Using solar energy stored in the ground to preheat incoming fresh ventilation air with ground loops is a renewable energy system which is becoming more frequently used in new residential developments. The purpose of this research was to examine the effect of ground loop to foundation wall clearance on building heat loss. Additionally, the thermal properties of the soil were examined to determine their impact on the ground loop’s effect on heat loss. A simulation based research approach was conducted using HEAT3, which is a three-dimensional transient heat transfer software. This study found that ground loop clearance had a larger impact on building heat loss for areas with low thermal conductivity soils than for areas with high thermal conductivity soils. On average, ground loop clearances of 10cm, 50cm, 100cm, and 200cm resulted in increased building heat losses of 20%-83%, 19%-55%, 16%-35%, and 12%-15% respectively.