Rapid urbanization brings with it economic growth as well as energy demand increase. Numerous greenhouse gas emissions are emitted by city activities, given the tiny proportion of renewable energy utilization for electricity generation. This paper investigates the feasibility of utilizing the wave energy converter and offshore wind turbine to support the coastal zero-energy building. With the systematic investigations and analyzes, it takes multi-objectives guaranteeing both economic and environmental improvement. The performance of the instantaneous work is achieved by the simulation study in the simulation software TRNSYS 18 where the building services, storage systems, and renewable energy units are all set up From the aspect of the thermal energy system efficiency, the coefficient of performance is used. The advantageous temperature of seawater is shown by the alternative heat exchanger to the air-cooled cooling tower. By replacing the electric heater with the heat pump, the electricity demand of the heating system is reduced to 26%. Two energy matching criteria, “on-site electrical energy matching” and “on-site electrical energy fraction”, assess the technical performance with a series of wind–wave ratios. The results indicate the combined renewable system highly offsets the power shortage of a single resource. Accordingly, a significant reduction of annual equivalent CO2 emissions is reached. Further, the related techno-economic behaviors are analyzed by relative net present value and relative simple payback period. The evaluations roughly show the feasibility within a 20-year working period. That means the model is a practical solution profitable and environmentally friendly.