<p>The electrification of aircraft propulsion has the potential to reduce local gaseous and noise emissions. With initial experiences in electrified, light aircraft and increasing energy storage capacities, the focus shifts to higher power applications. Especially battery-electric aircraft show characteristics which appear favourable for short flight endurance in a commercial operational context. Since many aircraft design studies define top-level aircraft requirements in accordance with existing (conventional) aircraft, the design trade-offs of existing aircraft are also implied. However, battery-electric aircraft differ in major characteristics. To consider these differences, this work presents and analyses design requirements for battery-electric aircraft in different technical and operational environments. Focussing on commuter and regional aircraft, it investigates requirements for battery-electric aerial vehicles and quantifies their effect on aircraft designs. It examines major design parameters and demonstrates their effect on the resulting electric aircraft, its required mission energy, and cost characteristics. The goal is to offer guidance in the requirement definition process for future battery-electric applications. An interdisciplinary framework is established to achieve this goal. It merges classical aircraft conceptualisation methods, such as constraint analysis, aircraft component systems and a mission simulation with novel approaches to dynamic component sizing to illustrate the impact of constraints and input parameters in an operational context.</p>