Past Architecture

Before the development of modern day HVAC systems, building comfort was achieved through passive means. Climate, not building style or appearance was the major determinant of building form. Comfort was achieved through passive means and features built into the architectural design including building orientation, shading features, use of daylighting, natural ventilation and strategic placement of entrances and windows.

To illustrate this philosophy, consider that the Helenic City of Priene was constructed with the streets running in an east-west orientation so that buildings could take advantage of solar heating. Similarly, Vitruvious emphasized maximum use of the sun in the public baths as shown in the following passage from the chapter in his 10 Books of Architecture that outlines their construction [1]:

“In the first place, the warmest possible situation must be selected; that is, one which faces away from the north and northeast. The rooms for the hot and tepid baths should be lighted from the southwest, or, if the nature of the situation prevents this, at all events from the south, because the set time for bathing is principally from midday to evening.”

Natural lighting was also part of the overall architectural design with features such as atriums, clerestories, and, more recently, the lightshelve, or simply narrow building designs to bring natural lighting into the interior of buildings. As an example, the Roman Pantheon built in 126 AD featured an opening at the top of the dome known as an “Oculus” to bring daylighting to the interior of the building. Although small in comparison to the building, natural light that enters the space provides an illuminance range of 10 to 30 footcandles (100 to 300 Lux) during the daytime. The Galleria Vittorio Emmanuele II, located in Milan, Italy is another example of past architecture designed to provide natural lighting to the covered arcade, but this time from a glassed roof. Finally, the National Building Museum in Washington DC, also shown below, was designed to provide natural lighting to the interior of the offices through clerestory windows located at the top of the atrium, while conventional windows on the building exterior provided natural lighting to the perimeter offices, ensuring complete coverage of the entire space. The architect, Colonel Montgomery C. Meigs stated that the building design ensured no “dark corners”.[2]

Before the development of modern day HVAC systems, building comfort was achieved through passive means. Climate, not building style or appearance was the major determinant of building form. Comfort was achieved through passive means and features built into the architectural design including building orientation, shading features, use of daylighting, natural ventilation and strategic placement of entrances and windows.

To illustrate this philosophy, consider that the Helenic City of Priene was constructed with the streets running in an east-west orientation so that buildings could take advantage of solar heating. Similarly, Vitruvious emphasized maximum use of the sun in the public baths as shown in the following passage from the chapter in his 10 Books of Architecture that outlines their construction [1]:

“In the first place, the warmest possible situation must be selected; that is, one which faces away from the north and northeast. The rooms for the hot and tepid baths should be lighted from the southwest, or, if the nature of the situation prevents this, at all events from the south, because the set time for bathing is principally from midday to evening.”

Natural lighting was also part of the overall architectural design with features such as atriums, clerestories, and, more recently, the lightshelve, or simply narrow building designs to bring natural lighting into the interior of buildings. As an example, the Roman Pantheon built in 126 AD featured an opening at the top of the dome known as an “Oculus” to bring daylighting to the interior of the building. Although small in comparison to the building, natural light that enters the space provides an illuminance range of 10 to 30 footcandles (100 to 300 Lux) during the daytime. The Galleria Vittorio Emmanuele II, located in Milan, Italy is another example of past architecture designed to provide natural lighting to the covered arcade, but this time from a glassed roof. Finally, the National Building Museum in Washington DC, also shown below, was designed to provide natural lighting to the interior of the offices through clerestory windows located at the top of the atrium, while conventional windows on the building exterior provided natural lighting to the perimeter offices, ensuring complete coverage of the entire space. The architect, Colonel Montgomery C. Meigs stated that the building design ensured no “dark corners”.[2]

Design techniques were also applied to keep buildings comfortable in cooling dominated climates ranging from the very mundane such as finishing the building exterior in light colors, to the use of heavy walls to absorb the heat during the day and re-radiate it to the building interior during cool desert nights. Sophisticated natural ventilation techniques were also built into the designs to control indoor temperatures using atriums, thermal stacks and wind towers to catch the prevailing winds (Persia, Africa and Asia).[3]

While not located in a cooling dominated climate, the National Building Museum mentioned above, passively ventilated the offices with fresh air introduced beneath the window sills, flowing through the office space into the atrium and exhausted, via natural stratification, through operable windows on the roof; a design that imitates designs used in Sahara dwellings and is increasingly used today in hybrid ventilated (mixed-mode) designs.[4]

All this changed in the 20th Century with the introduction of HVAC systems and fluorescent lighting which freed the architects from the need to build thermal comfort into their designs. Reliable and economic air conditioning was introduced around the turn of the century that, together with ventilation systems, could bring cool air anywhere in a building. Similarly, the fluorescent lamp became a cheap and reliable artificial light source that could be brought anywhere it was needed. This caused a decoupling of the architecture from the environment as architects gained a freedom to pursue unrestricted designs with no need to make comfort part of the architectural design. The result was buildings that did not coexist with the weather or as Ed Mazria stated in one of his papers [5]:

“architecture has become totally divorced from nature”

What is also interesting to note, is an emergence in standardization of architectural style seen in all regions of the planet regardless of climate. As an example, the ubiquitous high rise office buildings and condominiums with an all around glass curtain wall and a window-to-wall ratio (WWR) of 50% or more are equally present in climates with extreme heat and extreme cold, yet from an energy use and comfort perspective, such a design should only be used in locations with moderate climate. When describing this design trend, Amory Lovins stated that modern buildings have become [6]:

“sealed boxes with inoperable glazings--veritable solar ovens that, with the aid of mechanical cooling, were miracously turned into refrigerators.”

More recently, Joseph Lstiburek made similar remarks in a March 2009 ASHRAE article referring to this trend as:[7]

“the architectural glass and curtain wall disease”

In the past however, architectural style and form were intrinsically tied to the local climate. Thus, the design for that high rise building located in a climate with extreme heat would have been based on a design with minimized window areas plus use of shading elements (overhangs, fins, recessed windows) to control and reduce the solar heat gain, while in regions with extreme cold, the shading elements would be less pronounced in order maximize solar heat gain during the winter months.

[1] De Architectura (Ten Books of Architecture), Chapter 10 Baths, Book 5. Accessed at the Project Gutemberg eBook.

[2] Cox J. E., Miro C. R. 1997. "ASHRAE Executive Committee Tours National Building Museum." ASHRAE Journal. Atlanta, Georgia: ASHRAE. Vol. 39, No. 2, February, p.18.

[3] Energy Conservation Design Resource Handbook, Royal Architectural Institute of Canada. 1979. Ottawa, Ontario: Section 2.1.7.2

[4] Energy Conservation Design Resource Handbook, Royal Architectural Institute of Canada. 1979. Ottawa, Ontario: Section 2.1.7.2

[5] Mazria E. “It’s the Architecture, Stupid!” Solar Today, May/June 2003, pp. 48-51.

[6] Houghton, D. J., et al. 1992. The State of the Art Space Cooling and Air Handling. Boulder, Colorado: E Source.

[7] Lstiburek, J. 2009. “Extreme Heat: Tale of Two Cities” ASHRAE Journal. Atlanta, Georgia: ASHRAE. Vol. 51, No. 3, March, pp. 75-79.