English is extremely compact. If you have a certain layout in the English document you want to duplicate, you will have to account for the expansion factor. One good approach is to start with a generous amount of white space in English, which will be correspondingly diminished in the translated version. Other approaches are to reduce margins and font sizes, steal white space from column gutters and graphical elements, or, as a last resort, expand the amount of paper used. Expansion is also a factor in pricing.
Expansion therefore has an effect upon the total cost of the translation.
Most of the statements above are true in relation to Roman languages . These languages tend to be character based rather than word based. Internationalization, in the context of translation, is a jargon word normally used for an approach to creating software that is mindful of multiple linguistic markets. There is a good discussion of this in the context of Unicode on the Unicode site. Please look here .