Algiers House Renovation | Self-build Low-energy retrofit and extension

Algiers House has been developed through a close and iterative collaboration between the client and Arboreal Architecture, evolving as a carefully considered residential retrofit focused on improving both energy performance and everyday spatial quality for a growing family.

The project reworks the existing dwelling through a series of targeted interventions, balancing extension, adaptation, and environmental upgrading within the constraints of the original structure. The design approach prioritises clarity, daylight, and thermal performance while maintaining a calm and materially restrained architectural language.

Ground Floor Extension

The existing house is extended to the rear to form a larger, more generous ground floor living environment. This new volume is set at a slightly lower level, allowing a subtle shift in spatial hierarchy while strengthening the connection between house and garden.

The extended space integrates the original rear room into an open-plan living and dining area, forming a continuous domestic landscape that opens directly onto the south-facing garden. The layout accommodates varied modes of occupation, including relaxed seating zones, dining areas, and integrated storage elements, all arranged to support flexible family use.

Generous glazing and rooflights introduce controlled daylight deep into the plan, improving natural illumination while carefully managing solar gain and potential overheating. The result is a space that is bright, comfortable, and environmentally responsive throughout the year.

Garden Threshold

A new external deck extends directly from the living space, forming a transitional threshold between interior and landscape. This intermediate zone supports everyday outdoor living - dining, play, rest, and seasonal occupation - while reinforcing the visual and physical continuity between house and garden.

Loft Conversion

At upper level, the loft is reconfigured into a multi-purpose space serving as both home office and guest accommodation. A rear dormer and an additional window on the eastern elevation introduce daylight and framed views across the garden, while extending usable floor area within the roof structure.

The space is designed to remain open and adaptable, balancing a sense of privacy with spatial generosity. It supports focused work while also accommodating occasional guest use, reflecting the evolving patterns of contemporary domestic life.

Location: South-east London, Ladywell, Lewisham, SE13

Property type: Single-family residential dwelling (existing house undergoing retrofit, rear extension, and loft conversion)

Scope: The project involved the low-energy refurbishment and spatial reconfiguration of an existing family home, including a rear ground-floor extension and loft conversion. Works focused on improving thermal performance, daylight access, and spatial flexibility to support a growing family. The ground floor was reconfigured into an open-plan living, dining, and kitchen space with direct connection to the garden via a new extension and external deck. The loft was converted into a multi-purpose office and guest room, incorporating dormer and new window openings to enhance light and usability. The design prioritised energy efficiency, passive daylighting, overheating control, and improved indoor–outdoor relationships while upgrading the existing building fabric for long-term sustainable residential use.

Key Features:

• Low-energy retrofit and extension of an existing family home

• Rear ground-floor extension creating an open-plan living, dining, and kitchen space

• Reconfigured layout to improve flow, daylight, and garden connection

• New external deck forming a transitional indoor–outdoor living threshold

• South-facing garden integration with enhanced visual and physical access

• Loft conversion into a flexible office and guest bedroom space

• New rear dormer and additional window to increase daylight and garden views

• Passive design strategies to improve thermal comfort and reduce overheating risk

• Carefully balanced glazing strategy to optimise daylight and energy performance

• Improved building fabric to enhance overall energy efficiency and reduce heat loss

• Integrated storage and adaptable spatial elements for family living

• Strengthened relationship between existing structure, extension, and landscape

Photos and visuals: Arboreal Architecture