Under Garden Basement

by | Jul 25, 2023 | House Extension | 0 comments

Are you dreaming of expanding your living space without sacrificing your beautiful garden? Well, we have some exciting news for you! You can now build an under garden basement extension right under your garden! In this article, we’ll walk you through the entire process, from the multiple uses of garden basements to the cost, regulations, and even building on a budget. So, grab a cuppa, and let’s dive in!

Multiple Uses for Basement Extensions Buried Beneath Your Garden

Basement extensions buried beneath your garden offer a plethora of versatile and exciting uses. Let’s explore some of the multiple ways you can make the most of this underground garden room:

Extra Living Space

One of the most common uses for an under garden basement extension is creating additional living space. You can design a comfortable and cosy living area, complete with a lounge, dining room, and even a kitchenette. This extension can serve as a perfect space for family gatherings, entertaining guests, or simply relaxing.

Home Office or Study

With the rise of remote work and the need for dedicated workspaces, an under garden basement can be transformed into a peaceful home office or study. This secluded underground garden room setting provides a quiet environment, minimising distractions and enhancing productivity.

Home Gym

Transform your under garden basement into a private fitness haven by setting up a home gym. You can install exercise equipment, mirrors, and proper ventilation to create an inspiring space for your workouts. The added benefit of being underground is better sound insulation, allowing you to exercise without disturbing the rest of the household.

Guest Suite

A basement extension can serve as a luxurious guest suite, providing a private and comfortable space for visitors. You can include a bedroom, bathroom, and a small living area, ensuring that your guests feel welcomed and pampered during their stay.

Home Cinema or Entertainment Room

Create the ultimate cinematic experience by turning your under garden basement  into a home theatre. Install a large screen, surround sound system, and comfortable seating to enjoy movie nights with family and friends. It’s an excellent way to unwind and escape into a world of entertainment without leaving your home.

Wine Cellar

Wine enthusiasts will delight in the idea of a basement wine cellar. With proper temperature and humidity control, your basement can become the ideal storage space for your wine collection. You can also add a tasting area for an elegant touch.

Art Studio or Hobby Room

If you have a creative side, a basement extension can be converted into an art studio or hobby room. Whether you’re into painting, crafting, woodworking, or any other hobby, having a dedicated space to indulge in your passion is invaluable.

Storage Space

Basements are a natural choice for additional storage. You can organise the area with shelves, cabinets, and storage units to keep seasonal items, rarely used belongings, and other household essentials neatly tucked away.

Playroom or Children’s Area

For families with kids, a basement can be transformed into a designated playroom or children’s area. It offers a safe and spacious environment for children to play, explore, and have fun, especially during unfavourable weather conditions.

Rental Apartment or Airbnb

If you’re looking to generate extra income, consider turning your basement extension into a rental apartment or an Airbnb unit. It can be a source of passive income while utilising the space efficiently.

Benefits of Extending Your Home Under Your Garden

Extending your home under your garden by building a basement offers a wide range of benefits that make it an appealing option for homeowners. Let’s delve into the advantages of this unique home expansion:

Increased Living Space

The most obvious benefit of building an under garden basement extension is the substantial increase in living space without expanding the footprint of your house. It allows you to add multiple rooms and create functional areas that cater to your specific needs, whether it’s for extra bedrooms, a home office, or recreational spaces.

Preserves Garden and Outdoor Space

Unlike traditional above-ground extensions, building under your garden preserves the outdoor space and aesthetics of your property. Your garden remains intact and retains its natural beauty, making it a peaceful oasis where you can relax and unwind.

Minimal Disruption

Excavating and constructing the basement extension underground causes minimal disruption to your daily life compared to above-ground extensions. It reduces noise and visual disturbances during the construction process, allowing you to carry on with your routine more comfortably.

Privacy and Sound Insulation

An under garden basement provides enhanced privacy from the outside world. It acts as a natural sound barrier, reducing noise from the surrounding environment and improving the tranquillity of your living spaces.

