Sustainability Report

The project has several strong embodied-carbon reduction strategies:

• Retention of the existing farmhouse: The original building was restored rather than demolished and replaced. This preserves the embodied carbon already invested in its structure and avoids the carbon emissions associated with demolition, waste processing and construction of an entirely new building.
• Adaptive reuse: Continuing to use the existing structure is one of the project's most significant carbon-reduction measures.
• Reuse of existing clay roof tiles: The original tiles were carefully salvaged and reused on the pitched roof, reducing construction waste and avoiding the manufacture of replacement materials.
• Reuse of on-site volcanic stone: Large pieces of existing piedra de jable, a local volcanic stone, were incorporated into the concrete load-bearing walls of the extension. This reduces the need for newly quarried/imported material and limits transportation impacts.
• Compact extension: The addition was deliberately kept compact and carefully positioned, reducing the amount of new construction and material required.
• Local sourcing: The use of locally available materials and local craftsmanship reduces transportation-related impacts while maintaining continuity with traditional construction practices.
• Minimal construction: The project achieves additional agricultural storage through the semi-basement/covered areas without substantially increasing the building's overall volume.

The project incorporates several passive and active measures intended to reduce operational energy demand:

• Thermal inertia: The extension uses wide, load-bearing masonry walls made from concrete combined with large pieces of local piedra de jable. Their thermal mass helps stabilize interior temperatures and reduces reliance on mechanical heating and cooling.
• Passive environmental design: The project uses orientation, compact siting and thermal mass rather than relying primarily on complex mechanical technologies.
• Solar-control glazing: The large glazed openings use double glazing incorporating SunGuard solar-control glass, helping limit unwanted solar heat gain while retaining daylight and views.
• External awnings: Seasonal external shading reduces direct solar radiation during hotter periods and helps control overheating.
• Generous daylight: Large south-west-facing glazed openings provide daylight and views, potentially reducing the need for artificial lighting during daytime hours.
• Photovoltaic generation: The project incorporates 10 photovoltaic panels, generating renewable electricity on site and reducing dependence on grid electricity.
• Careful orientation and siting: The extension's position responds to the existing building and landscape while supporting passive environmental performance.

Several design decisions can reasonably be identified as supporting lower maintenance and replacement impacts:

• Durable existing structure: Retaining and restoring the original house extends the useful life of an existing building rather than replacing it.
• Traditional materials: Existing clay roof tiles and locally sourced piedra de jable are reused, reducing the need for new material replacement.
• Timber windows: The locally fabricated timber windows maintain a relatively simple, repairable material palette and support local craftsmanship.
• External shading: Awnings reduce solar exposure to the glazing and contribute to thermal control.
• Long-term adaptability: Infrastructure was incorporated beneath the extension so that the current agricultural-storage area can later become habitable space without substantial new construction.