How To Build An Under Garden Basement in London

When most people need extra space in their home, they think about a loft conversion or extension. But there is another option that many people don’t know about – building a basement under the garden. This type of extension is a fantastic way to use dead space on your property and get the extra room your family needs. In this step by step guide to building an extension under your garden, you’ll learn everything you need to know to get started.

Benefits Of Having An Under Garden Basement

As well as adding value to the home, there are other great benefits of having an under garden basement:

  • They allow more light in than traditional basements. This is because you can add more windows.
  • You can easily ventilate the area with fresh air through open doors.
  • They can be made larger than a regular basement, giving you bonus space.
  • They are inconspicuous as they are under your garden.
Under garden basement entertainment room with pool table and bookshelves
Photo by Luke Davies on Unsplash

Cost of Building a Basement Extension

The cost of building a basement under your garden in the UK can vary greatly depending on the size required and garden. However, since there is no underpinning required, it can be as much as half the cost of an under property basement, making it a great option to consider.

Costs of the add-on

Things that will impact on the cost include: 

  • The size you want the basement to be
  • The external access you have to the garden – poor access can bump up the cost 
  • Garden soil type – certain soils and a high water table can also drive up the cost. 

Additional garden basement room costs include architect fees if you need one, structural engineer fees, planning applications and surveys. 

In general, the cost of a basement conversion in London is between £4,000 and £6,000 per square metre.

Regulations for Building a Basement

Different authorities will have different policies outlining planning permission for under garden basements. It’s vital to know what you can and can’t do and what design is feasible and effective, so make sure you’re familiar with your local policies. 

For example, Wandsworth recommends retaining half your garden, whereas Merton explicitly states you must not exceed 50% of any garden space. Also, Kensington and Chelsea limit the extension to half the garden and the depth of a single storey. 

There may also be conservation area restrictions. If you have trees in yours or your neighbours garden, you will have to consider the impact of digging into your garden. 

When planning your basement project, contact the local authorities to get up to date regulations. If you’re working with a build team, they will also be able to give you guidance and advice on how to build an underground room and what’s feasible. 

Planning the Layout

When designing the layout of your under garden basement, it’s important to maximise the space to make it worth the investment. This is where an architect can add value to the project. Here are some planning points to keep in mind:

  1. What shape and size do you want? Remember you will be restricted by planning regulations.
  2. How will the new room connect with your existing property?
  3. Where will services such as water, electric and waste be located? It’s useful to talk to a certified plumber and electrician to make sure your plans are feasible.
  4. Where will roof lights or light wells be positioned?
  5. What landscaping is needed to reposition the garden that will go back on top of it?

An important part of your layout plan is factoring in basement waterproofing. It’s best to have an expert put in a waterproofing course to make sure you have a guarantee. The last thing you want is a leak in your new space.

To make sure everything is taken into account professionally and to code, you will need to appoint a structural engineer to design a layout. A well thought out design will factor in the results of your planning survey, help protect your budget and keep the project on task

Blueprint for the construction
Image by Wokandapix from Pixabay

Interior Layout

Once you have a solid plan for the structural layout, you can turn your attention to the interior design. Here are some points to consider at this stage:

  • Will you incorporate spotlights, wall lights, or other sources of light into the design?
  • Where will doors and walls be positioned? Is this maximising space and what structural support will be needed?
  • If you need a staircase, where will this go?
  • If you’re installing a bathroom, where will plumbing be run?
  • Will you be installing heating or air conditioning?
  • What will the floor finish be?
  • How will you arrange the furniture?

It’s best to go through each of these points in advance. Without a proper plan, you might find you don’t have enough space for a bed or perhaps a bathroom isn’t a feasible option where you wanted it to go. Knowing in advance will help ensure your build team can run as smoothly as possible.

