Air pollution is a problem affecting indoor environments where the urban population spends between 80 and 90 % of their time. The pollution existing inside is two to five times greater than the outside; this poor air quality can affect people’s health and requires immediate action, which is prompting the development of innovative technologies purifying the interior environment that are able to remedy the effects of many harmful pollutants. Of all technologies, heterogeneous photocatalysis is positioned as one of the technologies with the greatest development in environmental engineering, of application in different sectors because it is a clean and adequate treatment of air with small volume. In recent years the solutions for air purification have been based on TiO2, as a photocatalyst compound, to give rise to this reaction of heterogeneous photocatalysis. But TiO2 has been shown to have certain limitations to be used as a photocatalyst in indoor environments due to its low efficiency with visible light, and regulation problems associated with nanometer particle size and its use in coatings where the TiO2 particle has to remain on the surface. The AMBICOAT project aims to develop coating solutions for the purification of indoor environments. These coatings are based on organometallic compounds (MOFs), as photocatalytic compounds. MOFs present reactivity with visible light, and also preset a high porosity, so they are good candidates for the photodegradation of organic air pollutants in indoor environments. For this purpose, the AMBICOAT project will synthesise photocatalytic MOFs in dry via for the degradation of formaldehyde (some of the most interesting organic components), so that later they can be used in the formulation of photocatalytic coatings for application in the construction sector. These coatings will be applied, later, by application technologies such as spray, roller or printing, to obtain construction materials coated for indoor use, with photocatalytic capacity for the degradation of formaldehyde. During the project a method for measuring formaldehyde will be developed that will be used during all phases of the project, and will serve to measure the reduction of formaldehyde in the final demonstrators.