The housing landscape is changing, and with it, the shape of the family home. It is increasingly common for adult children to live with their parents longer as they navigate a challenging property market. This trend often leaves families searching for ways to create more space, and two popular solutions emerge: building a garden room or extending the existing house.
Deciding which path to take is a significant decision. Both options come with their own set of advantages and challenges, from costs and construction time to planning permission and long-term value. This guide will walk you through the key considerations, comparing a garden room against a house extension to help you determine the best fit for your family’s needs, budget, and future plans.
The Case for a Garden Room
A garden room is a standalone structure built in your garden, separate from the main house. Often manufactured off-site, these rooms have become a popular choice for those needing extra space quickly.
Pros of Building a Garden Room
- Cost-Effective: In most cases, a garden room is significantly cheaper than a full house extension. The construction is less complex and doesn’t require interfering with the main house structure, which helps keep costs down.
- Faster Construction: Many garden rooms are prefabricated and can be installed in a matter of days or weeks, causing minimal disruption to your daily life.
- Privacy and Separation: The physical separation from the main house can be a major advantage. It offers privacy for both parents and adult children, creating a distinct space for work, relaxation, or independent living. This separation can be ideal for a home office, a den, or a teenager’s retreat.
- Versatile Use: A garden room can serve multiple purposes. It might be a living space for a family member today and a home office, gym, or studio tomorrow, adapting to your family’s changing needs.
Cons of Building a Garden Room
- Planning Permission: This is a crucial point. Contrary to some beliefs, there are currently no planning exemptions for habitable rooms in domestic gardens. Many garden rooms are advertised as “exempted developments,” but this typically applies only if they are classified as non-habitable storage sheds under 25 square metres. Using one as a full-time living space requires planning permission, which can be difficult to obtain.
- Limited Lifespan: Many garden rooms are built with lightweight materials and may have a shorter lifespan than a block-built house extension.
- Space Limitations: Building a garden room means sacrificing a portion of your garden. If your outdoor space is already limited, this could be a significant drawback.
- Aesthetic Impact: While many designs are sleek and modern, a poorly placed or designed garden room can detract from the overall look of your property and garden.
The Argument for a House Extension
A house extension involves adding a new room or structure that is directly attached to your existing home. This is a more traditional approach to creating extra space.
Pros of Extending Your House
- Increased Property Value: A well-designed extension almost always adds significant value to your property. It increases the total square footage and seamlessly integrates with the existing home.
- Seamless Integration: An extension becomes a true part of your home. It allows for a natural flow between old and new spaces, which can be ideal for creating larger, open-plan living areas.
- Long-Term Durability: Built with the same materials and standards as the main house, an extension is a permanent, durable structure designed to last for decades.
- Greater Functionality: Extensions offer more flexibility in terms of design and use. You can create a new kitchen-diner, add a second living room, or build an extra bedroom and bathroom, all connected to the main house’s utilities.
Cons of Extending Your House
- Higher Cost: Extensions are a major construction project and are considerably more expensive than building a garden room. Costs include architectural design, materials, labour, and potentially extensive structural work.
- Longer Construction Time: An extension can take months to complete, from the initial design phase to the final touches. This prolonged period can cause significant disruption to your home life.
- Planning Permission Challenges: While some smaller extensions may fall under exempted development, larger or more complex projects will require full planning permission, which adds time and uncertainty to the process.
- Disruption to Daily Life: Living in a building site is not easy. Noise, dust, and a constant stream of tradespeople can be stressful and disruptive for the entire family.
Planning Permission and Regulations Explained
Understanding the legal requirements is the most critical step. As chartered building surveyor Val O’Brien notes, planning authorities are often reluctant to grant permission for a second habitable unit in a private garden.
Most garden rooms are marketed as exempt from planning permission, but this is on the basis that they are classed as a store or shed (under 25 sq m) and are not used for habitable purposes. If you intend for your adult child to live in the garden room, it is classified as a habitable space and will require planning permission. Proceeding without it could lead to legal complications and a request to remove the structure.
House extensions also have rules. While there are exemptions for small rear extensions (typically up to 40 sq m), these come with strict conditions regarding height, proximity to boundaries, and more. It is essential to consult with a professional to confirm whether your project requires permission.
Making the Right Choice for Your Family
The decision between a garden room and a house extension depends entirely on your specific circumstances, priorities, and long-term goals.
A garden room might be the perfect solution if your primary need is a separate, functional space like a home office or a part-time den, and you want to manage costs and disruption. It can provide a quick and convenient solution to an immediate need for space.
However, if you are looking for a long-term, integrated living solution that will add lasting value to your home, a house extension is likely the better investment. It provides a permanent, durable addition that becomes a seamless part of your family home.
Before making any decision, it is crucial to seek professional advice. A chartered building surveyor or architect can assess your property, analyse your requirements, and guide you through the complexities of planning permission and building regulations.
If you are considering adding space to your home and need guidance on the legal aspects of property law and conveyancing, our team at HOMS Assist is here to help. Contact us today for expert legal advice to ensure your project moves forward with confidence.
