We assess the feasibility of a foundation pile heat exchanger based collective district heating and cooling network in a new urban area in Vejle, Denmark. A thermogeological model for the area is developed based on geophysical investigations and borehole information. In tandem with a building energy demand model, the subsurface thermal properties serve as input for a newly developed computational temperature model for collective heating and cooling with energy piles. The purpose of the model is to estimate the long-term performance and the maximum liveable area that the energy piles are able to support. We consider two cases where residential respectively office buildings dominate the building mass. We find that 3-4 floors can be supplied with heating and cooling from energy piles, depending on the use and design of the buildings.