Bespoke build garden room in Barnes , London

Andrew Hargreaves
Mar 11
5 min read

Updated: Mar 16

A Specialist Build Using Western Red Cedar and SIPs Panels.

Garden rooms have become one of the most sought-after home improvements in London, offering homeowners a flexible space for work, relaxation, or hobbies without the disruption of a full extension. However, not all garden rooms are the same. Many are mass-produced or built to a standard template, which can limit design flexibility and quality.

Recently, our team completed a bespoke garden room installation in Barnes, London, built using structural insulated panels (SIPs) and finished externally with Western red cedar cladding. This project was a great example of how specialist craftsmanship and tailored construction can create a truly unique outdoor space that perfectly fits a client’s vision.

In this blog, we’ll walk through the project from concept to completion and explain why the client chose a specialist builder rather than a standard garden room company.

The Client’s Vision

The homeowners in Barnes approached us with a clear idea of what they wanted from their new garden room. They had already explored several well-known garden room companies but quickly realised that many offered only standardised designs with limited customisation options.

Their project required a number of specific details that were not available with off-the-shelf garden room packages. These included:

A highly insulated structure suitable for year-round use
Premium natural materials, particularly Western red cedar
A precisely positioned structure to maximise light while maintaining privacy
Specific internal detailing and finishes
Structural performance equivalent to a small extension

Because of these requirements, they were looking for a specialist builder capable of designing and constructing a bespoke structure, rather than installing a pre-manufactured garden room.

Why SIPs Panels Were Chosen

One of the key design decisions for this project was the use of SIPs (Structural Insulated Panels) as the main structural system.

SIPs panels are widely used in modern construction because they combine excellent structural strength with very high thermal performance. Each panel consists of an insulating foam core sandwiched between two structural boards, creating a rigid, energy-efficient building component.

For this Barnes garden room, SIPs panels offered several important advantages:

Exceptional Insulation

The clients wanted a space that could be used comfortably throughout the year, including during colder winter months. SIPs panels provide significantly better insulation than traditional timber framing, helping maintain a stable internal temperature.

Faster Construction

Because SIPs panels are prefabricated to precise dimensions, the main structure can be assembled quickly on site. This reduces disruption for the homeowner and ensures accurate construction.

Structural Strength

SIPs panels create a very strong and rigid structure, which allowed us to incorporate large glazed openings without compromising stability.

Airtightness and Efficiency

The tight joints between panels improve airtightness, reducing heat loss and improving overall energy efficiency.

These benefits made SIPs the perfect structural system for a high-performance garden room designed for daily use.

Premium Western Red Cedar Cladding

To achieve the aesthetic the client wanted, the exterior of the building was clad in Western red cedar, one of the most sought-after timber cladding materials for outdoor structures.

Western red cedar is known for its natural beauty, durability, and resistance to decay. Its rich tones and distinctive grain patterns create a warm, contemporary appearance that works particularly well in garden settings.

For this project, the cedar cladding was installed with careful attention to detail to ensure a clean and modern finish. Over time, Western red cedar naturally weathers to a soft silver-grey colour, which many homeowners find highly attractive.

The benefits of using cedar for this garden room included:

Natural resistance to moisture and insects
Excellent dimensional stability
Minimal maintenance requirements
A premium architectural finish

The cedar cladding helped the building blend seamlessly with the surrounding garden while still making a striking design statement.

Preparing the Site in Barnes

Before construction began, careful preparation of the site was required. Gardens in London often present unique challenges, such as limited access, neighbouring properties, and tight working spaces.

In Barnes, we carried out detailed planning to ensure that materials could be delivered efficiently and that construction could proceed with minimal disruption to the surrounding area.

The groundwork stage involved:

Setting out the exact position of the structure
Preparing the foundation system
Ensuring proper drainage and ground stability
Establishing accurate levels for the building

Solid foundations are critical for any garden room, particularly when using SIPs panels, as the panels require a perfectly level base to ensure proper alignment during installation.

Constructing the SIPs Structure

Once the foundations were complete, the SIPs panels were delivered to site and the structural assembly began.

One of the advantages of SIPs construction is the speed at which the building envelope can be erected. Within a short period, the walls and roof panels were installed, forming the insulated shell of the garden room.

During this stage we focused on:

Ensuring airtight panel joints
Accurate alignment of structural components
Integrating openings for doors and glazing
Preparing the roof structure for finishing materials

Because the panels arrive pre-cut to exact measurements, the installation process is both efficient and precise, resulting in a highly accurate finished structure.

Bespoke Detailing and Custom Features

One of the reasons the client chose a specialist builder was the ability to incorporate custom design details that standard garden room companies often cannot provide.

Throughout the project we worked closely with the homeowner to ensure every element matched their expectations.

Some of the bespoke aspects included:

Custom internal layout and finishes
Precise placement of windows to capture natural light
High-quality materials throughout the build
Tailored structural detailing to suit the garden environment

Unlike mass-produced garden rooms, this structure was designed and built specifically for the site and the client’s requirements.

This level of flexibility is often the key difference between specialist garden room builders and standard package providers.

A Garden Room Designed for Year-Round Use

The finished garden room in Barnes is far more than a simple outdoor building. Thanks to the SIPs construction and high-quality materials, it performs more like a small extension to the home.

Key features of the finished structure include:

Excellent thermal insulation
Comfortable year-round internal temperatures
Durable natural exterior materials
A contemporary architectural appearance
A flexible interior space suitable for multiple uses

The homeowners now have a dedicated space that can function as a home office, creative studio, or quiet retreat, all within the privacy of their own garden.

The Value of Choosing a Specialist Builder

This project demonstrates why many homeowners choose a specialist builder rather than a standard garden room company.

While off-the-shelf garden rooms can work well for simple installations, they often come with limitations in design, materials, and structural options.

By working with a specialist builder, clients benefit from:

Greater design flexibility
Higher-quality construction methods
Premium materials such as SIPs and cedar
Tailored solutions for challenging sites
A truly bespoke final result

For this Barnes project, those advantages were essential to achieving the client’s vision.

Final Thoughts

The completed garden room in Barnes, London, is a perfect example of how thoughtful design, high-performance materials, and skilled craftsmanship can transform a garden space.

By combining SIPs panel construction with Western red cedar cladding, we created a building that is not only visually striking but also highly energy-efficient and durable.

Most importantly, the project delivered exactly what the client wanted: a bespoke garden room built by specialists, designed around their specific requirements rather than limited by standard templates.

As demand for garden rooms continues to grow across London, projects like this highlight the value of choosing experienced builders who can deliver truly custom solutions.

If you’re considering a bespoke garden room in London or the surrounding areas, working with a specialist builder can make all the difference in achieving a space that perfectly suits your home, garden, and lifestyle.

If you would like to discuss your garden room project.