life cycle assessment

Energy use in buildings has a significant influence on the global energy demand and environmental impacts. Among all building systems, heating, ventilation, and air conditioning (HVAC) systems are the most energy-intensive in terms of their total energy requirements. The production and operation of HVAC systems have a significant impact on the environment. These systems are also among the largest consumers of natural resources and materials in the building sector.

Increasing insulation thickness may reduce the energy consumption and environmental load in building operation phase, but may also increase those in insulation production phase. Therefore, the life cycle energy consumption and environmental load of insulation design for a typical residential building were analyzed in this paper. Cases in four typical cities -Harbin, Beijing, Shanghai and Guangzhou- in four different climate zones in China were compared.

Green building has come to be a goal of building design now. Since sustainable performance of building involves lots of aspects, an integrated index is needed to evaluate it comprehensively. Building environmental impact assessment (EIA) based on life  cycle assessment (LCA) theory is a well-known method to do this.

Models calculating the environmental benefits of renovation and retrofitting of buildings are generally based on energy calculations and don’t take into account the environmental penalty of demolishing and replacing parts of the building and its equipment.

A methodology was developed to calculate health damages due to exposure to radon emitted to indoor air for use in dwelling life cycle assessment. Fate factors were calculated based on dose conversion factors and effective outgoing airflows. Effect factors were calculated from linear relationship between dose and cancer cases. Damage factors are expressed in terms of disability adjusted life years (DALYs).

Through modeling and computing, life cycle energy consumption (LCEC) and environmentalemission (LCEE) of twelve building materials in production process are analyzed by means oflife cycle assessment (LCA). The inventory analysis includes energy upstream, transportationand production phases. Inventory analysis of energy upstream phase is carried out usingiterative computation, while direct energy consumption and environmental emission, indirectenergy consumption and environmental emission are considered. The outcomes show thatLCA integrated value (16.73) of steel production is the highest.

A life-cycle inventory model for the office buildings is developed in this paper. The environmental effectsof two different building structures, steel and concrete, are intercompared. The results show that thesteel-framed building is superior to the concrete-framed building on the following two indexes, thelife-cycle energy consumption and environmental emissions of building materials.

Life Cycle Assessment (LCA) in many ways is a methodology which building industry is looking towardsto give the answers on how to assess sustainability of buildings. In Hong Kong, like many othercountries, its application is limited by the availability of credible assessment tools in the market. Thispaper provides the details on the processes and findings of a comprehensive study initiated by theGovernment to derive a LCA tool for the use of the local building industry, addressing on researches thatare needed to really make LCA part of the answer to sustainability assessment.

Since most important design decisions are taken during the first design phase, an evaluation ofthe total environmental impact is necessary at that moment. A first step in that direction is takenby the Flemish government through the introduction of the Energy Performance Norm (EPN) fromJanuary 2006 on. The EPN evaluates the overall energy consumption of buildings during the usephase instead of looking at thermal insulation and compactness only.