An innovative building envelope was introduced for daylight permeability in an anidolic manner through the opaque parts of exterior façades and roofs. A prefabricated translucent concrete panel (TCP) with embedded optical fibers (OFs) was coupled with a layer outfitted with compound parabolic concentrators (CPCs). Such TCPs have been predominantly used for aesthetic purposes. Moreover, OFs and CPCs have been used in many industries, particularly for telecommunications and the concentration of solar energy, respectively. The goal of this study was to introduce a novel building-envelope construction solution that can transmit sunlight to the interior of a building. Because of the nature of the traditional building materials blocking the passage of natural light, artificial lighting was constantly required, even during daytime, which consumed a great deal of energy in the form of artificial electrical light. This proposed building envelope is a viable solution to alleviate this inefficiency. Experimental results show the effectiveness and limitations of the proposed solution discussed in this paper.

This work aims to characterize how home energy upgrade projects and programs in the US have evolved over the past decade. It also identifies what changes are needed to drive expansion of the US energy retrofit market in such a way that addresses carbon emissions from buildings, improves resilience and upgrades the housing stock. This review focuses on whole-home energy upgrades, targeting deep energy retrofit savings of >30%. The topics we cover include trends in home electrification, US and European home energy upgrade programs, energy upgrade measure costs, business economics, and health effects. Key changes in project design noted in this review include: (1) the electrification of dwellings with rapidly improving heat pump systems and low-cost solar photovoltaic technology; and (2) a shift away from high-cost building envelope strategies and towards more traditional home performance/weatherization envelope upgrades. Promising program design strategies covered include: (1) end-use electrification programs; (2) novel financing approaches; (3) the use of carbon-based program and project metrics; and (4) “one-stop shop” programs. Based on the existing market barriers, we suggest that the industry should adopt new project performance metrics. Additionally, market drivers are needed to spur widespread energy upgrades in the US housing stock. Costs must be reduced, and projects designed to appeal to homeowners and contractors.