The measures proposed in the sustainable and smart mobility strategy developed by the European commission are crucial for achieving the environmental objectives for 2030. This strategy includes measures specifically aimed at reducing the impact of e-commerce distribution. One widely adopted strategy for mitigating the impact of e-commerce distribution is the establishment of urban consolidation centres (UCCs). While this infrastructure quickly demonstrates its environmental success in urban areas, achieving long-term economic sustainability proves challenging. In this paper, we introduce a methodology aimed at incentivizing parcel carriers to shift towards an economically feasible and environmentally sustainable distribution mode within urban areas by leveraging their own transhipment space. This methodology includes a mathematical program for determining the quantity and locations of parking slots, taking into account the number of parcels and transportation vehicles used. It also utilizes the Continuous Approximation technique to assess the transportation and environmental costs of the proposed solutions. The proposed methodology is implemented for the city of Barcelona, considering three different sizes of parcel carriers: the carrier handling the largest volume of parcels, the carrier handling the lowest volume of parcels, and an intermediate case. The vehicles considered for delivery from the transhipment points include vans, cargo bikes, and trolleys for distribution on foot. The results indicate that a significant reduction in both transport and environmental costs is achieved when using zero-emissions vehicles for delivery from transhipment points for any of the parcel carriers considered.