Villa ZE, a modernist and sustainable house in Costa Brava

The villa is designed for a couple and the incidental stay of their friends, and children with partners. In the mild climate of the Costa Blanca it is producing its own energy, year round. The sloping site offers a beautiful ‘vista’ towards the west over the valley of the river Algar. In order to allocate the house close to the garden and at the same time secure its privacy, the main floor is situated at minus 5 m. from street level, on a podium of local natural stone. The house is kept separate from the grounds by a ventilation slot that leaves the space for a glass stair to the entry. The plan is based on a regular grid of 3.60 m. defining the size of the (bed-) rooms. A central patio creates a division between the guest room + studio on the south, and the living, kitchen and main bedroom on the north. The complete volume is integrated by a single roof. A cantilever prevents excessive heat gain in summer, while allowing passive solar energy in wintertime; a process that can also be regulated by the Venetian blinds along the façade. An infinity pool of 12 m. is situated along the terrace, reflecting the sky and the mountains. The spacious terrace is covered by travertino slabs of 1.20 x 0,60 m. Elegant stairs, based on the same measurements, lead to the garden on both sides. All concrete moulds are designed to create a rough texture, while being precise in a vertical grid of 81 mm., so that each step of the staircases is 162 mm. On the roof solar radiant panels provide hot water for taps, shower, bath and floor heating in winter, while PV-panels supply sufficient electricity. Storage tanks, a water deposit and batteries are all located in the basement. The surplus of hot water in summer is diverted to the swimming pool. Apart from its architectural qualities, the house is an important step towards our aim of ‘building with a positive footprint’ (with exception, perhaps, of the application of concrete for the foundations, that has turned out to be locally unavoidable for now; so far, so good). A nondescript site has become a significant location, defining the beautiful view over the valley of the river Algar and the chain of mountains beyond. We have addressed all 7 aspects of a positive footprint: 1. Air: the house has natural ventilation by the ‘patio inglès’ on the eastside. Abundant vegetation –all planted during construction- is reducing the spreading of dust. The garden along the street includes fragrant species like ‘galantes de noche’ (cestrum nocturnum), jasmin, and honeysuckle. 2. All rainwater is collected and kept in a cistern to be used for irrigation. There is reserved space to install a small scale purification plant in the future that will recycle the wastewater; this technology is not yet available on the scale of a single home. 3. Energy: the hot water system and the PV-panels provide more energy than the house is consuming; when the batteries are full, the surplus is fed to the local network. Year round, the energy balance is positive even when the Tesla M3 is regularly charged. 4. Soil: the condition of the grounds was initially poor: a hard mix of clay and gravel, biologically exhausted. By the planting of ca. 70 trees plus flowers beds and bushes, and by creating a system of composting all natural material, the ground has become softer, fertile and more receptive to water when rain falls. 5. Biodiversity: The original (pine-) trees have been kept as well as some indigenous bushes that have settled during construction. But the planting of many different trees and flowers have enhanced biodiversity dramatically. The garden is hospitable to bees a.o. by creating ‘bee-hotels’ using ends of cane from the riverside. 6. Materials: Using simple, non-toxic materials with timber, bamboo, natural stucco and paints. 7. Food: The garden provides a variety of fruits, oil and vegetables. There is no waste since all natural material is composted. The house in an example of modernist architecture, yet with a non-conspicuous but high level of sustainability.