The phrase "more built up" is typically used to describe an area that has undergone significant development or urbanization. Synonyms for this phrase might include "denser," "more populous," or "more urbanized." Other similar phrases might include "more developed," "more industrialized," or "more modernized." These synonyms all imply an increase in urbanization, population, or infrastructure, and are often used to describe areas that have undergone significant growth in recent years. Whether referring to a small community or a major metropolitan area, these synonyms for "more built up" can help to paint a picture of the changing face of our cities and towns.