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We optimize buildings in an integrated design process with the rest of the design team to achieve supreme energy and environmental performance and optimal IAQ. We use advanced computer tools to optimize the building design to achieve the lowest initial costs and the lowest life time costs for the client.

Our knowledge on energy efficiency and green buildings is the result of 34 years of experiences from Europe and Worldwide, including 10 years in SE Asia.

When Integrated Design Optimization is implemented a LEED Gold building typically costs less than 5% extra, and it is a least 5% more valuable. There are no real extra costs for green buildings, only savings.



Why do we do what we do?

Our mission is to influence and implement quantifiable positive change to the design, construction or/and operations of any buildings



We imagine a world where all buildings in the world are energy efficient, environmentally friendly, low carbon, and healthy living conditions, and green buildings are major contributors to solving the climate crisis and ensuring future sustainability for many generations to come. 


We strive to think out of the box. Rooted in a firm understanding of building physics, we formulate and strategize innovative sustainable design solutions.

We use building simulation software to prove our design solutions and influence design optimization decisions in an integrated design process and walk through the implementation process. We measure, analyze and quantify the performance and results of the design solutions. 



For Developers, New Buildings, Tenancy Fit-out or Major Renovations


  1. Solar exposure, shading and heat map analysis for indoor and outdoor spaces

  2. Energy simulations and proposing strategies for optimization

  3. Exploring innovative space conditioning and ventilation systems and strategies

  4. Daylighting and discomfort glare analysis, computer modeling, and proposing optimization solutions

  5. Designing for indoor occupant thermal and visual comfort and well-being

  6. Guidance on sustainable building operation policies

  7. Green material review and recommendation

  8. Review and recommendation on renewable energy potential – e.g. Solar PV

  9. Whole building Life Cycle Analysis calculations and recommending opportunities to reduce embodied carbon

  10. Occupant comfort survey and guidance on improvement strategies

  11. Green building certification guidance and procurement – LEED, GBI, Green Mark, GreenRE, BREEAM, WELL

For Existing Building Owners and Facility Managers

  1. Energy Audit and due diligence study on existing building energy and water systems

  2. REEM (Registered Electrical Energy Manager) Scope and half annual reporting to Energy Commission

  3. Preliminary IAQ (Indoor Air Quality) assessment and review of sufficiency existing outdoor air supply

  4. Data logging and review of existing thermal comfort performance of conditioned spaces

  5. Occupant comfort survey and guidance on improvement strategies

  6. Energy efficiency benchmarking and recommendation on potential energy conservation measures

  7. Assisting to put together short term and long term Energy Reduction Masterplan

  8. Air conditioning system and chiller plant fine-tuning and optimization

  9. Guidance on sustainable building operation policies

  10. Green building certification for existing buildings – LEED Existing Building: Operations & Maintenance, GBI Non-Residential Existing Buildings

  11. Green building certification renewal – GBI RVA

For Townships or Outdoor Spaces

  1. Review of design for walkability and alternative transports

  2. Providing design advise and simulations for outdoor comfort and evaluating risk of wind driven rain

  3. Green building certification for Townships and Masterplan projects – LEED Neighborhood Development, GBI Township, Green Mark Cities

For Organizations and Companies

  1. Sustainability manager virtual head count and outsourcing

  2. Providing advise on Sustainability Vision, Goals and Masterplan

  3. Providing consultancy on strategies towards achieving carbon reduction goals

For Manufacturers, Suppliers and Vendors

  1. Review of material and equipment against latest green certification requirements

  2. Energy simulations to investigate impact of product on buildings


  1. Review of material and equipment against latest green certification requirements

  2. Energy simulations to investigate impact of product on buildings



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Regina Ng

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Peng Peng

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Darren Goh

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Simon Laporte

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Marianne Rehn

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Nataly Ann Haw

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Charles Loo

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Ai Cheng Soong

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Wei Han Wong

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Gregers Reimann

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Josephine Fong

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Sandra Shim

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Annisa Ilias

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Ir. Tan Khim Bok

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Christy Khor

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Cindel Soo

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Sarah Salim


Interested in joining the IEN team? Click here to learn more.

