Single Storey Rear Extension
extension

Single Storey Rear Extension

Chelmsford, Essex

Project Photography

Single Storey Rear Extension — photo 1
Single Storey Rear Extension — photo 2
Single Storey Rear Extension — photo 3
Single Storey Rear Extension — photo 4

Project Details

Client Brief

The clients wanted to improve their home to better suit their growing family, with a new single-storey rear extension and a number of internal alterations. The extension would replace the existing small galley kitchen with a larger open-plan kitchen and dining space, creating a better connection to the garden.

The Property

A family home in Chelmsford, Essex, with an existing rear garage extending beyond the main rear wall of the property. This created an unusual relationship between the existing house, garage and proposed extension.

Design Challenge

The main challenge was designing the extension around the existing garage. As the garage projected beyond the rear of the house, the new extension needed to carefully meet the garage without creating an awkward roof junction or compromising the appearance of the existing property.

Design Solution

A single-storey rear extension was designed to provide a larger kitchen and dining space, with large glazed doors and rooflights bringing natural light deep into the new room and creating a strong connection with the garden. To resolve the junction with the existing garage, a parapet wall was introduced to one side. This neatly conceals the difference in roof pitches between the garage and new extension, creating a clean and simple transition between the two. Internally, the existing galley kitchen was replaced with a generous open-plan kitchen and dining space, providing the family with a much more practical area for everyday living and entertaining.

Key Design Decisions

  • Creating a larger open-plan kitchen and dining space for the growing family.

  • Introducing large areas of glazing to connect the new space with the garden.

  • Using rooflights to maximise natural light within the extension.

  • Introducing a parapet wall to neatly resolve the junction with the existing garage.

  • Improving the overall flow and functionality of the existing home.

Planning

The clients initially wanted to proceed under permitted development rights. However, due to the existing garage extending beyond the rear of the house and the position of the proposed extension alongside it, we identified that the proposals would not qualify as permitted development. We explained the situation to the clients and proceeded with a Householder Planning Application instead. Planning permission was granted on the first application through Chelmsford City Council.

Building Regulations

Building Regulations were undertaken alongside coordination with the structural engineer, ensuring the extension and internal alterations were fully detailed for construction.

The Result

The completed extension has transformed the way the family uses the rear of their home. The former galley kitchen has been replaced with a bright, spacious open-plan kitchen and dining area, with direct views and access towards the garden. The parapet provides a simple and effective solution to the challenging garage junction, allowing the new extension to sit comfortably alongside the existing property. The project was built by Grant Builders, based in Chelmsford.

Inspired by this project?

Get in touch to discuss your own project — we offer a free initial consultation with no obligation.

JMJ Architectural Design Ltd

Residential architectural design services across Essex — specialising in home extensions, loft conversions, new builds, planning applications and building regulations.

© 2026 JMJ Architectural Design Ltd