This house seeks to maximize energy efficiency, adapting itself to its program, solar orientation and views of the landscape. The project groups the program carefully in four boxes—kitchen, living and dining room, main bedroom and guest bedrooms—which can be used together or independently. Each box is placed on the ground with precision to find the best views and orientation for its use.
Architecture and Interior Design: OHLAB / Paloma Hernaiz and Jaime Oliver
OHLAB Instagram: @ohlab_architecture
OHLAB Website: www.ohlab.net
OHLAB team: Paloma Hernaiz and Jaime Oliver with Rebeca Lavín, Silvia Morais José Allona, Amalia Stavropoulou
Quantity surveyor: Jorge Ramón
Contractor: Joaquín García Rubio
Structure: Lorenzo Croce
Landscape: Salva Cañís
Kitchen and cañizo works: OHLAB design, Creacuina
Furniture: La Pecera
Photos: José Hevia
Bedrooms face east toward the garden and Bellver Castle; living and dining rooms face southeast toward the sea and garden; kitchen faces south toward a vegetable garden; and in an attic over the living room, a terrace faces toward the view of the sea with a large window that lets in winter sun while protecting from summer sun.
The house is designed to take advantage of natural light and ventilation. It has large windows on the façades facing the sun and smaller windows on the opposite wall to allow cross ventilation in the winter and retain heat in summer. The South-facing openings are recessed to let in sunlight during the winter months but block it during summer, while East and West facing windows have exterior shutters that can be closed in hot weather. The house has been built to meet Passivhaus energy efficiency standards, using a rigorous infographic and thermal study to ensure an optimal heat input with maximum efficiency in winter months and minimum energy use in summer months.
The façade features an exterior insulation system that increases the thickness of insulation up to 15cm and strictly guards all joints to avoid all thermal bridges. Infiltrations through the façade have been reduced to minimum, and heat enclosure has been maximized to overcome pressurization tests in every space. The heat exchanger ensures air renovation wasting no energy, and it is optimized to use heat generated with showers’ steam and cooking for heating. Thanks to this design cooling is not necessary, which is typically an issue in hot days of Mallorca’s summer, while the heating demand is only 11kWh/m2a (a typical house of this characteristics in Mallorca would have a heating demand of 85–100 kWh/m2a) which is solved with perimeter underfloor heating circuit. The energy to heat water for hot water comes from solar thermal installation almost entirely.
The pitched roofs of this house have a system for collecting rainwater, three storage tanks collect water for irrigation and general use while a fourth tank collects clean water for consumption. Two separate tanks—one of 40 m3 and another 8 m3—are arranged by taking advantage of the gaps created between the housing and the slope of the terrain. With this measure, the house is completely autonomous in terms of water. The garden includes a vegetable patch, low maintenance native vegetation and deciduous trees along the south side of the house to protect from summer sun.
The project was designed with a low budget and low maintenance costs in mind. It is a home that promotes environmental and sustainability values, reporting savings and comfort without incurring additional economic effort. The house was completed last September, and monitoring its performance has been key to value the results beyond the happiness and satisfaction of the clients. As of April, they have not turned on their heaters at all, reporting an interior temperature (measured daily– day and night) for the winter between 21ºC to 24ºC, with exterior temperatures between 5º to 15º.