While the concept of adding new living space to your home is exciting, the process of adding an extension is far from simple, involving careful planning, significant investment, and a lot of time.

We know the process can seem overwhelming, but that’s why we’re here to help. This guide will walk you through 32 essential tips, covering everything from budgeting to design and legal considerations, so you can bring your dream extension to life with confidence and ease.

1. Understand Why You Should Extend Your Home

When your family grows or your needs change, finding a new home might seem like the obvious solution. However, buying a new property can be costly, stressful, and time-consuming. From paying for Stamp Duty to moving costs, agent fees, and adjusting to an entirely new neighbourhood, the process can quickly become overwhelming.

Extending your home instead offers a simpler, more cost-effective alternative. By staying in the home and community you already know and love, you can avoid the hassle of uprooting your life and gain the space you need at the same time.

2. Understand the Type of Extension You Want

Before starting your project, it’s crucial to understand whether you want an extension or a replacement. An extension adds to the existing structure, while a replacement involves completely changing or rebuilding parts of your home. Clarifying this distinction early on will help you determine the scope of the project, ensure proper planning, and guide you in choosing the right materials and professionals.

Be specific about your needs to avoid confusion later on and make sure your dream project matches your expectations.

3. Consider What Else You Need to Think About

Before diving into the exciting world of home extensions, there are several key factors you must carefully consider to ensure the process runs smoothly. Taking the time to address these planning considerations early on will help you avoid costly mistakes and set a solid foundation for your project.

Value Impact

One of the first questions to ask yourself is how the extension will affect the value of your home. Will it add enough value to justify the cost of the build? Consider the size and scope of the extension. Will it enhance the overall functionality of your home and make it more desirable to potential buyers in the future?

Understanding the impact on your property’s value will help you make informed decisions about design, materials, and budget.

Foundation Strength

Before you start building, it’s essential to evaluate the strength of the ground your extension will be built upon. If your foundation isn’t solid enough, it could lead to structural issues down the line. Speak to a structural engineer to assess soil conditions and determine if any groundwork needs to be done to reinforce the foundation before construction begins.

Choosing Contractors

Selecting the right team to bring your vision to life is crucial. From architects and engineers to builders and subcontractors, the professionals you hire will play a significant role in the quality and timeline of your extension. Start early by researching and meeting with potential contractors, checking reviews, and requesting quotes. Identifying the right professionals from the start will save you time and avoid unnecessary stress as the project moves forward.

Wildlife and Environmental Considerations

When extending your home, it’s important to consider the impact your project may have on the surrounding environment. Are there trees or local wildlife in the area? Certain species, such as bats, birds, or even rare plants, may be protected by law. Before you start construction, check whether there are any wildlife protection regulations in your area that might affect your plans. You may need to adjust your design to preserve the natural environment and avoid causing harm.

Get Trusted Recommendations

One of the best ways to ensure a smooth extension process is by consulting others who have been through it themselves. Speaking to friends, family, or neighbours who have built extensions can provide invaluable insights into the challenges they faced, the services they used, and the mistakes they made. It’s also a good idea to speak to professionals who have experience with similar projects. They can offer advice and guidance on what to expect, what to avoid, and how to make the process as seamless as possible.

4. Look at How Much an Extension Will Cost

When considering a home extension, one of the first things you’ll need to figure out is how much it’s going to cost. The total cost of your extension can vary significantly depending on a range of factors, which may also differ depending on the type of extension you’re getting.

Single-Storey Extensions

For a single-storey extension, you can typically expect to pay anywhere between £1,000 and £3,000 per square metre. The exact cost will depend on the following factors:

Quality of Materials: Higher-end materials and finishes will naturally increase the cost. For example, choosing high-quality oak beams, custom flooring, or premium fixtures will raise the price.

Location: Costs can vary depending on where you live. For example, extensions in London or the South East tend to be more expensive than in other parts of the UK due to higher labour and material costs.

Design Complexity: A simple rectangular extension will cost less than a more complex design with multiple angles, large windows, or special features like a vaulted ceiling.

Two-Storey Extensions

Two-storey extensions generally cost a bit more than single-storey extensions, but the cost doesn’t double. Expect to pay between £1,800 and £3,500 per square metre. This price is higher due to additional structural elements required to support the upper floor, including:

Extra Structural Support: With two-storey extensions, you’ll need a stronger foundation, reinforced beams, and possibly additional planning considerations.

More Complex Roofing: A second storey requires a more complex roof design, which can increase costs.

Additional Finishes and Fixtures: With more living space comes additional requirements for plumbing, electrical work, and insulation, all of which add to the overall cost.

