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Garden room project · Cosy Garden Rooms

Better than an extension: a multi-functional garden room

A 5.2m × 3m garden room with a 2.35m ceiling, built for a couple who needed an office once their spare room became a nursery, with space for gym kit too.


Published 26 September 2025 · Updated 24 October 2026 · 3 minute read · Written by The Garden Room & Annexe Guide

The new building sits well in the garden
Cosy Garden Rooms  5.2m by 3m office and gym

With a baby on the way, Zac and Jen Clayton needed more space. The room they had been using as a home office was earmarked to become a nursery, but they still needed a dedicated workspace. Like many families, they considered a traditional house extension, but the cost, disruption, and timescales soon made them look for alternatives.

A Cosy Garden Room offered a quicker, more cost-effective solution, and while a smaller building could have worked as an office, the Claytons used the opportunity to go bigger. By designing a purpose-built multi-functional space, they were able to incorporate a home office, exercise equipment, and additional family space into one striking new building.

At a glance

  • Size: 5.2m × 3m, 15.6sqm, with a 2.35m ceiling.
  • Built for: A home office, exercise equipment and family space in one room.
  • Glazing: Sliding doors at the front, French doors on the left and a tall window by the desk.
  • Finishes: Oak composite slats with an Anthracite Grey canopy, cheeks and frames; Hardie® Plank at the back and side.
  • Company: Cosy Garden Rooms, who also made a new base for the client's shed.

Part of our garden gym guide →

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The brief

Tailored around the client’s needs

Measuring 5.2m x 3m, this bespoke garden room offers 15.6sqm of internal space, with a taller-than-standard ceiling height of 2.35m. The extra headroom makes a real difference when using gym equipment, adding to the sense of spaciousness.

A comfortable home office with space for a gym has been created
Office and gym  in one room

Cosy Garden Rooms also went the extra mile in preparing the site. Before the build began, they created a new base to re-site the Claytons’ existing shed, which was in the footprint of the new building. They then installed a concrete slab foundation for the garden room itself-an excellent choice that supports the whole footprint and ensures long-term stability.

Design

Striking contemporary design

The design makes a real impression in the garden. The front and right-hand walls are framed by an Anthracite Grey roof canopy and matching wall cheek detail, with recessed LED downlights adding atmosphere. The clean lines of the canopy have been echoed in a decked veranda that wraps around the building, connecting the two entrances and creating a natural flow between indoors and out.

The multi-function garden room is finished with maintenance free finishes so will maintain its appearance in the long term
Maintenance-free finishes
Exterior grade LED downlights have been fitted into the roof canopy
The canopy  with LED downlights

The Anthracite Grey frames of the doors and windows are offset by vertical composite slatted cladding in a rich natural Oak finish. The colour contrast between the Oak tones and dark grey detailing is both striking and stylish. For the less visible rear and side elevations, Cosy Garden Rooms specified durable Anthracite Grey Hardie® Plank cladding, a practical and economical choice that blends seamlessly with the rest of the palette.

The slatted composite wood cladding in Oak pairs well with the Anthracite Grey finishes
Oak slats  against Anthracite Grey
The Oak slatted cladding works well with the Anthracite Grey finishes
The wrap-around deck
Glazing

Flooded with natural light

Triple-aspect glazing ensures the interior is wonderfully light. On the front elevation, centre-opening sliding doors with full-height sidelights open the space to the garden, while French doors on the left-hand wall create another connection. To the right, a tall window with a top-opening fanlight sits beside the desk area, ideal for both ventilation and working light. Combined with the taller-than-standard, 2.35m ceiling height, the effect is a bright, airy room that feels larger than its footprint suggests.

A large window has been positioned next to the desk so the area is well lit
By the desk  a tall window for light
The design has room for the owners gym equipment
The gym corner
Inside

A stylish, comfortable interior

Inside, the Claytons chose Cosy Garden Rooms’ signature grooved wall panels finished in soft white, paired with a smooth ceiling featuring dimmable LED downlighting. The richly coloured laminate wood floor brings warmth and contrast, creating a comfortable backdrop for the family’s furnishings. The space has been cleverly zoned for working, exercising, and relaxing, making full use of the versatile layout.

Reflecting on their decision, Zac commented: “To be honest, what we’ve ended up with is better than an extension.”

Inside, Cosy Garden Rooms signature grooved panelling is the perfect back drop for the owners furnishings
Inside  soft white grooved panels
Planning something similar?

Learn more about Cosy Garden Rooms

To learn more about this project, you can chat with the Cosy Garden Rooms team on 0115 77 22 715 or by emailing info@cosygardenrooms.co.uk. Their website has plenty more examples of their work if you’d like to explore further. You can also take a look at the other Cosy Garden Rooms projects we’ve featured, where you’ll see how they consistently tailor each building to their clients’ briefs and gardens.

Visit Cosy Garden Rooms More Cosy Garden Rooms projects
More projects like this Garden gyms Gyms with extra ceiling height Multi-use garden gyms 10–20sqm garden rooms
Read the guides What garden rooms cost Permitted development Garden room ceiling height

Published 26 September 2025 · Photographs courtesy of Cosy Garden Rooms.

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