Uses for Your New Room

Building a basement under your garden is a great solution to many homeowner headaches. Whether you’d love more storage space or a home theatre, a basement is the perfect way to give that extra space you need. Here are some basement room ideas to get you started:

  • Kids need more space? Turn it into a playroom. 
  • Struggling to drag yourself to the gym? A home gym is another great option. 
  • Love family movie night? A decked-out cinema room will be a hit. 
  • Passionate about wines? Why not a wine cellar?
  • Need a little indulgence? A sauna or spa is will create a relaxing retreat. 
  • Love hosting friends? A bar or game room will keep them entertained!
  • In-laws constantly visiting? Think about a bedroom or granny flat. 

The possibilities are truly endless and can solve any of your current struggles. 

Underground living room with small windows, grey sectional sofa, brown wooden table

Under Garden Basement Ideas

Need some inspiration to design your basement? Here are some of the best under garden basement ideas to get your creative juices flowing.

Rustic and Cosy

By adding in wooden stairs and wood beams, the basement has a rustic charm and added character. 

Wooden beams and stairs in undergarden basement
Photo by Charles 🇵🇭 on Unsplash

An Entertainment Space

Who doesn’t love a bar in their own home? This space is perfect for entertaining friends and family. 

Undergarden entertainment room with tv
Photo by Aw Creative on Unsplash

A Home Spa

An easy way to make your new basement feel like a luxury spa is to add in some wood panelling. This gives a luxurious sauna feel that will melt away the stress of the day. 

A Playroom

When your kids need some extra space, a basement is a great idea. This adorable playroom is light, spacious and the perfect play for kids to make a mess. Just shut the door and visitors will never know!

A Stylish Bedroom

Show off the unique features of a basement by leaving some of the stone and brickwork bare. This industrial look is a unique style guests will be wowed by. 

Bedroom in basement with exposed walls
Photo by Aw Creative on Unsplash

Is an Under Garden Basement Right for You?

Do you feel you could get more from your garden and basement? Maybe it’s time to dig deeper and find out. Contact us to discuss your project.

East London Loft Conversion Ideas And Tips

If your house is in desperate need of more space or you’d love an extra bedroom, then extending into the loft can be the ideal solution. But before you start knocking through walls, there are several things to consider before getting started with a loft conversion in London. This guide will give you everything you need from the regulations you must meet to the best loft conversion ideas to help you get inspired. 

Where to Begin?

You probably have plenty of ideas about what to do with your loft space. But before undertaking  a loft conversion, you need to assess whether one is viable in the space you have! 

The most important things to know are:

  • Internal height – this needs to be 2.5m from ridge part to joist in the apex. 
  • Roof pitch – the higher the pitch the more head room you will have. 
  • Footprint – ideally, this should be 5.5m wide and 7.5m front to back. 

You also need to consider if your loft will allow for conversion. Traditional frames are best for converting but the rafters may need to be strengthened. However, trussed roofs will require more work to make them structurally sound. 

If your loft has a water tank in it, you may also need to consider moving the tank to accommodate the conversion. 

Furniture to use for your conversion
Image by tookapic from Pixabay

Biggest mistakes to avoid

Loft conversions come with many potential problems. Before you even get started, here are the biggest ones to avoid: 

  1. Forgetting about the stairs – finding staircase solution to a loft conversion can be tricky if there is limited space on your landing. There are also regulations to abide by so make sure you know these. 
  2. Forgetting about plumbing – this might need to be extended upon if you want to heat the room. 
  3. Assuming insulation is adequate – you may need to upgrade your insulation to make sure that at least the minimum standards are met before work can begin. 

Types of Loft Conversions

When you begin planning your loft conversion, you’ll need to decide which type is best for your house. Here are the different loft conversions available:

Dormer loft conversion

This is the most possible type of conversion. It creates a box shape from the slope of the existing roof which allows for windows. This leaves straight walls and ceilings, good light and ventilation, giving a light, airy space in an otherwise cramped attic. 

In addition, it usually falls under permitted development, is suitable for most homes and is relatively cheap. The downside is that they are not always the best to look at and can make your roof look a little clunky. 

Mansard loft conversion

Popular in terraced houses, these make use of the shared wall by raising the roof on that side and only having a slope on one side. This conversion is considered better looking, gives more headroom than other conversions and allows more light into the loft. 

