Survey of metadata schemas for datadriven smart buildings (Annex 81)

This document is written as part of the A3 Activity of the IEA Annex 811 on Data-Driven Smart Buildings. “This project imagines a future world empowered by access to discoverable, reliable, ubiquitous real-time data from buildings, such that digital solutions can rapidly scale and where energy efficiency knowledge can be widely encapsulated and disseminated within highly accessible software ‘Applications’.” Activity A3 aims to provide the knowledge, standards, protocols, and procedures for low-cost, high-quality data capture, shar-ing, and utilisation in buildings, particularly focusing on ‘Data Information Management’.

In this work, we present a survey of metadata schemas for data-driven buildings. Buildings produce endless streams of sensor, meter, and IoT data. A business-as-usual approach treats each building as a stand-alone entity, replete with bespoke engineering solutions and a mix of standardised and bespoke metadata schemas to describe objects and states within the building. Therefore building an application layer that used these data has to similarly be done with a bespoke solution, because the schema will differ from building to building, from integrator to integrator. This solution is impractical and creates significant inefficiencies that hinder the adoption of digital technologies in buildings, and impede scaling up of existing solutions. Annotating this data so that it can be re-used as effectively and meaningfully as possible, regardless of the building typology, location or fabric, is a task best achieved by a common metadata schema that can be applied across the built environment (standard).

Smart building metadata serves two primary audiences: (1) the person in charge of operational management at a building level, and (2) application developers at a portfolio or sector-wide level. Creating portable appli-cations that use metadata to mask the inherent complexities of each building will, in turn, allow the prolifera-tion of value-adding applications and services. The intended audience of this paper is therefore two-fold: (1) the operational data managers of future data-driven smart buildings and (2) users of such data. This includes building owners, commissioning agents, and system integrators; in short, anyone who is in a decision-making position for choosing or requiring a metadata standard for enabling analytics is part of the audience of this white paper. The aim of this document for that audience is insight and clarity in the overall structure, as well as trade-offs and arguments behind each of the major metadata schemas available for data-driven smart buildings. This includes context to how those metadata schemas are applied in practice.