July 29, 2011 | bfeldman | Sustainability

Energy Efficient Buildings – the Architect’s Role

I recently completed reading the National Renewable Energy Laboratory‘s (NREL) Technical Support Document entitled: Strategies for 50% Energy Savings in Large Office Buildings (pdf). As an architect, it can make for some very technical and dry reading, but this document clearly lays out one strategy for achieving large energy efficiency gains with relatively quick ROI (7-10 years, mostly). And, contrary to what one may think of a document researched and published by the NREL, the strategies used do not include renewable energy. In fact, what I found most intriguing about the approach identified in this document is how incremental and achievable they are for most building types.

The major strategies used by the NREL researchers to achieve 50% energy savings (measured using EnergyPlus modeling over baseline of ASHRAE Standard 90.1-2004) were:

  • building heated and cooled by radiant ceiling systems (versus hydronic VAV system)
  • energy recovery used on systems
  • high-efficiency lighting w/ daylighting and occupancy control
  • air barriers to reduce infiltration
  • high efficiency equipment (boilers,  chillers, air distribution units, and service water heating)
  • reduced window to wall ratio (WWR)

As architects, the items on this list that we have some control over are the air barriers (envelope infiltration), window to wall ratio, and lighting and controls. Window to wall ratio is a very inexpensive way to reduce energy required for heating and cooling of buildings, but gets little attention from architects today. Attention is focused on expensive multiple facade strategies and highly technical automated controls. However, as we learned while performing LEED consulting on a project in Manila, by reducing the amount of facade that was glazed, the overall cooling load on the building was greatly reduced. It’s a good reminder that as much as we like grand expanses of glimmering glass, it comes at a cost and we should be realistic and conscious of these costs. The low-tech and straightforward should be our new baseline, as they are highly reliable, low maintenance, and typically quick ROI – a trifecta for our clients.

Finally, this document and it’s findings reinforced to me that architects to have a critical role to play in the efficiency of our buildings. We cannot just relegate this to our engineers. Ultimately, to best capitalize on building efficiency, the process begins with the building orientation, floor to facade area ratios, window to wall ratios, envelope, daylighting, etc. Furthermore, these items should be linked to the proper heating / cooling / and lighting systems to further maximize efficiency gains. This implies more collaboration during early design than has been typical between architects and MEP engineers traditionally.

I will delve into at least one method to achieve this collaboration with a future post on Integrated Project Design and BIM.

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