Buildings and multi-tenant datacenters (MDCs) have been identified as crucial participants for emergency demand response (EDR) which is the last line of defense to avoid cascading failures during emergency events. One important overlooked fact is that the majority of MDCs are physically located in mixed-use buildings (MUBs) and share the electricity supply with other operations (e.g., office spaces). However, the existing studies on EDR have not considered this fact and EDR for buildings treats MDC operation as “miscellaneous loads”, which nullifies the flexible electricity consumption of a MDC. Furthermore, even when both building offices and MDCs are jointly considered for EDR, tenants will incur cost to shed energy for EDR, which raises serious incentive questions for their participation. To overcome this uncoordinated energy shedding and mis-aligned incentives, we propose a first-of-its-kind incentive mechanism for EDR in MUBs, such that the total incurred loss (e.g., latency performance degradation for tenants of MDC, thermal discomfort for office spaces) is minimized for energy shedding during EDR. We also design a distributed algorithm to implement the incentive mechanism that can optimally (a) control indoor temperature for non-MDC space, (b) perform server provisioning in MDC, and (c) manage on-site electricity generation. Simulation results show that our algorithm has better performance in terms of MUB total cost compared to the current non-coordinated approaches.