Unit 2: Sustainable Construction Embodied Energy Learning Outcome To gain an understanding of Embodied Energy in buildings from extraction of raw materials to finished product, transportation and the completed building. Tutor: Dr A Kimmance

What is Embodied Energy? * Embodied energy, also known as embedded energy is the energy consumed by the processes associated with the production of a building: * from the mining of raw materials and processing of natural resources to manufacturing, transport and product delivery. * The total sum of the energy requirements associated, directly or indirectly, with the delivery of a good (item) or service. * In practice however there are different ways of defining embodied energy depending on the chosen boundaries of the study. * The three most common in construction practise are: –cradle-to-gate: embodied energy of individual building components –cradle-to-site: energy required to produce the finished product –cradle-to-grave: energy consumed by the life of a building

Embodied Energy Consumption * Initial embodied energy: * Initial embodied energy: the energy required to initially produce the building. It includes the energy used for the abstraction, the processing and the manufacture of the materials of the building as well as their transportation and assembly on site * Recurring embodied energy: * Recurring embodied energy: the energy needed to refurbish and maintain the building over its lifetime * Demolition energy: * Demolition energy: the energy necessary to demolish and dispose of the building at the end of its life Note: Note: that the cradle-to-grave embodied energy life-cycle does not include the operational energy required to utilise the final product. In other terms it does not account for the heating, cooling, lighting and power of any appliances that allow the building to serve its intended function.

Embodied Energy Constraints * These definitions mentioned are given for energy but are equally valid when considering embodied carbon (dioxide) emissions from production and / or transport ation of materials to and from construction sites. * Constraints in correctly measuring embodied carbon include the sequestration of carbon within building materials such as timber, and the emission (or sequestration) of carbon dioxide (CO²) through chemical reactions during the production of materials such as cement and the lifetime use of materials for example in the carbonation of concrete. Note: Carbon dioxide (CO²) capture and sequestration (CCS) is a set of technologies that can greatly reduce CO² emissions from new buildings and existing coal or gas-fired power plants, and large industrial sources, thus reducing greenhouse gas emissions.

Why Embodied Energy? 40% Building Operations 10% Building Construction and Materials 30% Transportation 20% Industry

Defining Embodied Energy

The Beginning of the Process From the Cradle: In order to reduce the carbon footprint of civil infrastructure it is important that we account for the energy that is embodied or embedded in the construction materials that we use.

Life Cycle of Building Products Raw Material Extraction Occupancy and Demolition Manufacture and Site Construction Process Process

From the Cradle …… Embedded Energy Process The Cradle = Raw Materials Transport Manufacturing Products The Cradle = Raw Materials Transport Manufacturing Products The earth, or grounds raw materials and fossil fuels required to make products

The Carbon Footprint From the Cradle …….. …… To the Factory Gates - Manufacturing To the Site……

Carbon Footprint - Transportation ……… And on to the Construction Site ….And Embedded Carbon

Embodied Energy Amounts

Availability of Materials Transport Costs * For materials not available locally the transportation cost can form a significant part of the materials embodied (embedded) energy life cycle, especially when added to the life cycle.

On-Site Carbon ….And the On-Site Carbon Footprint

Embodied Carbon Embedded Carbon Footprint

Recommendations * Better specification of current materials as steel and concrete are the main construction materials used in UK today. * Energy and carbon content can be reduced by specifying them properly and sourcing them responsibly. * Specification of alternative materials; timber, rammed earth, straw, rubbers, Hemp-Crete etc. * Us of alternative materials appropriate for some design and construction situations in which full advantage can be taken of their low embodied energy content – modular, pre-fab. * Design leaner structures and material optimisation - by minimising the quantity of materials, thus we reduce the energy used to make the building in the first place.

Further Recommendations * Design for deconstruction, reuse and recovery – buildings often have a service life that is far less than that of the materials they are built with. * Building with deconstruction in mind will enhance the reuse of construction materials – effectively increase their life-span and the energy efficiency of the buildings in which they are used. * Design for future use, adaptability and flexibility – designing to make buildings suited to different uses will increase their life-span and reduce the need to use new construction materials. * Continue with the tightening of the Building Regulations’ requirements for operational efficiency

Future Developments * Embodied carbon in particular will gain in relative importance more rapidly with the decoupling of energy generation and carbon emissions. * In the UK, Zero Carbon buildings will become a reality in 2016 for residential homes, and 2019 for other buildings such as commercial and manufacturing. * Embodied carbon will then represent the majority of a project’s whole-life carbon emissions.

Properties

Conventional Eco-friendly Materials

Eco-Friendly Materials……Cont

Reduced Pollution

Performance

Energy Conservation

Recyclable

Summary

Conclusions