A passive house with resilience

This holiday home belonging to the Heidenreichs can be reached from Buenos Aires in an hour via boat through the narrow twists and turns of the Paraná River. The property is located in the middle of a delta on a small island, which is no issue for these IT entrepreneurs-cum-sailing and boating enthusiasts. However, the idea of building a house on the marshy terrain was not without its problems.

Amphibious construction

Architectural firm MAPA opted for the concept of an amphibious house for this reason. The term is borrowed from the animal kingdom and describes a construction method that allows the building to adapt to rising and falling water levels. Wooden stilts lift Casa Biguá two metres above the ground to protect it from periodic flooding in the Paraná Delta. The building that rises above the floor plate is also a lightweight timber structure, in keeping with the traditional construction methods used on the islands of the delta. The house was built using prefabricated units that could be transported on small boats.

A third element of this project was the passive house construction method. Given the frequent power outages and humid climate in the region, the clients, who had learned about the passive house concept in Chile, were very impressed with the low energy consumption and good air quality of this type of building. They enlisted expert Argentine architect Pedro Reyna, an accredited passive house designer, who worked together with construction manager Joaquín Berdés to successfully adapt the unusual construction project to the high standards of the Passive House Institute.

A house within a house

With a floor area of 400 square metres, the building is especially large. It not only appears airy and light, but it also adapts to the climate thanks to its special construction. The substructure makes the base plate look as if it is floating above the floor. It is covered by a huge mono-pitch roof, which offers protection and shade for the rooms below. The house itself is “slotted” under this roof. The bedrooms, bathrooms and living rooms are spread over a generous 220 square metres. The very spacious 175 square metre deck is used for outdoor living. Sizeable wooden stairs with wide landings lead to the boat dock and into the centre of the island.

Sustainable construction materials

The base structure is made of solid anchico wood – a hardwood that is highly resistant to cycles of wetness and dryness. The structure above the floor plate, including the roof beams that are more than 13 metres long, is made from impregnated glued laminated timber. The elliotis pine wood used for this was harvested from sustainably managed forests.

PVC-U window and door systems from Schüco were selected for the openings. In terms of energy efficiency and sustainability, the Schüco LivIng series impressed the clients with its technical durability and the recyclability of its PVC-U profiles. This is because when the Schüco PVC-U units do reach the end of their useful life after many decades, the materials they are made from can be recycled.

Resilient construction method

The design by MAPA Arquitectos follows a bioclimatic strategy with a lightweight construction method, which provides sun shading and natural ventilation. The layout of the rooms supports interaction with the outside world while minimising energy loss. The main living areas face towards the north, which allows optimal use of daylight. A system of galleries regulates the entry of daylight and creates a fluid transition between inside and outside. Insulation and airtightness comply with passive house principles and provide a level of thermal comfort that the

clients find extremely pleasant. As one of the first passive houses in Argentina, Casa Biguá requires very little energy for heating and cooling. An air-source heat pump feeds into the heating and cooling system. Due to the humid climate in the delta, ambient air conditioning was one of the focal points of the building service concept.

Highly insulated building envelope

An essential feature of the passive house construction method is airtightness of the highly thermally insulated building envelope. Structural insulated panels, also known as SIP panels, were used for these external timber walls, as they retain their insulating properties even in humid conditions and low temperatures. For the openings, Schüco partner El Bulevar Aberturas recommended the Schüco LivIng 82 MD window system as it is suitable for passive houses, as well as an appropriate entrance door from the Schüco LivIng series. The seamless interaction of the various building components is emphasised by the uniform colour scheme, with the PVC-U windows and doors integrated into the black timber outer wall construction using matching foils.

The innovative seven-chamber system from Schüco was able to demonstrate its tested passive house suitability here with excellent insulation properties (Uf values as low as 0.96 W/m²K) and a permanently high sealing effect. The high-quality Schüco LivIng gasket also helps achieve this, ensuring excellent tightness for many years. The strong, anti-corrosion steel profiles in the window and door frames and in the vents and leaves provide long-term stability. Handles and fittings components are sealed against corrosion. Last but not least, the triple glazing achieves excellent U values (Ug of 0.40 W/m²K) with a low-E filter and “Warm Edge” spacers.

“We are over the moon with the quality of our Schüco windows and doors. Even after more than three years, they look as good as new and function perfectly despite the challenging climatic conditions”, comments the client.

For more information, visit www.schüco.com 

Project details
Project: “Casa Biguá“ in the Tigre Delta
Location: 1628 San Fernando/ARG
Client: Erica and Edouardo Heidenreich
Architects: MAPA Arquitectos, Studio Buenos Aires, ARG (now FROM, Montevideo/URY)
Passive house planner: Pedro Reyna, Córdoba/ARG
Site management: Joaquín Berdés, Buenos Aires/ARG
Main contractor: Horacio Battagliero, Battagliero Constructions, Rincón de Milberg/ARG
Schüco fabricators: El Bulevar Aberturas S.A., Tandil/ARG
Certification: Passive House Institute, Darmstadt
Completion date: 2022

Construction data
Primary energy requirement: 87 kWh/m2a
Annual energy requirement for cooling: 15 kWh/m2a
Annual energy requirement for heating: 9 kWh/m2a
U values of the building envelope: opaque building components: 0.28 kWh/m2a, transparent building components: 1.22 kWh/m2a
Air exchange rate: n50 = 0.6/h

Schüco systems used
Windows: Schüco LivIng 82 MD
Entrance door: Schüco LivIng 82 AS
PVC-U profile colour: Black Ulti-Matt, laminated on both sides