Minimalism
Minimalist interior design came about as a direct result of the Minimalist art movement which first surfaced in the 1950s in New York and dominated the art world through the 1950s and 1960s. The art movement came from the overarching movement of the time, Modernism. This is why the terms Modernism and Minimalism are often used almost interchangeably when discussing design. While it is accurate to say that a minimal approach is a modern one, the reverse is not always true.
Minimalist art is self-contained art; external references and emotion are avoided. Interior designers who work with minimalism tend to broadly follow this ideal. The approach to minimalism in interior design is less rigorous than it is in the art world. This is to be expected as a building's interior has to serve a function beyond the aesthetic--it has to be conducive to the act and to the art of living.
There are several distinct objectives within minimalist interior design and the task of the designer is to make these rationales come together as seamlessly as possible. This is no easy task and involves a lot more than knocking down a couple of non-supporting walls and painting everything white.
The Spiritual
The first objective is the spiritual. Minimalist interiors are designed to facilitate a sense of calm and peace. People's surroundings have a huge impact on the way that they feel and consequently act. To this end colors tend to be extremely pale or white so as not to induce an emotional response. The use of whites and pastels on walls also maximizes the reflection of light giving a soft, diffuse illumination that is not harsh or uncomfortable. The minimalist interior designer uses light to define the forms and the spaces where other designers would use materials and finishes.
Open plan designs are favored as this type of architecture promotes a calm, detached feeling. Patterns and textures are generally not used unless they are essential to an object's function. An unfinished brick wall could easily be incorporated into minimalist design as the texture is directly related to its function, but wallpaper with an image of bricks would be about as anti-minimalist as it is possible to be.
The Practical
The second objective is the practical. Multi-purpose objects are important in this regard. The floor that is also a radiator, windows arranged for the gathering of heat as well as light, and even the sofa that converts to a bed all follow the minimalist ideal. This multi-purposing ethos also extends to the use of spaces within the home. A committed minimalist will not be happy until every space serves at least two distinct functions.
Energy Efficiency
Thirty years ago this third objective would have been a subset of the practical. The importance of energy conservation in the light of recent discoveries regarding climate change and potential fuel scarcities means that energy efficiency is now an essential part of minimalist design. In fact it could be argued that it is impossible for a home to be considered an example of minimalist design without a serious attempt at energy conservation. At the very least the house should be insulated and all windows double- or triple-glazed. A purist would argue that the minimalist needs to go beyond these standard measures and look at non-fossil fuel options such as geothermal heating or solar panels.
If a designer meets these three objectives, the design produced would undoubtedly be a minimalist one.
Concluding thought
Of course many will slap a coat of white paint on the walls, rip some carpets up, and put a few openings in walls and call it a minimalist design, but for a design to be truly minimalist a bottom-up approach is needed. The functioning of the home, spiritually, practically, and energy-efficiently, will to a very large extent dictate its appearance. This is true minimalism and it comes from below the surface.