5. Think About How You’ll Finance the Extension

A home extension is a significant investment, and finding the right way to finance it is crucial for ensuring the project runs smoothly. Fortunately, there are several financing options available depending on the size of your extension and your personal circumstances.

Credit Cards: If your extension project is relatively small – perhaps a single-storey extension or a modest upgrade – using an interest-free credit card can be a great option.

Loans: If you need more funding than what a credit card can cover, a personal loan might be a good option. Personal loans typically offer larger sums of money, often up to £25,000, and can be paid off over a set period of time with a fixed interest rate.

However, keep in mind that loan repayments will be added to your monthly expenses, so be sure to calculate how much you can comfortably afford to repay.

Remortgaging: If your extension is a more substantial project, such as a two-storey extension or a major renovation, you may need to look at higher amounts of financing. Remortgaging or taking out a secured loan could be the right option.

Both options give you access to more significant funds, but they come with more financial responsibility, as failure to repay could result in losing your home.

6. Manage Your Payments Carefully

Managing payments effectively is crucial to avoiding financial stress during your extension project. Start by establishing a clear budget, including costs for materials, labour, and contingencies. Break payments into stages, such as a deposit, progress payments based on completed milestones, and a final payment upon project completion. Keep detailed records of all transactions and receipts to stay organised and track your spending.

Communicate openly with your contractor about payment schedules and potential extra costs, and be mindful of material costs by shopping around for the best deals. By staying on top of payments and being transparent, you’ll ensure the project runs smoothly without unexpected financial pressures.

7. Don’t Forget About VAT

VAT is zero-rated on new-build domestic properties, including self-builds, but this does not include extensions.

If the property has been empty for over two years, an extension will be considered a conversion, and VAT will be reduced to 5%. It’s important to ensure that your contractor is VAT-registered to take advantage of this concession. Always check your property’s eligibility and discuss VAT implications with your contractor to avoid unexpected costs.

8. Check if You Need Planning Permission

Depending on the scale and type of extension you are looking to build, you may or may not need planning permission.

Below is a list of some of the specifications and stipulations that determine whether or not you need planning permission:

You can extend a detached dwelling by 8m to the rear if it’s single-storey or 3m if it’s double.
There are height restrictions. A single-storey extension not being higher than 4m in height to the ridge and the eaves, and ridge heights of any extension not being higher than the existing property.
Two-storey extensions must not be closer than 7m to the rear boundary.
It must be built in the same or similar material to the existing dwelling.
Extensions must not go forward of the building line of the original dwelling.
Side extensions must be single-storey, with a maximum height of 4m and a width of no more than half the original building.
In Designated Areas side extensions require planning permission and all rear extensions must be single-storey.
An extension must not result in more than half the garden being covered.
You can only extend a building once if the original building is either as it was on the 1st of July 1948 or when it was built. In Northern Ireland, this cut-off point is on the 1st of October 1973.

Our Planning Service can offer help, guidance, and support with planning applications as necessary.

9. Check if Your Property is a Listed Building

A listed building, or listed structure, has been placed on one of the four statutory lists maintained by Historic England in England, Historic Environment Scotland in Scotland, Cadw in Wales, and the Northern Ireland Environment Agency in Northern Ireland.

Listed buildings are protected due to their historical or architectural significance. Any alterations or extensions must preserve their character and require permission to be carried out. It’s a criminal offence to make the alterations without permission.

You will need to apply for Listed Building Consent, in addition to regular Planning Permission, and work closely with heritage specialists to ensure that the extension complies with regulations. It’s important to start the process early and seek expert advice to avoid any legal or compliance issues.

10. Look Up Local Authority Grants

Local authority grants for home extensions are rare but worth inquiring about, especially if your property requires extensive work. Some grants may be available for properties in poor condition or for projects that improve the building’s accessibility or energy efficiency. It’s always a good idea to check with your local authority to see if you qualify for any financial assistance or support before proceeding with your extension plans.

11. Check Building Regulations

Building Regulations ensure that your extension meets necessary safety and structural standards. These regulations cover everything from foundations and electrical systems to insulation and fire safety.

Regardless of whether Planning Permission is required, your extension must comply with Building Regulations. It’s essential to work with a qualified contractor who understands these requirements and to have your project inspected at key stages to ensure full compliance and avoid potential issues down the line.

12. Decide if it’s Worth Getting a Warranty

While not essential, getting a warranty for your extension can provide valuable peace of mind. A warranty ensures that any defects or damages in the work can be repaired without added stress or cost. This is especially helpful if issues arise after the project is completed. It’s worth considering a warranty to protect your investment and ensure the quality of the work in the long term.

