Connecting, Nurturing, Creating for Sustainable Environment

Energy Efficient Retrofits Guide: Content



Overview of this Guide

Section 1 - Introduction

  • Section 1.1 Introduction to the Guide
  • Section 1.2 Categorization of building types for the purposes of this Guide and Retrofit Calculator
  • Section 1.3 Structure of this Guide

Section 2 - Energy Saving Technologies and Initiatives

  • Section 2.1 Methodology: Modelling Costs & Savings of Key Technologies and Initiatives
  • Section 2.2 Findings Regarding the 4 Building Types
  • Section 2.3 A Visual Representation of Energy and Carbon Savings [Marginal Abatement Cost Curves]
  • Section 2.4 Energy Saving Technologies and Initiatives: A Directory
    How much can you save? When are they most impactful?
    • Façade
      • 2.4.1 High Performance Glazing
      • 2.4.2 Solar Control Window Films
    • Lighting
      • 2.4.3 Light-emitting Diode (LED) Lighting in Landlord Areas
      • 2.4.4 Reduced Illuminance to 300lux
      • 2.4.5 Daylight and Occupancy Sensors
    • HVAC - Chiller Plants
      • 2.4.6 Seasonal Chilled Water Temperature Reset
      • 2.4.7 Variable Speed Drive (VSD) Chillers
      • 2.4.8 Oil-free Magnetic Bearing Chillers
      • 2.4.9 Variable Speed Drives (VSD) on Chilled Water Pumps
    • HVAC - Air-side
      • 2.4.10 Demand-controlled Ventilation (DCV)
      • 2.4.11 Electronically Commutated (EC) Plug Fans
      • 2.4.12 Direct Current (DC) Fan Coil Units (FCUs)
      • 2.4.13 Variable Refrigerant Flow (VRF)
      • 2.4.14 Intelligent Building Control Systems
      • 2.4.15 High Volume Low Speed (HVLS) Fans
      • 2.4.16 Carbon Monoxide Sensor Controls for Carparks
    • Lifts
      • 2.4.17 Variable Voltage Variable Frequency (VVVF) Lift Drives
      • 2.4.18 Regenerative Braking Lifts
    • Hot Water Supply & Renewable Energy
    • Other Non-modelled Initiatives
      • 2.4.23 Retro-commissioning (RCx)
      • 2.4.24 High Efficiency Gas Technologies
      • 2.4.25 Radiant Chilled Ceiling Systems (Chilled Beams)
      • 2.4.26 Resizing Pumps
      • 2.4.27 Task Lighting
      • 2.4.28 District Cooling System (DCS)

Section 3 - Retrofit Calculator Manual 

Section 4 - Background

  • Section 4.1 Climate Change - Trends and Impacts 
  • Section 4.2 Global Climate Change Policy
  • Section 4.3 China and Hong Kong’s Overarching Climate Policies
  • Section 4.4 Buildings Energy Efficiency: Why So Critical to Climate Change?
  • Section 4.5 Existing Commercial Buildings: Why So Important?
  • Section 4.6 Usage of Different Fuel Types in Commercial Buildings
  • Section 4.7 Policy Framework for Buildings Energy Efficiency
  • Section 4.8 Roadmap to Improving Existing Commercial Buildings
  • Section 4.9 Addressing Common Barriers to Retrofitting Buildings


  • Appendix A Assumptions used in the 22 modelled Energy Saving Initiatives
  • Appendix B Technical Details of Buildings Modelled for Sample Studies
  • Appendix C Model Output Results for Sample Studies
  • Appendix D Methodology of the Retrofit Calculator

Useful Links




"Energy is an essential part of daily life but enhancing the energy efficiency of Hong Kong’s buildings is important for a number of reasons. It helps reduce carbon emissions and as a result tackle climate change, one of the most urgent and harmful global challenges of our time. It also reduces air pollution, important for the liveability of Hong Kong. Eliminating unnecessary energy usage in our buildings also avoids wasting resources and makes good business sense.