Unobstructed Views

By extending your home underground garden room, you maintain unobstructed views from the existing windows and the surrounding areas. You can enjoy the beautiful scenery and natural light without any alterations to the exterior of your property.

Energy Efficiency

Basements have natural insulation from the surrounding soil, which helps regulate the temperature inside the space. This natural insulation can lead to improved energy efficiency and lower heating and cooling costs over time.

Flexible Design Options

Building under your garden allows for more flexibility in design and layout. You can customise the basement to suit your unique preferences, incorporating innovative design elements that might be challenging to implement in above-ground extensions.

Increased Property Value

Adding a basement extension can significantly increase the value of your property. The additional living space and functional versatility of a basement make it an attractive feature for potential buyers and can result in a higher resale value.

Home Safety and Security

Basements can serve as safe rooms during severe weather events, providing a secure shelter for your family. Additionally, building underground can deter potential intruders, adding an extra layer of security to your home.

Planning regulations and obtaining necessary permits

Building a basement under your garden? Here’s the permit situation sorted:

Council Rules

Every council has its own basement building rules. Know them before you start digging to avoid delays, fines, or even a big fat no.

Planning Permission Needed

Get permission from your council before breaking ground. It takes time (weeks or months), so plan ahead.

Conservation Area Restrictions

Extra hoops to jump through if you’re in a conservation area. Make sure your basement plans fit the area’s vibe.

Protected Trees

Got a tree with a fancy order protecting it? Your basement plans will need to work around it.

Chat with the Neighbours

Be a good egg and tell your neighbours about your plans. Addressing any worries early can avoid headaches later.

Get Expert Help

Building regs and permits can be tricky. Consider hiring an architect, engineer or project manager to guide you through the process. They can save you time, money, and hassle.

Challenges of Building an Under-Garden Basement

Adding a basement under your garden, while brilliant for creating more space and boosting your property value, comes with a fair few hurdles to jump. Let’s break down the key challenges the blog mentioned:

Planning Permission Palaver

Every council has its own set of rules on building basements, especially ones under gardens. These rules might limit the depth you can dig or the size of the basement itself, so you’ll need to factor that in during the planning stage and be quite creative with the design.

Conservation Area Cobwebs

If you live in a conservation area, get ready for some extra hoops to jump through. There might be stricter rules on building basements to protect the area’s character. Think preserving trees and following specific building styles.

Surveys and Techy Talk

Before you even get to the design stage, you’ll need to get some surveys done. These will check the soil type, drainage systems, and if digging might affect your neighbours’ foundations. This is important to ensure your basement’s design is sound and to avoid any nasty surprises later on.

Building a Waterproofing Wonder

Designing a basement that’s both structurally strong and completely waterproof is absolutely crucial. If water gets in, it can cause a whole heap of problems, like damaging the structure and costing a small fortune to fix.

Contractors You Can Count On

Finding the right builders for both the main construction and the finishing touches is key. You’ll need a team with specialist knowledge of basements to make sure everything’s done safely and to a high standard. Juggling multiple contractors and keeping the whole project running smoothly can be a right headache too.

Project Management

The Juggling Act: The entire process, from the very beginning to the grand finale, needs to be meticulously managed. This means keeping everyone involved on the same page, getting all the necessary permissions, and making sure everything follows building regulations. It’s a lot to keep track of.

A Step-by-Step Guide to Building a Basement Extension

Now, let’s get to the exciting part – building your dream under garden basement extension! 

Step 1: Assess property feasibility and consult with professionals.

Step 2: Collaborate with an architect to design the basement extension.

Step 3: Obtain necessary permits and approvals.

Step 4: Hire licensed contractors for excavation and construction.

Step 5: Waterproof and install proper drainage systems.

Step 6: Set up essential utilities like electricity and plumbing.

Step 7: Construct foundation walls and load-bearing elements.

Step 8: Complete interior finishing, including walls and flooring.

Step 9: Install electrical and plumbing fixtures as per the plan.

Step 10: Implement proper ventilation and HVAC systems.

Step 11: Ensure safety measures and compliance with regulations.

Step 12: Schedule inspections and obtain final approval.

