorities to adopt exemplary actions. Directive 2010/31/EU (EPBD recast) introduces the concept of nZEB as a building that has a very high energy performance and its energy need is covered to a very significant extent by energy from renewable sources (RES). Moreover the Directive refers to the cost-optimal methodology for fixing building energy requirements.\ud \ud This paper presents the results of the application of the cost-optimal methodology in a couple of existing school buildings located in the North East of Italy. The analysed buildings are a primary and a secondary schools that differ in construction period, in compactness ratio, in buildings envelope materials and systems. Several combinations of retrofit measures have been applied in order to derive cost-effective efficient solutions for retrofitting according to the methodology proposed by the project Annex56 “Cost Effective Energy & CO2 Emissions Optimization in Building Renovation”. The cost-optimal level has been identified for each building and the best performing solutions have been selected considering a financial analysis and the application of “Conto Termico 2.0” government incentives. The results show the suitability of the proposed methodology to assess cost-optimality and energy efficiency in school building refurbishment. Moreover, this study shows different possibility providing the most cost-effective balance between costs and energy saving