13. Think on How You Want to Design Your Extension

Designing your extension is a crucial step in the process. To ensure it maximises space, meets Building Regulations, and aligns with your vision, consider working with a structural engineer or architect. These professionals can help bring your ideas to life while ensuring that your design is practical, safe, and compliant. Their expertise will ensure that the design process is smooth and that the final result meets both your needs and expectations.

14. Decide If You Want to Use an Architect

An architect can play a key role in turning your vision into reality. With their expertise, they can provide creative solutions that seamlessly blend your extension with your existing home. Architects offer unique design ideas that enhance functionality, aesthetics, and value while ensuring compliance with Building Regulations.

Architectural technologists could be consulted for smaller-scale extensions as they would have all the necessary knowledge and experience to deal with extensions or projects that are smaller in nature.

In order to be a fully qualified architect, the person needs to complete the RIBA Part111 Professional Practice Exam, which is the final part of an architect’s training.

15. Find the Right Architect or Designer

When searching for the right architect or designer, start by seeking recommendations from trusted sources such as friends, family, or colleagues who have worked with one before.

Ensure that the architect you choose has the necessary qualifications and expertise in extension projects. Look for professionals who are RIBA-registered (Royal Institute of British Architects) or part of other reputable organisations, such as:

Royal Institution of Chartered Surveyors (RICS)
Chartered Institute of Architectural Technologists (CIAT)
Association of Building Engineers (ABE)
Chartered Institute of Building (IOB)
Institution of Structural Engineers (ISE)

16. Decide Who Will Manage the Work

Deciding who will manage your extension project is an important step. You can either hire a project manager to oversee the various stages of construction, coordinate contractors, and ensure timelines are met, or opt for a design-build company that offers both design and construction services under one roof.

A design-build company can simplify the process by handling everything from planning to execution, while a project manager allows you to maintain more control over choosing separate contractors. Choose the option that best fits your needs, budget, and level of involvement.

17. Find the Right Builders and Tradesmen

Taking the time to find reliable and experienced professionals is crucial for the success of your extension. A good builder and skilled tradesmen will ensure the work is completed to a high standard, on time, and within budget. Start by asking for recommendations from friends, family, or past clients, and always check reviews and credentials.

Be sure to vet potential builders by looking at their previous work, confirming they have the right qualifications, and discussing your project in detail. If you don’t have anyone in mind, English Heritage Buildings can also recommend contractors to you, in order to complete an oak-framed extension we’ve made for you.

18. Consider Safety and Potential Disruptions Onsite

Maintaining a safe and tidy worksite is essential not only for the safety of the workers but also to minimise disruption to your daily life. Ensure that your contractor follows proper safety protocols, uses appropriate equipment, and keeps the site organised to avoid accidents and unnecessary delays.

Communicate your expectations for cleanliness and set boundaries to keep areas of your home free from construction-related mess. A well-managed site will not only ensure safety but also reduce the impact of noise and dust on your daily routine, helping the project run smoothly and with minimal inconvenience.

At the same time, many professionals recommend ensuring you build a rapport with the people you’ve hired. Provide them with the correct facilities to make their job as comfortable and easy as possible, including light refreshments and a toilet for comfort breaks, and trust them to follow the instructions you’ve set out.

19. Should You Move Out While Extending?

Deciding whether to stay in your home during the extension process or move out depends on the scale of the project and your comfort. If the work involves significant disruption, such as loud noises or safety concerns, it might be best to find temporary accommodation to avoid stress.

However, if the work is confined to one area and won’t interfere too much with your daily life, staying at home could save you the hassle and the cost involved in finding a hotel, or in moving in with friends or relatives temporarily. Weigh the pros and cons to determine what will make the process as smooth and comfortable as possible for you and your family.

20. Get the Brief Right

When planning your extension, it’s essential to have a clear and specific idea of what you want. Simply saying you want more space can be too vague, leaving too much room for interpretation. Think about exactly what you need; whether it’s a larger kitchen, an additional bedroom, or a home office in a particular part of your house. The more detailed you can be, the better.

Even if your ideas seem unconventional, don’t hesitate to share them. The clearer you are in expressing your vision, the more accurately architects or designers can create a plan that brings your dream extension to life.

21. Choose the Right Materials

When selecting materials for your extension, it’s important to strike a balance between quality, price, and aesthetics. Opt for materials that not only look good but are also durable and cost-effective in the long run. Consider how the materials will hold up over time and whether they’ll need frequent maintenance.

Additionally, design integrity should guide your choices. Ensure the materials complement the existing structure of your home, maintaining its character and blending seamlessly with the overall design. By carefully selecting the right materials, you’ll enhance both the function and appearance of your extension.

