Intervention Architecture completes arched extension in Birmingham

A double-height void left internally as brick face creates a new volume of top light to define a dining zone away from the kitchen in a single open-plan area, while connecting to the entrance hallway and linking the front living spaces with the rear garden.


Project data

The £118,500 refurbishment project to a Birmingham Victorian house includes a two-storey side extension attached to the original gable end, extending the home’s footprint to the side courtyard.

The proportion and positioning of both the oriel window and a double-height slot window creates opportunity for natural ventilation as the void is connected to an upper-level window, allowing air movement through the main spaces and roof outlets.

Percentage of floor area with daylight factor >2% Not supplied
Percentage of floor area with daylight factor >5% Not supplied
On-site energy generation 40%
Design life 50 years



Client’s view

Start on site June 2021
Completion April 2022
Gross internal floor area 101m2
Gross (internal + external) floor area 217m2
Construction cost £118,500
Construction cost per m2 £1,173
Architect Intervention Architecture
Client Private
Structural engineer Complete Design Partnership
Principal designer Intervention Architecture
Main contractor Wow Developments
CAD software used AutoCAD

Environmental performance data

After seeing the beautiful wisteria at the back of the house, this then included adding a rear slot like side extension to enable views to the growing wisteria from the dining space, an internal floor level change which adds volume and natural light to the kitchen-dining space and an inside-outside feel level with the garden.

To the rear of the extension, the elevation features arched metal panels in a white finish to balance the heritage white sash openings with new additions. The arched brick makes reference to the existing Victorian house.

Architect’s view

We worked closely with the client to understand their brief, so we could make the most from their budget and sensitively rework the plan and floor levels to get more from the existing footprint.

Intervention Architecture’s design has changed how we live in the house. As a family, we never spent any time in the kitchen, now it’s the main place we all hang out enjoying precious time together. The void above our kitchen table is the real wow factor. It gives us so much natural light and space, and we love the exposed brickwork of the old exterior wall. It was crucially important that the design respected the heritage and history of the house and I think Anna has really achieved that for us.
Philippa Clarkin, client

A further smaller side return adds to the kitchen width, allowing for a central island, and then carving off the central hallway zone a pantry, cloaks and utility space. To the upper floor, it was important to us that the double-height void is experienced with windows from the bedroom/study space and landing. This is to encourage cross-conversation and views up/down to the kitchen and through to the garden, as well as enabling natural ventilation up and through thermal mass.
Anna Parker, director, Intervention Architecture

A glazed box oriel window will enable wisteria to surround the dining table outlook.