The rapid developments in molecular sciences like nanotechnology and self-organizing molecular systems generate a wealth of new materials and functions. In comparison to electronics the application in architecture remains somewhat underexposed. New functionalities in optics, responsive mechanics, sensing and adjustable permeation for gases and water might add to new opportunities in providing for personal comfort and energy management in houses and professional buildings. With a number of examples we demonstrate how complex but well-controlled molecular architectures provide functionalities worthwhile of being integrated in architectural designs. Optical coatings are capable of switching colors or reflectivity, creating possibilities for design but also for the control of thermal transmission through windows. They respond to temperature, light intensity, or both. Selectively-reflective thin polymer layers or paint pigments can be designed to switch between infrared and visible regions of the solar spectrum. Coatings can be designed to change their topology and thereby their appearance, of interest for in-house light management, or just for aesthetic appeal. Plastic materials can be imbued with the property of autonomous sun tracking and provided morphing behavior upon contact with moisture or exposure to light. Many of these materials need further developments to meet the requirements for building integration with respect to robustness, lifetime, and the like, which will only be accomplished after demonstration of interest from the architectural world.