Kelcroft E&M Limited
unit A10 Kowloon Bay Hong Kong
+852 2335 9830
home > services > embodied energy

Embodied Energy in Building Construction

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

The materials and components used to construct our buildings required the use of different forms of energy, in the country of orgin, to mine, process, assemble, and manufacture materials and ship to the job site. Since that energy has been used, we call it embodied energy. That energy used is tied to the product or material, from factory door to its grave.

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.

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

Embodied Energy in Structures

The term Embodied Energy is meant to reflect the energy consumed during production stage of materials, for the construction of buildings, in the Hong Kong context, predominantly that includes reinforced concrete, glass, aluminium, and steel.

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

There are few industries remaining in Hong Kong therefore the majority of construction materials and constituent raw materials are generally imported from overseas.

For buildings using cast-in-situ reinforced concrete, its constituents are imported, then either mixed 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 constituents materials for production of cast-in-situ concrete are energy intensive, the raw materials typically produced overseas and shipped to Hong Kong, therefore the resulting carbon emission does not appear as a local emission, so Hong Kong inventory appears lower, and that energy used in production is tied to that material, and embodied energy is the term used to define those emissions.

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

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

Then some materials for example concrete comprise several different elements, which maybe be sourced from different countries. Often one project will have steel and concrete materials from a number of countries, with different production methods and travel distances.

Embodied Energy in Waste

Its often overlooked, after the useful life of a product or material it is sent to landfill, including that embodied 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 (pioneered in Hong Kong);
- waste glass (cullet), a free resource, can be used as a raw material for producing new glass, and used as replacement for silca for producing concrete paving blocks;
- waste gypsum board, a free resource, can be used as a raw material for creating new gypsum board, and can be used as a conditioner added to soil;

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

The EMSD LCA tool provides the calculation software to estimate the embodied energy in Hong Kong building structures, and BEAMPLUS 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 choosen, a bonus point can be earned.

Whilst it is true that 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 the embodied energy can be calculated, it is too late to influence the design.

However, giving the embodied energy data to the designer early, it is hoped that will influence the choice of materials BEFORE commencing the design. After the key decisions are made, repeating the calculation is a futile mathematical exercise.

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

Related Reading

tags: embodied energy, embodied carbon, GHG, carbon emission
#embodiedenergy #embodiedcarbon #carbonemission

date: 30-10-20