Large Rear Single-Storey Extension in Billericay, Essex

Kirkwood Build designed a rear single-storey extension of over 30 sq m for a detached house in Billericay, Essex, with the build completed in approximately 14 weeks after full planning permission was approved for the first time.

The Project — What the Customers Wanted

The house is a detached property in Billericay with a lovely garden. The customers wanted a roomy new living area across the back of the house, with a combined kitchen and dining space, far more daylight, and a closer link between the house and the garden.

Billericay is a well-liked commuter town, and many of its homes suit the kind of rear extension Billericay families often choose. We work regularly in Billericay and the surrounding Basildon area. You can read more about our work in Billericay.

A Project That Came Through Recommendation

The customers came to us on the recommendation of a previous Kirkwood customer. Much of our work comes that way, and it is always good to hear that someone has recommended us to people they know. We also received a five-star review from the customer when the project was finished.

Project Highlights

A closer look at the key features, finishes and practical improvements that bring the completed space together.

The Design — Gable End, Glazing and Garden Connection

The extension is a single-storey build of over 30 sq m with a gable end. The gable gives the back of the house a clean, modern appearance and adds height and space inside the room.

Large bi-folding doors run across the rear of the extension, fitted with level thresholds. That was a deliberate choice: when the doors are fully open, there is no step between the kitchen and the garden, so the two spaces work as one. The doors open onto a new resin stone patio, which we planned as part of the design from the start, not as an afterthought. Together they create a natural flow from the kitchen and dining area out to the garden.

The Electric-Opening Roof Windows

The roof windows are one of our favourite features on this project. They open electrically to let fresh air into the extension, and they have rain sensors, so they close automatically when it starts to rain.

That matters in a large open-plan kitchen and dining space, where cooking heat and smells build up. The customers can ventilate the room without worrying about leaving a window open if the weather turns. Alongside the bi-folding doors and the rear glazing, the roof windows also bring plenty of daylight into the middle of the room.

The Kitchen and Interior

The kitchen, dining and living areas work as one large room. A kitchen island with quartz worktops forms the focal point, and the same large-format tiles cover the whole floor, with underfloor heating beneath them so a big tiled room stays comfortable all year round.

A media wall and the finishing works complete the space. If you are planning a kitchen extension, Billericay properties can take, this is the kind of layout we design: one room that suits everyday family life and entertaining. Our kitchen extensions page has more examples.

Utility Room and Downstairs WC

We also added a utility room and a downstairs WC. They are practical additions that change how the house works day to day. The utility room offers additional storage and a place to work, separate from the main kitchen, and the WC sits conveniently within the new ground-floor layout.

Planning Permission in Billericay and Basildon Council

Basildon Council is the local authority for Billericay, and it deals with both planning applications and building control locally. Many smaller single-storey rear extensions are covered by permitted development, but this project needed full planning permission. We prepared the drawings, submitted the application to Basildon Council and dealt with the process for the customers.

The decision took approximately 8 weeks, and the application was approved the first time. If you are looking into Basildon planning permission for a larger extension, our planning permission page explains how we help.

Building Regulations

Building regulations are separate from planning permission. Planning looks at whether an extension is acceptable in principle, while building regulations cover the technical requirements of the construction. For this project, Basildon Council building control provided the building control service, including inspections during the build.

Our part was to prepare the building regulations drawings and the structural engineering information. A fair amount of structural steelwork was needed to create the large opening between the existing house and the extension, and that stage took approximately 2.5 weeks. You can read more about our structural engineering service.

The Build and Our Builder Introduction

We did not hand over the drawings and leave the customers to find a builder. We introduced a reliable, vetted builder who carried out the construction, and we supported both the customers and the builder throughout the build. The build took approximately 14 weeks.
It was a large project with a lot going on. Having the design, structural engineering, building regulations and builder organised together meant the customers had support throughout.

Project Costs

The build cost was approximately £184,000 + VAT. The kitchen and tiles were not included in that figure and were additional. The professional fees are shown below.

Item	Cost
Architectural design	£17,995
Structural engineering	£19,995
Building regulations drawings	£16,995
Total professional fees	£54,985
Build cost	Approximately £184,000 + VAT (kitchen and tiles not included)

Every house extension Billericay homeowners commission varies, so costs depend on size and specification. For more examples, see our guide to house extension costs.

Our Complete Service in Billericay

We look after the whole process: the architectural design, planning permission, structural engineering and building regulations drawings, followed by the introduction to a vetted builder and support during the build. Whether you need house extensions Billericay-wide or a single large rear extension, you deal with one team from the first conversation to the finished room.

The starting point is a free Discovery Call, where we talk through what you want and give you an idea of the likely cost. You can also browse our other case studies or read about our single-storey extensions.

Frequently asked questions

Do I need planning permission for a large rear extension in Billericay?

It depends on the size and design. Many smaller single-storey rear extensions are covered by permitted development, but this Billericay project, at over 30 sq m, needed full planning permission. Basildon Council approved it the first time.

Which council covers planning permission in Billericay?

Basildon Council is the local planning authority for Billericay. It deals with planning applications, planning advice and building control for properties across Billericay and the wider Basildon area.

How long does a house extension take from design to completion in Billericay?

On this project, the architectural design took approximately 2 weeks, structural engineering and building regulations approximately 2.5 weeks, planning permission approximately 8 weeks and the build approximately 14 weeks. That is roughly 26 weeks from instruction to completion for a full planning permission project of this size.

Does Kirkwood Build cover Billericay?

Yes. We work on house extension projects in Billericay and across Essex. The starting point is a free Discovery Call, and we can handle everything from the design through to introducing a builder.

What are the benefits of bi-folding doors on a rear extension?

Bi-folding doors with level thresholds connect the inside and outside: when fully open, the kitchen or living space flows straight onto the garden or patio. This project also had large glazed windows alongside the doors, which maximise the natural light and the view of the garden.

Project Details at a Glance

Location: Billericay, Essex
Property: Detached house
Works: Large single-storey rear extension with a gable end, over 30 sq m
Local authority: Basildon Council (planning and building control)
Planning: Full planning permission, approved the first time
Architectural design: Approximately 2 weeks
Structural engineering and building regulations: Approximately 2.5 weeks
Planning process: Approximately 8 weeks
Build: Approximately 14 weeks
Features: Level-threshold bi-folding doors, electric-opening roof windows with rain sensors, kitchen island, quartz worktops, large-format floor tiles, underfloor heating, media wall, utility room, downstairs WC, resin stone patio
Professional fees: £54,985
Build cost: Approximately £184,000 + VAT (kitchen and tiles not included)
Review: Five stars from the customer

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