Risk calculations for energy conservation technologies: the likelihood of realizing design-phase expectations in new construction

Lara Greden, Prasad Vaidya, Chris Baker, David Eijadi, and Tom McDougall, The Weidt Group, USA

Keywords

energy efficiency, risk management, measurement and verification, new construction, design process

Abstract

The risk that a technology will not be implemented or operated as designed is a significant barrier that impedes owners from adopting new energy-conserving building technologies. This results in a feedback loop that encourages decision makers to minimize risk by sticking with the status quo, regardless of the environmental impact. Different technology categories have different levels and types of risks associated with them.

This study assigns levels of risk to technologies by tracing a set of envelope systems, lighting designs, lighting controls, HVAC systems, and HVAC controls in a data set of 38 buildings from the design phase through the initial implementation phase. The likelihood that a technology gets implemented and works as expected is assessed, and risk factors for the various technologies are calculated. Explanations for the levels of risk are supported by interviews with third-party reviewers who serve to assist design teams and owners through the construction phase.

Results show that daylighting technologies, including dimming daylighting controls, have the highest risk of not being implemented—when otherwise chosen at the selection phase—while roof insulation and lighting designs are most likely to be fully and correctly implemented. Analysis comparing the risk to the energy conservation opportunity indicates the need for prioritization and support during the design and construction phases to realize expected levels of energy conservation. Overall, the interviewees said the most common reasons for lower than expected energy savings are that energy conservation measures were cut-out during value engineering or cut-out due to later decisions that a technology was functionally risky. This research supports large scale investments in energy conservation technologies for buildings through rebate programs, code improvements, and design guides created by large owners. It identifies technologies that need a higher degree of building management effort and those that need specific designer, contractor and building operator education.