Energy Benefits of Modular Steel Frame Homes

Kalvin Wang
May 13, 2018

Submitted as coursework for PH240, Stanford University, Fall 2017

Introduction

Fig. 1: Building site energy consumption by end use. [3] (Courtesy of the DOE)

Traditionally, homes and buildings are built using wood based systems, typically timber, to provide the initial structure of a construction project. Wood-frame homes rely on skilled carpenters to work out the details of the building like the hip and valleys of the roof and eaves, on the job site. In contrast, steel frame buildings are comprised of metal columns and beams that are precision-punched or laser cut in factories before being transported and assembled on-site. This prefabrication building method not only improves the quality and efficiency of the building phase but has the potential to create tight, energy-efficient building envelopes that decreases a building's energy use over its life cycle.

To provide context on the energy consumption and global greenhouse gas emissions of the building sector, the average energy consumption in the first 6 months of 2017 were 2.15 × 1019 Joules (20,375 trillion BTU) for residential buildings and 1.92 × 1019 Joules (18,196 trillion BTU) for commercial buildings. [1] Globally, the building sector contributes an estimated 30 percent of global greenhouse gas emissions (primarily through the use of fossil fuels during the operational or use phase of a building) and consumes up to 40% of all energy. [2] In particular, the majority of a buildings life-time energy consumption is in heating, ventilation and air cooling (see Fig. 1). [3]

Current Implementations - Steel Frames

Prefabrication steel frame construction are yet to be widely adopted in the U.S. One reason is that the U.S construction industry is highly fragmented with each firm taking only a low industry volume and market share. A Canadian company called BONE Structure however have made significant progress in modular steel frame constructions. BONE Structures utilizes auto and aerospace industry suppliers to fabricate their systems steel components and aims to reduces the number of unique parts while improving functionality. Precise dimensions of steel components allow tight building envelopes to be created and allow minimal transfer of heat and air between the interior and outdoors. This increased insulation raises the building's resistance to heat flow and thus steel framed buildings require less energy for heating and cooling.

© Kalvin Wang. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.

References

[1] "November 2017 Monthly Energy Review," U.S. Energy Information Administration, DOE/EIA-0035(2017/11), November 2017.

[2] "April 2018 Monthly Energy Review," U.S. Energy Information Administration, DOE/EIA-0035(2018/04), April 2018, p. 30.

[3] "2011 Buildings Energy Data Book," US Department of Energy, March 2012.