HAL were asked to design a grandparent extension for a detached home in Digswell. After discussions with the local planning department, planning permission was approved.

The annex is arranged over two floors to tie in seamlessly with the existing house. The ground floor includes a wheelchair-accessible bathroom and an interconnecting door to the main house, allowing easy access for meals.

The new staircase has been designed to accommodate a chairlift, and the first-floor bedroom features an en-suite wet room, along with another internal door linking back to the main house.

Externally, the walls and roof match the main house, so the extension blends in naturally and barely reads as an addition.

Phase 2 of the project involved adding a basement extension to the rear of the house. The natural drop in ground level worked in the project’s favour, allowing the new basement to open directly onto the rear garden, filling the space with natural light and enhancing its everyday use. Above the extension, a practical roof terrace with contemporary glass balustrading provides additional outdoor space. Access is provided via a staircase positioned within the side conservatory, ensuring seamless integration with the existing layout and avoiding any loss of space within the main house.