Check out our Health & Mental Wellness program for IEN staff: Click


  • Green Building Index (GBI) Technical Committee   

  • GreenRE Technical Committee

  • Founding contributor to the Green Building Index (GBI) certification tool until its launch in 2009

  • Carbon Assessment of the Built Environment, work in progress in the malaysiaGBC committee

  • Energy Benchmarking for Hospitals, development of proposed benchmarking scheme

  • Development of Building Energy Estimation Tool (BEET), developed by ACEM as Building Energy Intensity Tool (BEIT)

  • Stakeholder engagement for Kuala Lumpur Local Plan 2040 (PTKL 2040), Kuala Lumpur Bicycle Masterplan, and the Energy Efficiency and Conservation Act (EEAC).   

  • Malaysian Green Building Council (malaysiaGBC) member 

  • US Green Building Council (USGBC) member

  • Chairman of EuroCham Green Building committee (formerly EU-Malaysian Chamber of Commerce & Industries, EUMCCI)

  • Frequent speaker / author on topics relating to the green building sector (books/articles/presentation/videos/TV)





  • ASHRAE Technology Award 2024, honourable mention, "SDE1 building"


  • Singapore Institute of Architects, 2 awards for "SDE 1&3" project. Education/Institution category. Additions/Alterations category.


  • Inde Design Awards, Australia, Best of the Best Winner, "School of Design and Environment 1 & 3"


  • WorldGBC Asia Pacific Leadership in Green Building Awards, Leadership in Sustainable Design and Performance, Winner, Paramit Factory

  • ASEAN Energy Awards 2020, Winner of "Zero Energy Building" award. GEO Building (joint winner with NUS SDE4) 

  • malaysiaGBC Leadership in Sustainability Awards, Best New Green Commercial Building, Winner, Suasana PjH, 2C5

  • malaysiaGBC Leadership in Sustainability Awards, Best New Green Factory, Winner, Paramit Factory

  • American Institute of Architects, New York State Design Award Merit (SDE 1 NUS)


  • National Energy Awards, Energy Efficient Designed Building, Winner, KLIA2

  • ASEAN Energy Awards, Energy Efficient Buildings, 1st Runner-Up, KLIA2

  • National Energy Awards, Green Building, Runner-Up, IKEA Cheras

  • ASEAN Energy Awards, Energy Efficient Buildings, 1st Runner-Up, IKEA Cheras

  • ASEAN Energy Awards, Energy Efficient Buildings, 1st Runner-Up, Paramit Factory

  • National Energy Awards, Energy Efficient Designed Building, Runner-Up, Paramit Factory

  • Aga Khan Award for Architecture, Nominated, Paramit Factory

  • A&D Trophy Awards, Professional Architecture | Commercial, Retail and Office, Winner, Paramit Factory

  • Golden Globe Tigers Awards, Green Future Leadership Award, Winner, IEN Consultants


  • FuturArc Green Leadership Award, Commercial Building, Winner, Paramit Factory

  • Europa Awards for Sustainability EUMCCI, Best Sustainability Leader, Nominated, Gregers Reimann


  • RIBA International Prize, Best New Building of the World, Longlisted, Paramit Factory

  • LEAF Award, Commercial Building of the Year, Winner, Paramit Factory


  • ASHRAE Technology Award, Runner-Up, ST Diamond Building


  • ASEAN Energy Award, Winner, ST Diamond Building

  • iNTABest Paper, Winner, IEN Consultants


  • Energy Efficient Buildings, postal stamp series by Post Malaysia, all three building stamps by IEN Consultants


  • ASEAN Energy Award, Winner, Low Energy Office (LEO) Building

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