In Pittsburgh, Pennsylvania, IBACOS began the design and development for Lab Home E in response to a builder's need to cost-effectively provide occupant comfort and air quality in a four-story townhome community. Traditional practices located the heating and cooling equipment on the lowest level. This was ineffective, even with multi-zone controls to adequately provide uniform space conditioning. Lab Home E sought to analyze the effects of stratification, a natural phenomenon in tall structures in which rising air currents alter interior air pressures and impact comfort. The results of this program have been used to educate others nationwide on appropriate design solutions for tall residential structures.