But, this type of loft conversion will usually need planning permission, can take longer to complete and can be more expensive than other conversions.

If you have ideas for a bedroom loft conversion, this is usually the best option. 

Hip to gable loft conversion

This is best for end of terrace or detached homes. It works by straightening a sloping wall and can make a huge difference to the living space. It blends in with the existing home, can be combined with other extensions and is suitable for all homes including bungalows. 

It is not, however, suitable for mid-terrace homes is more expensive than dormer conversions. Plus, it can make the house unbalanced if next door doesn’t have one. 

Roof light loft conversion

This type of conversion doesn’t alter the space at all. Instead, windows are added and the floor reinforced. It’s much cheaper than full conversions, more likely to be approved and will get you plenty of storage if you use the eaves creatively. 

The downside is It does require a minimum head room in the centre, doesn’t give any extra space or may still require planning permission. 

How Much Does a Loft Conversion Cost?

Loft conversions can quickly become expensive when you don’t prepare a budget for the project and make a plan. However, when done professionally, loft conversions don’t have to cost a fortune. 

The cheapest and most straightforward loft conversion will be a room in roof conversion and will start around £15,000.  

A dormer will cost upwards of £20,000 but if you want to add an ensuite it will typically be £35-£40,000.

If you have to alter the roof structure it will cost upwards of £40,000.

These are just guideline figures, prices vary hugely depending on the work needed and level of finish you want. However, you’ll be able to get a quote for your project to get an idea of the cost for you. 

Conversion Regulations and Permissions

You don’t always need permission to have a loft conversion, but designs will need to adhere to certain parameters. If your property is listed or in a conservation area, then you may well need planning permission. 

You will also need a planning permission to extend the height of the roof or the shape of the roof. 

If you’re stressed about the planning permission, you have two main options to help you deal with the legal side:

Option 1: Hire an Architect or Designer

An architect or designer will deal with all the planning of the conversion and will be able to liaise with the planning permission authorities. They will also know exactly what is feasible and what isn’t when planning loft conversion layout ideas.

Image by aymane jdidi from Pixabay

Option 2: Hire a Build Company

What you’ll get from a design and build company is an all-inclusive package that will deal with all the planning permission and regulations that can come with a loft extension. They’ll also be able to take on the entire project which can save you a lot of stress. 

Choosing Who to Hire For Your Conversion

When it comes to choosing the right professionals to take on your loft conversion, it can feel a little overwhelming. With so many companies out there, it’s hard to know who to trust and the best people for the job. 

Here at Master Build Team, we make it our mission to help make the entire process of a loft conversion effortless and stress-free for you. With extensive experience in loft conversions, we know exactly what we’re doing and will walk you through every step of the process. 

Image by Borko Manigoda from Pixabay

Get Inspired: A Few Amazing Loft Conversions

If you’re raring to get started with your own loft conversion, here are some beautiful ideas to get you started.

Minimalist but Cosy

If you love a minimalistic, Scandinavian feel, you’ll love this loft conversion. 

simple and modern room with furniture
Photo by Julien Mussard on Unsplash

Industrial Brick

This light and spacious loft is the stuff of dreams.

warm and cozy leather slash brick combination
Photo by Derick McKinney on Unsplash

Functional and Organised

Make the most of every square inch of space with a wall of bookcases. 

a huge wall with books
Photo by Nathan Van Egmond on Unsplash

Bright and Architectural

Make a feature of your conversion with an architectural window that lets the light flood in. 

Photo by Kevin Wolf on Unsplash

A cosy Library

Need ideas for a small loft? Turn it into a cosy library you’ll never want to leave.

Small library in attic with lots of books
Photo by Jonathan Borba on Unsplash

Get Your Project Started Today

Interested to know if your loft conversion dreams can become a reality? Get in touch today to talk about your project. We’ll give you our expert advice on how we can help. 

Don’t fancy a loft? There are lots of other ways you can extend your space! 

Check out our post on Building An Under Garden Basement.