Usability is one of the quality characteristics having the greatest impact on final user acceptation in a web application context. However, the relationship between usability and software architecture has not been completely identified and characterised. Some work has found some relationships between usability and architecture but not between architectural patterns. This papers main contribution lies in its identification of architecture patterns and how they have influenced usability within the context of web applications. This study is useful for architects and new product designers regarding the early identification of possible problems and/or advantages (at architectural level), using some of them in a web application. Additionally, architects could identify weaknesses in initial designs thereby increasing final user satisfaction. The study could be useful when a web application is being evaluated, since detecting possible usability problems or weaknesses implies that it should be improved. Consequently, some changes would be made to the application, both in its interfaces and at architectural level. In this case, the problem can be related and the most suitable solution be suggested in terms of patterns. The impact of this works architectural pattern has been validated on two Colombian small- and medium-sized enterprises which have exercised some of the proposed patterns and verified their influence on usability properties.