Architectural control
Architectural control restrictions are designed to maintain the aesthetic harmony of the community, and thereby also to protect property values.  When a community was first constructed, it likely conveyed a certain look and feel to provide design consistency - which made it easy for the initial developer to market the community to prospective homeowners.  Over time, residents will make modifications to the exteriors of their homes - whether necessary or not - such as changing the paint color or roofing materials, and the addition of landscaping, fences, decks and play areas.  Without an architectural standard, these gradual changes can easily affect the appearance of the community.  Even for condominium owners, they may wish to change the color of their door, or paint their balconies a unique color.  These gradual changes may be perceived as weakening the spirit of common design and neighborhood aesthetic, which may then affect property values.

Appearance is not only limited to upgrades or changes, but also to neglect.  Not everyone takes pride in the appearance of their home and yard.  Imagine how you would feel to live next door to a home where the grass was not cut and the landscaping consisted of dead bushes, paint that is peeling on the house, and an old trailer with a torn tarp is parked in the street.  Architectural control standards help ensure that this situation does not happen with your neighbors, so that your - and their - property values are protected.