The motivation to compare the importance that buyers and sellers give to the diverse characteristics of apartments is its pertinency to grasping the housing market. The objective of this article is to compare the determining factors in the choice and sale of apartments among the potential buyers and sellers. During a sale, the realtors exhibit the dwellings’ positive characteristics, the so-called amenities. The homebuyers must analyse the deal in a rational and well-weighed way, striving to know its characteristics to reduce the information asymmetry. The study focuses on two distinct samples, with the common goal of transacting housing. One of the samples is composed of individuals who are looking for apartments, and the other one of individuals who are selling apartments, both being collected in mainland Portugal. It was verified that there are statistically significant differences between buyers and sellers. Buyers give more importance to certain rooms and the inexistence of negative externalities near their future residence. Sellers emphasise positive externalities and parking spots. This study is expected to contribute to the increase in scientific knowledge on the housing market and to the decrease of the information asymmetry between sellers and buyers. Knowing the importance that buyers and sellers give to the main different factors in the Portuguese real estate market constitutes an advancement of knowledge in this area.