Single Story Extensions - More Space, Less Stress
Single story extensions add more space without the hassle of moving. They can transform a home by creating a larger kitchen, open-plan living area, or extra rooms tailored to your needs.
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Types of Single Story-Extensions
Single story extensions come in a variety of styles, each offering different benefits depending on your space and needs. To find out more about the areas we cover, click here. For single story extensions, some popular options include:
Rear Extensions
Side Extensions
Wraparound Extensions
Flat Roof Extensions
Pitched Roof Extensions
Porch Extensions
Garage Conversions
Outbuildings/Annex
Choosing the right single story extension
Understanding the different types of single story extensions will help you make an informed decision. From rear extensions that open up your home to side extensions that make use of unused space, each option is designed to meet different needs. Some extensions are best suited for large gardens, while others are perfect for homes with limited outdoor space. Below, we explore the various types of single story extensions to help you find the right solution for your home.
Rear Single-Story Extensions
A rear single story extension provides additional space by extending into the garden, creating an open-plan kitchen, living area, or home office. Before starting, it’s important to have planning permission, building regulations, and party wall matters in place.
Permitted Development
Many extensions fall under permitted development, with terraced and semi-detached homes allowed up to 3m or up to 6m with prior approval. Detached homes can extend up to 4m under permitted development or up to 8m with prior approval. Larger extensions require full planning permission, and an architect can help streamline the process.
Side Single-Story Extensions
A single story side extension is a great way to utilise unused land, whether to expand a kitchen, create a new living area, or add a utility room. Many homeowners choose to knock down internal walls, opening up the space to form a larger kitchen-dining area or a seamless extension of the existing living room. Others opt for a side infill extension, transforming narrow side spaces into practical areas for dining, entertaining, or everyday use.
Other Options
A side extension can also serve as a utility room, offering extra storage and space for laundry appliances. Maximising natural light is key, with skylights, glass doors, and large windows helping to brighten up the space. Designed well, a side extension not only improves functionality but also adds significant value to a property.
Wrap Around Extensions
Wraparound extensions make use of both the side and rear of a property, forming an L-shaped space that maximises the home’s footprint. Often found in period properties with side alleyways, this type of extension transforms underused areas into functional living space. It provides room for larger kitchens, playrooms, or utility areas while improving the connection between indoor and outdoor spaces.
Natural Light
Enhances through clever design, making the home feel more open and spacious. Costs for a 45 sqm wraparound extension typically range from £75,000 to £145,000 in London and £60,000 to £120,000 elsewhere, depending on materials, contractors, and structural work required. Additional expenses such as VAT, glazing, kitchens, and professional fees should also be factored into the budget. With the right planning, a wraparound extension can add significant value to a property while making better use of available space.
Flat Roof Single-Story Extensions
Flat roof single story extensions are a modern and cost-effective way to expand your home. Unlike pitched roofs, flat roof extensions require fewer materials, making them a more affordable option while also being quick to construct. Their sleek, horizontal design allows them to fit into tighter spaces without the need for angled sides, making them ideal for urban homes with limited room to extend.
Low Maintenance & Cost Efficiency
Flat roofs are easy to maintain and require minimal upkeep, with materials like EPDM, felt, and fibreglass providing durable protection. Costs typically range from £50 to £120 per square metre, depending on the material chosen. While flat roof single story extensions generally fall under permitted development, they must meet building regulations, particularly in regard to height restrictions and visibility from public roads.
Pitched Roof Single-Story Extensions
A pitched roof single story extension is a great way to increase space while maintaining a traditional and visually appealing design. Often preferred by planning departments, pitched roofs blend seamlessly with existing homes, making them a popular choice for extensions. They offer improved energy efficiency, as the sloped design allows for better insulation compared to flat roofs. Their shape also enhances durability by preventing water accumulation, reducing the risk of leaks.
Higher Ceilings & Architectural Appeal
A key advantage of pitched roof extensions is the increased ceiling height, which creates a more spacious feel and allows for architectural details such as exposed beams. There are various pitched roof designs, including gable roofs, hipped roofs, and single-slope roofs, each offering unique benefits in terms of aesthetics and structural performance. With the right design, a pitched roof single story extension can enhance both the functionality and character of your home while adding long-term value.
