In the United States, 21% of all energy is used in residential buildings (40% of which is for heating and cooling homes). Promising improvements in residential building energy efficiency are underway such as the Building America Program and the Passive House Concept. The ability of improving energy efficiency in buildings is enhanced by building energy modeling tools, which are well advanced and established but lack generality (each building has to be modeled individually) and require high cost, which limits many residential buildings from taking advantage of such powerful tools. This dissertation attempts to develop guidelines based on a per-building-floor-area basis for designing residential buildings that achieve maximum energy efficiency and minimum life cycle cost. Energy and moisture-mass conservation principles were formulated for residential buildings on a per-building-floor-area basis. This includes thermal energy balance, moisture-mass conservation and life cycle cost. The analysis also includes the effects of day-lighting, initial cost estimation and escalation rates. The model was implemented on Excel so it is available for broader audiences and was validated using the standard BESTEST validation procedure for energy models yielding satisfactory results for different scenarios, within a 90% confidence interval. Using the model, parametric optimization studies were conducted in order to study how each variable affects energy and life cycle cost. An efficient whole-building optimization procedure was developed to determine the optimal design based on key design parameters. Whole-building optimization studies were conducted for 12 climate zones using four different criteria: minimum energy consumption, minimum life cycle cost (35 years) using constant energy costs and minimum life cycle cost (35 years) varying escalation rates (-5%, 10%). Conclusions and recommendations were inferred on how to design an optimal house, using each criterion and for all climate zones. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]