Garden Annexes 45sqm to 55sqm in Size
Updated: 1 December 2025
On this page, we are featuring garden annexe projects between 45 and 55 square metres in size. This size of annexe footprint offers a lot of flexibility, allowing for a spacious and functional living environment. While some projects maintain an open-plan layout for easy, accessible living, with zones for eating, sleeping, and relaxing defined by furniture arrangement, others use partition walls to create more defined rooms. In addition to a separate bedroom, annexes of this size can also accommodate features like an entrance hall, utility room, or dedicated storage spaces, enhancing both comfort and practicality.
See Which Annexe Specialists Work in Your Area
If you're interested in slightly smaller options, be sure to check out our page on garden annexes between 35 and 45 square metres, where you'll find examples that offer similar flexibility within a more compact footprint.
Each project showcased here has been tailored to meet the owner’s specific needs and the available space in their garden. Whether designed for guest accommodation with en-suite facilities or as a self-contained living space for a relative seeking independent living, these garden annexes offer a wide range of possibilities.
These annexes have been designed to comply with either Full Planning Permission and Building Control regulations for permanent residences or have been classified as mobile homes under the Caravan Act. In the latter case, a Lawful Development Certificate confirms their legal status, ensuring they meet all necessary regulations for use as independent living spaces.
We hope these projects inspire you and show the potential for creating flexible, well-defined living environments within this footprint range. The projects are listed by size, from smallest to largest. If you're interested in exploring additional options, feel free to check out our case studies on one-bedroom, two-bedroom, and open-plan studio annexes.
This 45 sqm (9m x 5m) pitched roof living annexe by Swift Unlimited offers a bespoke, modern home designed for long-term comfort. The open-plan living space features an L-shaped kitchen, dining, and seating areas, filled with natural light through French doors and a skylight. The vaulted ceiling enhances the spacious feel, while the double bedroom includes a garden-facing window and an en-suite shower room. Swift Unlimited managed the entire project, from design to final utility connections, completing the build in just five weeks. Durable materials like Western Red Cedar and white render ensure a low-maintenance exterior.
This 45 sqm one-bedroom garden annexe by A Room in the Garden features an exterior design that complements the stone and timber finishes of the main house. Western Red Cedar cladding on one side adds durability and clean lines, while stone cladding on the other reflects the character of the primary residence. Inside, the annexe includes a welcoming entrance hall, an L-shaped kitchen, a spacious living area with bi-fold doors, and a double bedroom with fitted wardrobes and an en-suite bathroom. A Room in the Garden managed the entire project, ensuring a seamless blend of style and functionality.
This 46.2 sqm accessible open-plan garden annexe, designed by A Room in the Garden, provides independent living with unique character. Measuring 6.6m by 7m, the one-bedroom annexe features an open-plan layout, with only one wall separating the kitchen from the fully accessible shower room. A large stained glass window, a nod to the client’s previous home, adds a personal touch. The shower room includes an extra-large cubicle with a bench seat for accessibility. The exterior is clad in low-maintenance black corrugated metal, complemented by black uPVC doors and windows. A Room in the Garden handled all aspects of the build, including utility connections.
This 47 sqm L-shaped one-bedroom garden annexe, designed and built by Executive Garden Rooms, offers a modern, self-contained living space ideal for an elderly parent. The annexe includes a double bedroom, a shower room, a storage cupboard, and a multifunctional living area that maximises garden views. The light-filled living room includes French doors, while the kitchen is customised with high-gloss units and integrated appliances.
This 47 sqm L-shaped garden annexe by Executive Garden Rooms was designed as a self-contained home for an elderly relative, offering both independence and proximity to family. The thoughtfully tailored layout includes a spacious open-plan kitchen and living area, a double bedroom, and a shower room. Key features include a U-shaped kitchen with a breakfast bar, pressurised water system for consistent shower pressure, and a sedum roof that enhances insulation and biodiversity. Clad in a mix of fire-resistant Cedral boards and UV-protected Western Red Cedar, the annexe blends safety with style. Executive Garden Rooms managed the project from design through to completion, ensuring a fully commissioned, move-in-ready home.
This 48.83 sqm one-bedroom garden annexe, designed by Swift Unlimited, offers a bespoke living solution for a client downsizing from a large house in Margate. The annexe features a well-equipped L-shaped kitchen, a spacious living room with roof lights, and a separate bedroom with an en-suite bathroom. Thoughtful design choices, such as internal pocket doors, maximise space and improve movement throughout the home. Swift Unlimited managed the entire process, from Planning Approval to the final build, completing the project in just six weeks. The result is a light-filled, modern home that strikes the perfect balance between independence and proximity to family.
This 50 sqm, three-room garden annexe in Kent, designed and built by Ark Design Build, meets the specific needs of the client. The annexe features an open-plan living area with a well-equipped kitchen, a bedroom with custom shelving around a pull-down bed, and large sliding and bi-fold doors that open onto a composite deck. The design thoughtfully maximises natural light while maintaining privacy. Known for their attention to detail, Ark Design Build managed the entire project, offering a full turnkey service from design and Planning to construction and final connections to mains services.
This 6m x 8.5m L-shaped garden annexe by Annexe Spaces is a cleverly designed home tailored for accessible living. Built for a young man, the annexe combines style and practicality across an open-plan layout that flows onto a level decked terrace. A wheelchair-friendly shower room is discreetly positioned in the corner of the L-shape, while the main living area includes a curtained sleeping zone and space for a home gym. Dark grey composite decking, low-threshold doors, and smart zoning make this compact annexe feel open and connected to the garden. Annexe Spaces handled the entire project, including mains connections and interior fit-out.
This 52 sqm L-shaped one-bedroom annexe, designed by Annexe Spaces, offers a comfortable and stylish living space tailored to the client’s needs. The design includes a double bedroom with fitted wardrobes and an en-suite shower room, alongside a U-shaped kitchen that opens into a bright living area with wide sliding doors leading to the garden. The exterior combines Thermowood cladding and cement fibre boards for a durable, low-maintenance finish. Annexe Spaces provided a comprehensive 'One Stop Shop' service, handling everything from design to final utility connections and Building Control sign-off.
This 52.25 sqm (9.5m x 5.5m) one-bedroom garden annexe by White Peak Design & Build features a bright, multifunctional kitchen-living area, a spacious bedroom, and an accessible bathroom. The design incorporates large feature windows that flood the living space with natural light, supported by a steel framework. The exterior combines dark grey cement fibre board with kiln-dried Western Red Cedar for a modern and sleek appearance. White Peak handled the entire project, including significant groundworks, delivering a fully move-in-ready home tailored to the client’s specific needs.
This 54sqm bespoke garden annexe, designed and built by Annexe Spaces, demonstrates how tailored living spaces can be created for future-proofed retirement living. Measuring 9m by 6m, this contemporary annexe was built under the Caravan Act with a Lawful Development Certificate, saving the client significant VAT costs. Designed in collaboration with the client, it features an L-shaped living area with a modern kitchen, a spacious bedroom with veranda access, and a fully equipped shower room. Annexe Spaces managed all aspects of the project, including planning and foundations, delivering a move-in ready home within 12 weeks.