Sustainability Report

Environmental approach

The environmental approach to Walled Courtyard was considered from an early stage. The project’s compact infill setting influenced the arrangement of the plan, with site orientation informing the relationships between rooms, the placement of rooflights, and the courtyard layout.

Within the constrained site, IBLA sought to balance the usable space of the home with the need for adequate light and views. The reinstated boundary walls and absence of external windows shaped an inward-looking plan, organised around courtyards to bring daylight into the house.

Embodied carbon overview

• Material selection was primarily a contextual response to the historic setting, but IBLA notes that environmental performance, embodied carbon, and circularity are consistent considerations within the practice’s design decisions.
• The project uses reclaimed London mixed-stock brick and lime mortar. The bricks were sourced from The Old Slate Yard, with a blend selected to sit close to the adjacent existing garden wall. The mix includes yellow stock bricks alongside some red bricks, reflecting the material character of the surrounding conservation area.
• IBLA notes that brick is supported by an established culture of reuse and recycling, and that it is also the predominant building material within the conservation area. Its robustness, availability, and familiar character informed the decision to use it for the project.

Operational emissions overview

• IBLA reports that the dwelling carbon dioxide emission rate was 6.46 kgCO2/m².
• The house includes high levels of insulation, underfloor heating, and cooling throughout. A Daikin Europe NV air source heat pump was installed, located within the small forecourt at the entrance to the home.
• The glazing was specified from Rationel’s AURAPLUS range. The sliding patio doors and windows use a solid timber-framed, triple-glazed system with an aluminium external face.

Service and maintenance considerations

• The brick walls inside the site were coated with Keim Restauro Lasur, an eco-friendly mineral matt finish that penetrates the brick to protect it while allowing it to breathe. IBLA selected an off-white tone and tested different pigment intensities to balance transparency and paleness, allowing the warmth and texture of the brick to remain visible while unifying the courtyard walls.
• Due to their orientation, the courtyard walls receive limited direct sun. The Keim application also helps to prohibit moss growth on damp brickwork.
• The project also includes a sedum roof. This supports the home’s environmental strategy and restores the impression of a garden when seen from neighbouring buildings, recalling the site’s former use as a walled garden.