Sustainability Report
Embodied carbon
The required calculation were made using Design Builder.
The concrete in the foundations, walls (20 cm thick), and slab, combined with the reinforcing bars (rebar) and the large amount of steel (cladding, 3-meter double facade, and roof trusses), account for almost 85% of the project's footprint. As for the carbon captured in the materials, the figure comes from the wood, which retains the CO2 that the trees absorbed during their lifetime. Considering the 195 sqm of 15 mm OSB panels on the roof and the solid wood doors, there are approximately 2 to 2.5 tons of wood in the project.
Operational Emissions / Energy
The calculation estimates an Energy Use Intensity (EUI) of approximately 90 kWh/sqm/year, taking into account the temperate coastal climate of Algarrobo, Chile. The project's envelope—featuring high thermal mass concrete walls, a 3-meter steel double skin facade for passive solar control, glass wool roof insulation, and double-glazed (DVH) PVC windows—drastically reduces heating and cooling energy demands. Multiplying the EUI by the 195 sqm gross floor area yields an annual energy consumption of roughly 17,550 kWh. Applying a standard emission factor for the Chilean electrical grid (approx. 0.28 kg CO2e/kWh), the total estimated operational emissions are 4,914 kg CO2e per year.
Service and maintenance emissions
The service and maintenance emissions are estimated at approximately 120 kg CO2e per year. This extremely low footprint is due to the project's minimal maintenance requirements. Routine maintenance is limited to general cleaning, particularly washing the double steel facade to prevent marine corrosion. The only significant material intervention planned is the reinforcement of the elastic roof membrane every 5 years. By distributing the embodied carbon of the new membrane material over a 5-year cycle, the annualized emissions remain exceptionally low.
The primary structure and cladding rely on concrete and steel, avoiding materials that require frequent painting, varnishing, or chemical treatments. The 3-meter steel double skin not only provides solar control but also acts as a robust shield, protecting the inner envelope from direct weathering and extending its lifespan. Also, the use of PVC for the double-glazed (DVH) windows eliminates the need for the periodic sealing or painting associated with traditional wood or unanodized metal frames.
Afterlife
As only the exteral structure of the house is made of concrete, the floor plan could be easily transformed for another future destination of the project.
The steel framed inner walls, the doors and sanitary artefacts could be taken off and recycled if the project were to be transformed.
Key products in low carbon design
