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Embodied Energy in Buildings

John Herbert, hong kong energy saving expert, BEAM expert
John Herbert
Director


The materials and components used to construct our buildings require the use of different forms of energy. In the country of origin, energy is used to mine, process, assemble, and manufacture materials or products, they are transported to to Hong Kong and then to job site.

Since that energy has been consumed, it is called embodied energy, you can imagine it as a information tag permanently attached to each material or product, and that embodied energy is tied with the material or product forever, a key point that is often overlooked.

Presently, there is no standard framework used in Hong Kong to assess Embodied Energy or Embodied Carbon, only the EMSD LCCA tool can be used to calculate the embodied energy, and therefore implicitly the embodied carbon.

Embodied Energy an important issue for areas like Hong Kong, that must import 99% of its materials for construction from overseas, for example, Hong Kong does not manufacture steel, it is all imported.

Like it or not, sustainability and energy are two sides of the same coin.

Embodied Energy

The term Embodied Energy is meant to reflect the energy consumed during production of materials or products, for construction that means the materials used to construct our buildings, in the Hong Kong context, that predominantly means the raw materials for reinforced concrete, and finished work such as steel, aluminium, and glass panels.

Other countries often use a much wider range of construction materials during construction, however the general principle is the same.

The production of the concrete, glass and steel require vast quantities of energy, and emit carbon dioxide emissions during those processes.

In Hong Kong there are no steel factories, so all the steel building materials are imported.

For buildings using reinforced concrete, the components are mixed either on site in a batching plant for large projects or mixed in a central concrete plant and transported using concrete trucks to the site.

embodied energy building report

Embodied Carbon and Production

Steel and the materials for making concrete are energy intensive, but are typically produced overseas and shipped to Hong Kong, therefore the resulting carbon emission does not appear as a local emission, but the energy/carbon used is tied to the material, and embodied energy / embodied carbon is the term used to define those emissions.

In a perfect world all the materials would arrive with emodied energy label, totalling up those figures provides the emodied energy figure, but real life is rarely that straightforward.

One element for example steel, can be provided by different factories from different countries, each with a different embodied energy and the data is often difficult to obtain.

Then some materials for example concrete comprise raw materials which could also be sourced from different countries. Often one project will have steel and concrete materials from a number of countries, with different production methods, travel distances and therefore different embodied energy values.

Embodied Energy in Construction Waste

Its often overlooked, after the useful life of a product or material it is often sent to landfill, including that is the embodied carbon and energy used in its production. Therefore, use of post consumer waste including post building waste, is important, where possible materials should be repurposed, some examples:

- waste concrete, a free resource, can be used as a raw material for producing new concrete paving blocks and aggregate
- waste glass (cullet), a free resource, can be used as a raw material for producing new glass, also used as replacement for silca for producing and manufacturing concrete paving blocks;
- waste gypsum board, a free resource, can be used as a raw material for creating new gypsum board (also known as dry board), gypsum can also be used in agriculture as a conditioner added to soil;


There is a fixed quantity of naturally occuring gypsum, once its used you can imagine a future with people digging up landfills to recover the tonnes of buried gypsum.

embodied energy reports



With the expertise to back this up, for example specifying energy, water and waste efficient techniques and equipment in buildings and infrastructure and the specialist analysis techniques to demonstrate the practical environmental performance.

BEAM PLUS EU3 Embodied Energy (v1.2)

The EMSD LCA tool provides the calculation software to estimate the embodied energy in Hong Kong building structures, and BEAM PLUS New Building, credit EU3, encourages embodied energy assessment at the concept stage, giving vital knowledge to designers before key decisions are made.

Under BEAM PLUS EU3, if two or more options are examined, and the option having the lowest embodied energy is chosen, a bonus point is awarded.

Its true, the embodied energy in a structure can be calculated at different stages of the project, it is the same for embodied carbon, even years later after the project is complete.

However, giving the embodied energy data to the designer, BEFORE commencing the design, it is hoped that will encourage and influence the choice of lower embodied energy materials and products.

After the key decisions are made, repeating the embodied energy calculation is a futile mathematical exercise.


For more information about our embodied energy reporting call us today!

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tages: embodied carbon, embodied energy, carbon, EU3, buildings, construction, construction waste,
#embodiedcarbon, #embodiedenergy
date: 13-08-20