ÁQuatro is a building and simultaneously the project room of the defunct company União Fabril. Aquatro and an atelier; and an engineering office and a sheet of paper. A4 is a standard format. and an international system. It is 29.7 x 21 cm. It is a blank sheet. It can be vertical. can be read from below. It can be horizontal it can be read in other ways. One A4 is two A5 or four A6. And half an A3 is A4 and a blank sheet. It is an artistic block. The A4 is a horizon of possibilities. There's an idea at ÁQuatro. Many ideas fit in ÁQuatro. Rua Industrial Alfredo Da Silva Baía do Tejo, Barriero, Lisbon, Portugal