Porch Extensions
A single story porch extension is a simple yet effective way to enhance your home’s entrance, providing extra space for storage while improving curb appeal. Many homeowners choose to add a porch extension to create a sheltered entryway, making it easier to store coats, shoes, and other essentials while offering protection from the elements.
Two Main Options
A porch is also a great addition to single story extensions, helping to create a more defined and practical entrance space. There are two main options: open porches, which provide a decorative feature and a convenient covered area, and enclosed porches, which act as a functional entrance space with added security. Most small porches fall under permitted development, meaning planning permission is not required as long as they remain within size limits. When designed well, a porch extension complements single story extensions, improving both functionality and visual appeal.
Garage Conversions
A garage conversion is a cost-effective way to increase living space without extending into the garden. Unlike traditional single story extensions, a garage conversion repurposes existing space, making it a quicker and more affordable option for homeowners. Many conversions require minimal structural work, making them ideal for creating an extra bedroom, home office, gym, or even an open-plan kitchen extension.
Approvals & Building Regs
Planning permission is often not required, as most garage conversions fall under permitted development, but building regulations must still be met. When designed well, a garage conversion can blend perfect with single story extensions, improving both the function and value of a home. We offer expert garage conversion design across the whole of Essex, including areas such as Chelmsford, Brentwood, Billericay, Southend, Hornchurch, Grays and Rayleigh.
Outbuildings & Annex Extensions
An annex or outbuilding is a versatile home addition that can serve as a great option for single story extensions, from a guest bedroom, home office to a private gym or self-contained living space. Unlike traditional single story extensions, these structures can be either connected to the main house or stand alone.
Planning Permission
While planning permission may be required based on size and usage, many annexes still fall under permitted development. When thoughtfully designed, an annex or outbuilding can serve many purposes and is usually relatively easy to gain permission for.
Start Your Home Extension the Right Way
A single story extension adds valuable space to your home, but knowing where to start can be confusing. Should you speak to an architect or a builder first? Many turn to design-and-build companies, only to find that architectural work is outsourced and sometimes designed to maximise builder profits—not your home’s potential.
Expert Guidance from Day One
At Kirkwood, we’re your first point of contact, ensuring your extension is designed properly, structurally sound, and fully approved before a builder even gets involved. This means no costly surprises, no cutting corners—just a well-planned extension that meets your needs and budget.
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Based in Brentwood, Essex, we were also introduced to builders and tradespeople through Kirkwood, and they were excellent—professional, respectful, and a pleasure to work with. If we ever take on another project, we wouldn’t hesitate to use them again.
We now have an amazing extension, and would be happy to use the team again.
Very knowledgeable and contactable throughout the process.
Couldn't ask for a better outcome and value for money.
Will definitely be recommending and 100% will use again!
5 star!!!
Areas We Cover in Essex
We’re proud to help homeowners all across Essex. Some of the areas we serve include:
Frequently asked questions
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What size of single storey extension qualifies as permitted development?
Permitted development (PD) rules allow certain single storey extensions without full planning permission. Typically, this means a rear extension up to 3 to 4 metres for terraced and semi-detached homes, and up to 6 metres for detached houses. At Kirkwood, we’ll help you understand if your project qualifies during our free consultation.
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How much does a single storey extension usually cost?
Costs vary depending on size and specifications, but a single storey extension generally ranges from £20,000 to £50,000. Kirkwood provides tailored architectural plans that help you maximise your budget while ensuring design quality and compliance.
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Do I need planning permission for a single storey extension?
Whether you need planning permission depends on the size and location of your extension and local council rules. Kirkwood’s architects are experienced in Chelmsford and Essex regulations and will guide you through this process during your free consultation.
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How long does it take to complete a single storey extension project?
From design to build completion, a single storey extension can take between 3 to 4 months on average. Kirkwood handles architectural design and planning support efficiently to help minimise delays and keep your project on schedule.