We are pleased that the Government has stated the importance of energy saving not only in its Climate Action Plan 2025 but also in its Energy Saving Plan 2015. Government has set targets for 2025, of reducing the energy intensity of the economy by 40%, and has committed to taking a lead in doing so.

The business community also has an important role to play in enhancing the energy efficiency of our buildings.  There are many mature technologies that can be used to reduce the energy usage of our building stock, and often these can be introduced with net savings.  These are win-win solutions and the earlier that we start to use them, the sooner Hong Kong reduces its overall carbon emissions to the atmosphere.

I am pleased that BEC is launching this Retrofit Guide and Calculator, which are practical enabling tools to support businesses in their transition to well-managed energy efficient buildings. Our approach recognizes that businesses need information to make good decisions as to energy saving solutions that offer the biggest reductions for the expenditure involved. We hope these Tools will offer business at least some of the information they need in their pathway to highly energy efficient buildings."

Mr Richard Lancaster

"As the Chairman of BEC’s Energy Advisory Group, which has steered this project along the way, I am pleased to promote this Guide to Energy Efficient Retrofits in Office and Hotel Buildings to all those looking for cost-effective energy saving solutions.

The Hong Kong Government published the Energy Saving Plan for Hong Kong’s Built Environment in 2015 aiming to reduce the energy intensity of Hong Kong’s economy by 40% by 2025. More recently, it published Hong Kong’s Climate Action Plan 2030+ with targets to reduce carbon intensity by 65-70% by 2030. The Action Plan highlights energy efficiency of buildings as the most important step after improving the fuel mix.

But what are the most cost-effective energy saving solutions? How does a buildings manager or a sustainability manager build the business case for capital spend? That’s the purpose of this Guide. It aims to arm sustainability officers and buildings managers with the information needed to act and invest – at least part of the “proof of performance” that they look for.

The Guide focuses on energy efficient technologies and strategies for commercial buildings, which are responsible for 60% of buildings electricity consumption. The Buildings Energy Code already provides a framework for new buildings, hence our focus on existing buildings.

It shows the cost savings, energy savings and return on investment for the most important energy saving technologies and initiatives in simple “marginal abatement cost curves”, calculated using robust simulations. The Retrofit Calculator that accompanies the Guide is a simple, easy-to-use excel spreadsheet that enables the calculation of approximate energy and cost savings for specific buildings."

Mr Tony Small
Chairman of Energy Advisory Group

"For Konrad-Adenauer-Stiftung, energy efficiency is vital in reducing the risk of severe climate change. We are firmly committed to the goal of keeping the global temperature rise under the 2°C maximum set out in the Paris Agreement. We recognize the important contribution of all cities and countries in the transformation that is needed to achieve this.

The largest source of greenhouse gas emissions worldwide is related to energy, generation of electricity from fossil fuels or burning fossil fuels for heat or mobility. In Hong Kong, approximately 70% of our greenhouse gas emissions come from electricity generation. 90% of this electricity is used in buildings. Hence the importance of a focus on reducing electricity usage in buildings.

However, energy efficiency is not only important for mitigating climate change. It is also important for energy security and stability around the world. Excessive demand for energy will be a source of conflict and instability.

The evidence, reflected in this Guide, shows that in Hong Kong like elsewhere there is considerable scope for businesses to work more ambitiously to reduce their energy usage. This can be done in a way that works for business and the economy: costs can be reduced and innovation and new technologies supported. We see enormous potential for improvement for the benefit of Hong Kong in terms of efficiency and in generating the expertise to make the most of new business opportunities for example along the Belt & Road.

To make rapid and meaningful change, collaboration by businesses and experts to share experience and knowledge is so important. And this project is in our eyes a good example of how businesses through BEC have come together to develop useful and robust guidance.

I hope that the study underlying this Guide and the Retrofit Calculators published will contribute to Hong Kong’s green transformation. The city should strengthen its efforts to become a pilot for other metropolitan areas in Asia in sustainable development and our foundation will be a partner on this path."

Dr Peter Hefele
Regional Director of Energy Security and Climate Change Asia-Pacific


Overview of this Guide

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