Cristina Acha and Miguel Zaballa founded ACHA_ZABALLA_ARQUITECTS office in 2006, which they have been leading since.  Projects range from public spaces and diverse scale of buildings to small-scale temporary interventions in a continual dialogue between strategy and details. Their creations have obtained distinctions in the COAVN, FAD, CSCAE awards, and have been widely published in magazines, media and specialized architecture editorials.

A practice based on the conviction of the relevance of design driven by imagination and empathy to provide useful solutions for everyone. As a studio, the approach is open-ended, driven by optimism and focused in the defence of beauty as a central reason for architecture.

Among its achievements, award-winning projects for intervention in built heritage stand out, such as the Hospedería de Herrera del Duque promoted by the Government of Extremadura or the expansion of the Igorre primary school promoted by the Basque Government, COAVN 2019 award.

Their work covers residential projects of various scales as the 70 public dwelling in Huesca, the 35 social homes in the historic center of Badajoz, or the 15 public dwelling in Sestao currently under construction. As well as others on a smaller scale in which the office tests reformulation through the rescue and reuse of what exists, such as the finalist work for the 2019 FAD awards of the 100.60 apartment in Bilbao.

In 2020 the office is interviewed by the BBC in an analysis of housing in Spain in COVID times.

In 2017, ACHA_ZABALLA_ARQUITECTOS was commissioned by the Basque Government to draft a guide for converting empty premises in ground floors into social homes. Subsequently, they wrote a project as a pilot solution which has been turned under their direction into the first built work of the Loft Study House program in the Santutxu neighborhood in Bilbao.