Sustainable Building Industry in Southeast Asia…

ECOWORKS Asia sat down with Robert Himmler, Managing Director EGS-plan (Bangkok) Co. Ltd., an engineering consultancy for energy efficient and sustainable buildings, and talk about on the Development of the Sustainable Building Industry in Southeast Asia.



Robert, you opened EGS-plan Bangkok as a branch office of Germany based EGS-plan International GmbH back in 2015. Can you describe on how the Green Building Industry in Southeast Asia and in Thailand in particular has been developing since then?


When I arrived in 2015 in Thailand there has already been a market for green buildings, but it was mainly limited to pilot projects. Ever since the demand for green buildings has increased rapidly especially in the commercial sector. The demand is mainly driven by green building certificates which are used by real estate developers to improve the quality of their buildings and market them through green building labels. Basically, no premium real estate development in downtown Bangkok can afford not to certify their building according to a green building certification system.

Also, with the challenging climate in Thailand and increasing pollution during the dry season building owner and occupants are demanding buildings with a better thermal comfort and air quality.


When we are talking about Sustainable & Green Buildings, on which criteria a green building is defined?


There is no official definition of sustainability of buildings and therefore, I like to refer to the Brundlandt Report of 1987 which stated that a sustainable development should try to balance environmental, human, and economic aspects. To break down this generic definition of sustainability on a building level, it means that we should build affordable, environmentally friendly buildings which consider human health and well-being.


When meeting with building owners, project stakeholders, architects or designers. What can you suggest on various energy efficiency measures for their buildings or projects?


At EGS-plan in Germany and in Bangkok we are following a holistic approach on buildings:

Firstly, we consult with the architect of a new project to design and orient a building with the goal to reduce the cooling demand.

Which building zones need to be air conditioned and in which zones is it sufficient to implement a passive climate design consisting of shading and sufficient ventilation?

When it comes to air-conditioned zones large, glazed façades with an east and west orientation should be avoided and instead the main orientation should be North and South, because these facades are much easier to protect from the sun by cost efficient overhang shading.

Secondly, we pay close attention to the building envelope and design an insulation concept of the air-conditioned zones which avoids thermal bridges, defines thermal properties of the windows, and avoids air leakage.

Thirdly, we are looking into energy efficient building technologies such as high efficiency chiller, VSD pumps and AHUs as well as daylight-controlled LED. Lately we are trying to establish radiant cooling systems which are already very common in Europe but new in Thailand. From our experience, these systems are superior to any conventional air-conditioning system regarding energy efficiency and comfort.

In the last step we are looking into renewable energy sources to offset part or the whole building energy demand which we consequently reduce during the first two steps.

With a reduced energy demand and increased solar energy generation, the question of energy storages is becoming more imminent especially with the legal and technical limitations of the Thai electric grid where feed in is not always offhandedly possible. Currently we are conducting studies regarding battery, hydrogen, and ice storages in combination with solar energy. The goal is to find cost efficient solutions which increase the solar energy self-use of buildings and release the public grid from the fluctuating solar energy generation.

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As Energy Consultant EGS-plan is doing Energy Audits to help building owners reduce or optimize their energy household of their buildings and facilities. What is your best practice on this?


As all buildings are differently there is no best practice. Therefore, we follow the same holistic approach as we do in new construction projects: we consider the building envelope, building services and renewables:

We first request the expectations and financial possibilities of the building owner. Then we conduct a walk-through audit according to ASHRAE Level 1, to document the condition of the building and make a first identification of low and high investment energy saving measures. During the ASHRAE Level 2 audit we conduct energy and comfort measurements, calculate the required investment costs for the implementation of the improvements as well as the expected energy cost savings and the payback time. In the final step we are supervising the building improvements and measure the energy savings over a certain period.


Green building certification is a valuable way to demonstrate a commitment to sustainable and environmentally responsible construction and operation practices. There are several reputable green building certification programs available worldwide. Which of the programs in your opinion are the most effective for buildings?


Again, there is not one best solution for all building types and owners. Since we can cover all popular certification systems in Thailand, we are doing a thorough consulting with the client regarding expectations and requirements.

Certainly, the most popular green building label in Thailand is the LEED certification system. Since it is one of the oldest systems worldwide, it is well developed and the most famous system. Therefore, there is market demand especially on behalf of large international corporations.

The newest players on the market are WELL and EDGE. WELL entirely focuses on human health and well-being and is therefore often combined with one of the green building certification systems like LEED or TREES. EDGE on the other hand is a simplified system which considers the energy and water demand as well as the embedded CO2 in building materials but leaves out human health and well-being.

Finally, there is the DGNB system. It is certainly the least well know certification system in Thailand, but it has a couple of advantages especially for clients who are more interested in sustainability itself than in marketing since DGNB is the only system which is treating the environmental, human, and economic performance of a building equally. Furthermore, it has a consistent life cycle approach throughout all criteria. Best examples are the full life cycle assessment (LCA) to quantify the environmental impact of the construction materials of a building and 50 years of operation Same with costs: a full life-cycle cost calculation (LCC) has to be calculated for each construction project to guarantee not only environmentally friendly and comfortable buildings but also affordability.

Dr. Robert Himmler is managing director of EGS-plan (Bangkok) Co., Ltd. and is specialized on energy efficient and sustainable buildings and neighborhoods. He graduated in mechanical engineering at University of Stuttgart and did research about an energy efficient office building with radiant cooling systems in the context of his PhD thesis.

As project leader at EGS-plan in Germany he consulted dozens of energy and climate concepts for low-energy buildings, passive houses and plus energy buildings. Highlights of his career were the energy concept for 10 houses of the first passive house neighborhood in Ulm, the building physics price 2003 for the International Solar Centre Berlin, the first LEED Platinum certified building in Austria and the “Prom of the Year Real Estate Award 2013” for the sustainable energy plus factory ELOBAU.

From 2013 to 2015 Dr. Himmler worked as CIM expert and visiting professor at The Joint Graduate School of Energy and Environment (JGSEE) at King Mongkut’s University of Technology Thonburi (KMUTT). In 2015 he founded together with Prof. Dr. Atch Sreshthaputra EGS-plan (Bangkok) Co., Ltd. and is consulting energy efficient and sustainable buildings in Thailand, Southeast Asia and worldwide.

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