22. Consider the Size of Your Extension

When planning your extension, it’s essential to focus on creating the right amount of space. Adding too much space can overwhelm the existing structure and feel out of place, while too little may not meet your needs. A balanced size that complements your home will add value and enhance comfort without making the space feel crowded or excessive.

23. Always Plan for Storage

Storage is often overlooked during the design phase, but it’s an essential part of making your extension both functional and organised. Think about how you will store your belongings, whether it’s through custom shelving, hidden cabinets, or built-in wardrobes. Incorporating storage solutions into your extension ensures that the space remains tidy and efficient, especially if you’re adding extra living or work areas.

24. Should You Follow the Same Architectural Style?

When extending a building, it’s important to consider its architectural style. Many older homes, such as Georgian, Tudor, Victorian, and Edwardian, carry a unique historical significance. By extending in a way that complements this style, you can enhance the building’s originality without detracting from its character. Adding your own touch is great, but it’s crucial to maintain respect for the existing design to keep the extension harmonious.

Imagine a Victorian building extended in the same Victorian style but updated to suit modern needs. It’s a perfect balance of tradition and innovation. Ultimately, you can add more space and functionality without compromising the charm of your home.

25. Use Your Imagination

When designing your extension, don’t be afraid to let your creativity shine. Think outside the box and explore innovative ways to use the space efficiently. Whether it’s creating multi-functional areas or incorporating unique features, an imaginative approach can turn your extension into a standout part of your home. Embrace bold ideas that not only meet your practical needs but also reflect your personal style, ensuring that the space is both functional and inspiring.

26. Don’t Forget to Consider Landscaping

When planning your extension, consider how the natural surroundings can enhance your space. Building around existing trees, plants, and natural features can add beauty, charm, and value to your property.

By integrating the landscape into your design, you create a seamless flow between indoor and outdoor areas. This thoughtful approach can turn your extension into a more inviting and harmonious part of your home, making the most of the environment around you.

27. Remember: Simplicity is Key

Simplicity is often the key to elegance and functionality. When designing your extension, avoid overcomplicating the project with unnecessary details. A clean, straightforward design will not only be more cost-effective but also more practical and timeless. Focusing on what truly adds value and purpose to your space will ensure your extension complements your home without overwhelming it.

28. Measure and Plan as Much as You Can

Thorough and accurate planning is essential to the success of your extension. Measure and double-check everything to ensure precision in your design and material requirements. Taking the time to carefully plan now will help you avoid costly mistakes and delays later on. The more detailed your planning, the smoother the construction process will be, ensuring your extension meets your expectations without unnecessary setbacks.

29. Reuse, Recycle, and Repair

Being mindful of sustainability is essential when planning your extension. Reusing and recycling materials not only reduces waste but also makes your project more eco-friendly. By incorporating reclaimed materials or repurposing existing structures, you can create a beautiful, efficient extension that benefits both your home and the environment.

Small efforts, like repairing materials instead of discarding them, can also add character and charm to your extension while keeping it environmentally conscious.

30. Add Energy-Efficient Features

Alongside recycled materials, incorporating energy-efficient features into your extension can provide long-term savings and contribute to a more sustainable home. Consider adding high-performance windows, insulation, and energy-efficient appliances to reduce energy consumption and lower your utility bills. These small investments not only benefit the environment but also help create a more comfortable living space. By prioritising energy efficiency, you’ll enjoy a more eco-friendly and cost-effective home for years to come.

31. Think About Futureproofing

When planning your extension, consider how it will adapt to your future needs. Include flexible spaces that can serve different purposes over time, such as a home office that could later become a guest room. Additionally, think about energy-efficient upgrades like solar panels, improved insulation, or smart home features to ensure your extension remains sustainable and cost-effective in the years ahead.

By planning for the future, you can create a space that not only meets your current needs but also remains practical and efficient as your lifestyle evolves.

32. Be Realistic About Timelines

While it’s exciting to see your extension come to life, it’s crucial to be realistic about timelines. Construction projects often take longer than expected due to unforeseen delays or complications. To avoid frustration, build in extra time for potential challenges, such as weather delays or supply shortages. Allowing flexibility in your timeline will ensure that the project is completed to your satisfaction without unnecessary stress, helping you stay focused on the end result.

Extend Your Home, Just as You Want

Building your dream extension can be a smooth and rewarding journey when you plan carefully and follow the right steps. With these 32 tips, you’re well-equipped to create a space that perfectly meets your needs while enhancing the beauty and functionality of your home.

Ready to build your dream extension? Contact us today for expert advice, design services, and the highest-quality oak-framed extensions that will add both value and beauty to your home. Alternatively, request a copy of our brochure and see what else we can do for your home.

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A Specialist’s 32-Tip Home Extension Guide