The construction sector is known for its environmental impact, consuming large quantities of the planet's finite natural resources. In order to change this paradigm, a set of actions is needed linked to the introduction of sustainable practices that seek to reduce waste rates, improve quality in processes and qualify the workforce. In an attempt to identify how sustainable a construction site can be, this paper proposes a sustainability assessment methodology based on good practices adopted by existing environmental certification seals and research into reference cases, using a questionnaire with five themes: waste generation, water consumption, energy consumption, relationship with the environment and pollution prevention. As a case study, an assessment is presented of how the concept of sustainability is being absorbed on the construction sites of fifteen construction companies in Greater Vitória - ES, thus providing an overview of the practices adopted on the respective construction sites.