UNITYUnity is the state of being one or a unit. Unity creates feelings like relaxation and protection or stimulation and awe. It is the cumulative effect seen in any composition.

The 7 key elements through which Unity can be achieved are as follows:

1. Texture

2. Colour

3. Tone

4. Direction

5. Proportion

6. Solid and Void

7. Form and ShapeConsider materials such as stone, glass and steel. They are available in a variety of colours, tones, textures, shapes, proportions, etc. Various compositions of these material properties are possible-the challenge lies in arising at the most pleasing composition. The texture or colour of a single brick or wood panel will differ in effect when it forms a part of the larger composition such as brick wall or a door frame set in a wall.

Unity deals with the arrangement of building materials and building parts (floor, wall, roof, column, beam, etc) to create a good composition. Unity is also obtained by the concept of Trinity (odd numbered elements). One among anyone of these elements can be dominant in terms of size or proportion or functionality of the element, so that the composition is clear and there is balance in composition.Ex: National Assembly building in Dhaka designed by Louis Khan portrays unity. Here in the building, various platonic solids in their transformed forms are used. But the whole building is composed in such a manner that expresses unity.

DUALITY

In Duality, though the elements are similar in all respects, the composition is not clear and creates a no result situation. It occurs when two elements of similar nature are put together and due to similarity it creates conflict, the result of which affects the aesthetics of the composition.

Ex: Gothic Cathedral - Notre Dame de Chartres, France

This should be avoided in any design and if it occurs should be controlled by making one element dominant and other subsidiary elements composed within the same framework. Concept of Trinity Or The other way to avoid duality is to combine two similar elements and make them part of a larger framework. Ex: Romanesque Windows