Low energy buildings are buildings that exhibit energy intensities below 15 ekWh/ft².yr (580 MJ/m².yr) in heating dominated climates. Such an energy intensity is approximately 50% below the typical energy intensity of existing commercial buildings.

This site provides information on design concepts to achieve low energy building designs through application of the Integrated Building Design (IBD) process. The principal focus of the site is on proper design and application of architectural elements, efficient lighting design and efficient HVAC systems to minimize building energy use.
The site is organized in eleven separate pages shown on the left sidebar. The topics that are covered range from a description of the IBD concept to design methods, illustrated through HVAC load calculations and energy simulations. The information presented is a compilation of research papers published by this author over a period of 15 years. The papers are available in pdf format in the “References & Further Reading” page and include three articles specific to IBD published in the ASHRAE Journal between 1996 and 2010 and additional papers presented at conferences.


Readers will find the introduction to the principles of the IBD process simple and straightforward compared to some of the complex language and intricate flowcharts available in the literature. The design approach presented here is based on the principle of load minimization and use of best-in-class technologies. This simple concept was initially described in the December 1996 ASHRAE paper available in the “References & Further Reading” page and follows Albert Einstein’s famous maxim:


Everything should be made as simple as possible, but not simpler.

The “Past Architecture” page links modern low energy buildings to architecture from the antiquity and some of the writings of the Roman Architect Vitruvious to show how today’s low energy buildings are going back to the design principles of the past, given that past architecture relied on daylighting, natural ventilation and other passive designs techniques; elements that are becoming trademarks of low energy buildings.


Building energy use data and metrics are included in the “Building Energy Use Statistics” page. This page references data from Canada, the U.S. and the European Union (EU) to illustrate the significant degree to which the “built-environment” contributes to the use of global energy resources. Energy end-use intensities (EUIs) from the U.S. Commercial Building Energy Consumption Survey (CBECS) and other sources are also included to show the relationship of individual end-uses to total building energy use. This information is used in later pages to prioritize the design techniques that can contribute to the largest reductions in energy use. EUIs are presented in MJ/m².yr  and  ekWh/ft².yr. The CBECS tables available in the 2003 ASHRAE HVAC Applications Handbook (SI Edition) present the data in MJ/m².yr and these values were converted to ekWh/ft².yr. There are also some statistical references that are presented in ekWh/m².yr. The energy intensities are always presented as site energy and no attempt is given to provide equivalent intensities at the source level.


Finally, the remainder of the website describes methods and techniques to achieve low energy designs. Design features are quantified via heating and cooling load calculations and energy simulations. Examples that are presented include illustrations of the energy use impact from optimization of architectural elements, as well as, efficient lighting design and HVAC design optimization.


© Copyright 2013 - 2017 Giuliano Todesco 



  • Are Mainstream Low Energy Designs in the Horizon? The 2015 United Nations Climate Change Conference known as COP 21 that ended on December 12 reached its objective of a global agreement to reduce GHG emissions. It was hailed as a success even though it only becomes legally binding once it is signed by the 55-55 (the 55 nations that account for 55% of total GHG emissions). Critically though, the agreement calls for aggressively tackling GHG reductions immediately in order to reach Net Zero emissions in a couple of decades. Some readers will notice that this is more or less in line with the goals from ASHRAE, the 2030 Challenge and the EPBD from the European Union, although the EPBD target for reaching Net Zero is 2020. The ...
    Posted Feb 15, 2016, 6:40 AM by
  • It’s Not Business as Usual I was reading an article in the Jan. 14 Ottawa Citizen newspaper about the Province of Ontario’s 2014 Annual Energy Conservation report released by the Environmental Commissioner that states that efforts to reduce electricity use and electrical demand are falling short of expectations (1). The article stated that utilities in Ontario have had targets to reduce peak demand and overall use, but almost all electric utilities will miss the peak demand targets and half will miss the overall consumption targets. The official press release said as much and more alarmingly, it stated that public interest in conservation in Ontario seems to be at an all-time low. This is of especial concern in the face of the troubling news ...
    Posted Feb 15, 2016, 6:20 AM by
  • Four Key Design Steps to Achieve Successful Low Energy Designs Efficient building designs with performance levels below 20 ekWh/ft².yr (775 MJ//m².yr) can be attained with relative ease and low energy building designs below 12 ekWh//ft².yr (465 MJ//m².yr) can also be achieved through extreme load minimization coupled with alternative HVAC systems such as CC + DOAS and CC/DV. In North America, these performance levels are not being reached as frequently as the industry would like as evidenced by market studies and energy benchmark data. There are a number of reasons for this ranging from key decisions that are made at the early design stages to the design process itself.   Four key steps are described below that can help overcome the barriers that exist ...
    Posted Feb 2, 2014, 1:23 PM by
Showing posts 1 - 3 of 5. View more »