Set in the lush and green countryside near São Paulo, the villa’s windows open wide. On the terrace, the lounge seating, large dining table, and outdoor kitchen mirror the comforts of the interior of the house.

For one active family, architect Marilia Pellegrini designed a home to accommodate the busy vacation schedules of children, friends, and relatives—who stop by, stay, and fill the house with happy bustle. (The villa, located in a residential development in the city of Porto Feliz, São Paulo, serves as a country home for its owners, a couple based in Rio de Janeiro.) In the process, Pellegrini redesigned almost every element of the original house—only its basic structure has survived.

In total, the property features a living room, kitchen, laundry room, swimming pool, and studio for the house staff. (And not to mention, five bedroom suites.) The large living room opens onto a similarly spacious terrace with a large outdoor dining area and an outdoor kitchen and barbecue. Inside, the room is divided into several different spaces: There’s a living space, bar, TV area, as well as intimate and long dining tables that can accommodate up to a dozen guests. The dining area opens onto an adjoining kitchen that can be hidden, partially or completely, behind sliding panels made of wood and tucum fiber. It’s one of the few partitions in this huge space with multiple functions. After all, in this weekend house, residents choose to live surrounded by family and friends.

The materials used and their raw treatment—fossilized wood on one wall, basalt stone for the floors, Corten steel and pequi wood planks as wall cladding—bring the family closer to nature. The fossilized wood was assembled without joints, while the pequi planks show their irregular shapes. (Elsewhere, the basalt stone slabs are assembled with very fine joints, giving the illusion of a single piece of flooring.) Also of note is the staircase, which leads to the upper floor and was constructed out of oak. That same type of material extends to the parquet flooring and woodwork of the bedrooms. The console bar, carved from a thick piece of solid pequi, has an irregular free edge.

Renowned Brazilian designers are well represented inside the ville. Think Claudia Moreira Salles and Jean Gillon, with his 1968 Jangada armchair and ottoman. While the furniture alternates between classic pieces by leading designers and contemporary items, works by artists including Antonio Bandeira, Maria Polo, and José Bechara punctuate the space. The Vanderlei Lopes sculpture in the corridor consists of two “streams” of polished brass, that work to create the look of liquid gold. They serve as a reminder that in this relaxing home, everything and everyone can coexist, be it friends and family, or design elements from the past or present.

Inside a spacious living area.

The kitchen can be seen behind four panels of wood and tucum fiber. On the left, the entrance to the house can be seen. In the foreground, the long dining table can accommodate friends and extended family. Cane chairs and woven rattan hanging lamps complement the fossilized wood wall and the large door made of pequi wood.

The large fossilized wood wall is reminiscent of 1960s houses, another element in the villa’s inspired mix of materials, eras, and styles.

The kitchen can be seen from the dining area, when the sliding panels of wood and tucum fiber are pulled back. The house is open on two sides to light and air.

The entrance sets the tone of the house with raw materials like wood, blown glass, woven fabrics, and basalt stone.

The ambiance of this weekend house is exemplified by the raw simplicity of the irregularly contoured pequi shelf that serves as the bar.

A round table is used for intimate dinners. The outdoor kitchen is visible through the window.

In the hallway, a sculpture by Vanderlei Lopes includes two openings in the wall that appear to let “streams” of polished brass flow onto the basalt tiles.

In this bedroom, simple pieces of wood and woven fibers fit the countryside setting.

A bathroom vanity carved of stone.