Passive design strategies and innovative materials for Net-Zero Energy Buildings

Buildings account for a substantial share of global final energy use and CO2 emissions, so reducing thermal loads is a prerequisite for delivering net-zero energy buildings (NZEBs) and nearly zero-energy buildings (nZEBs). This PRISMA 2020-guided systematic review synthesises evidence on envelope-first passive strategies and advanced envelope concepts, with a particular focus on (i) orientation and form; (ii) solar control (shading and daylighting); (iii) high-performance insulation and airtightness; and (iv) latent/thermal storage measures such as phase change materials (PCMs). Sixty peer-reviewed journal articles (2012-2023) were selected from 163 records identified in Scopus and Google Scholar, with citation tracking to reduce omission risk. Rather than restating generic passive design principles, the review contributes (a) a transparent coding protocol linking strategies to climate contexts; (b) a climate-strategy matrix that summarises the direction of reported effects and where evidence is most/least consistent; and (c) an evidence-informed limitations map (cost, constructability, maintenance, and validation gaps) to support practical decision-making. Across the reviewed evidence, the magnitude and reliability of performance benefits are strongly climate- and baseline-dependent; therefore, claims are reported with explicit context (climate, building type, baseline, and metric) rather than as universal effect sizes. The paper concludes with a conservative delivery sequence that aligns with the evidence base: prioritise envelope measures that reduce steady-state loads, then manage transient loads (thermal mass/PCM where supported), and finally integrate renewables and controls.