Step 13: Furnish the basement and add personal touches.

Step 14: Perform final checks and clean-up.

Enjoy your new functional basement space!

How Much Will an Under-Garden Extension Cost in the UK?

The budget question! The cost of your under garden basement extension depends on various factors, including the size, location, and complexity of the project. On average, you can expect the cost to range from £2,000 to £3,000 per square metre. However, keep in mind that these are just estimates, and the actual basement cost might vary. To manage your finances better, we recommend obtaining multiple quotes from different contractors and budgeting for potential contingencies.

Regulations for Building a Basement UK

Before you start digging, let’s talk about regulations. In the UK, under garden basement constructions are subject to building codes and regulations, just like any other building project. It’s crucial to ensure compliance to avoid legal complications down the road. 

Hiring licensed professionals who are well-versed in these regulations will give you peace of mind and guarantee a safe and successful project.

Can You Build a Basement Under an Existing House?

The answer is yes, but it’s essential to consider the feasibility. Retrofitting an existing house with a basement might be more complex and costly than building an under garden basement for a new construction. It requires thorough planning and expert guidance to ensure structural integrity and avoid any potential issues.

Do You Need Planning Permission to Build Underground?

This is a common concern for homeowners. In some cases, you might be able to take advantage of permitted development rights and construct your basement without planning permission. However, depending on your location and the size of the project, you may need to apply for planning permission. It’s best to consult with your local planning authority to determine the specific requirements for your area.

How to Create a Basement on a Budget

Creating a basement on a budget requires careful planning, resourcefulness, and a willingness to explore cost-effective options. Here are some practical tips and strategies to help you build your dream under garden basement without breaking the bank:

Simple Design and Layout

Opt for a straightforward and efficient design that maximises the use of space without unnecessary complexities. A simple rectangular layout can help reduce construction costs and make the best use of materials.

Strategic Excavation

Minimise excavation costs by carefully planning the depth and size of your basement. A shallow basement requires less digging and backfilling, resulting in lower expenses.

Reuse and Recycle

Look for opportunities to reuse or recycle materials. For instance, if you have leftover construction materials from previous projects, such as bricks, concrete blocks, or timber, consider repurposing them for your basement construction.

Use Affordable Building Materials

Instead of expensive high-end materials, choose cost-effective alternatives that still offer durability and functionality. For instance, engineered wood can be a more affordable option for flooring, and vinyl or laminate flooring can mimic the look of more expensive materials like hardwood or stone.

Get Multiple Quotes

Obtain quotes from multiple contractors and suppliers to compare prices. This will give you a better understanding of market rates and help you negotiate a competitive deal.

Negotiate with Contractors

Don’t hesitate to negotiate with contractors to get the best prices for their services. Many contractors are willing to work within a budget and might offer cost-saving suggestions.

Plan for Energy Efficiency

Investing in energy-efficient features during construction may have higher upfront costs but can result in significant long-term savings on utility bills. Proper insulation, energy-efficient windows, and LED lighting are some examples.

Choose Value-Engineering

Collaborate with your architects and contractors to explore value-engineering options. Value engineering focuses on finding cost-effective alternatives that meet the same functionality and quality standards.

Prioritise Must-Haves

Identify the essential elements of your basement project and prioritise them. If you’re on a tight budget, focus on the critical aspects first and consider adding non-essential features later as funds allow.


Congratulations! You’ve just taken a significant step towards expanding your home with a stunning basement beneath your garden. Remember, thorough planning, compliance with regulations, and budget-conscious decisions are the keys to a successful project. 

So, go ahead and turn your dreams into reality with an under garden basement extension that will add value, functionality, and joy to your home for years to come! Happy building!


Emmanuel Nwaebo

Emmanuel Nwaebo is the Managing Director at Powerpillar Ltd and has more than 25 years experience in building construction and renovations. He has a bachelor’s in Electronics and Electrical Engineering with certification in Construction Health and Safety Technician (CHST). With an experience in managing construction and renovation services for years, he is extremely passionate about property management and loves helping people find their dream property.

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