Gaudí's original plans are dated in March 1883. They were distributed in a long surface of about 12 x 18 meters, with a semi-subterranean basement, ground floor, second floor and attic. The ground floor was laid out around the dining hall with a covered gallery, smoking room and two additional rooms. It was slightly elevated from the ground level to allow greater ventilation and improved lighting for the basement, which was designed for storage. The upper floor, where the family's bedrooms were located, was accessed through a compensated horseshoe-shaped stairway. The stairs continued to the attic, where the service quarters were located.

Casa Vicens was built around two bays that run parallel to the wall that was shared with the convent; wooden beams and Catalan-style vaults were built over the bays, except in the basement, where masonry vaults were used.

The roof is sloped on two sides, with four gables; there is a small path around the edge of the roof, which allows it to be easily maintained. As in all Gaudí's works, the ventilation conducts and chimneys are profusely decorated with the same ceramic material as the facade. They grab the attention of every passerby.

The facade walls are built with visible rubblework, adorned with horizontal rows of ceramics that represent the African marigolds that Gaudí saw on the land before the project was begun. From the second floor up, these rows become vertical and their coating is replaced with alternating green and white tiles. The windows are protected from the sun and curious onlookers with pretty shutters with square geometrical designs.

The home's interior decoration stands out for the large quantities of plaster relieves and paintings of birds and plants of nature, done with great detail. The small smoking room also stands out, being decorated in an Arabic style with a brickwork vault decorated with a sort of stalactites applied with cardboard-stone tiles.