House Extensions

House Extensions Company in London: We'll help create your dream bedroom, bathroom or kitchen

Is your home space too cramped? Do you have a growing family and need an additional room or two? Maybe your older family members need to move in for your love and support?

Bischell’s team of architects, builders and engineers have helped many singles, couples and families achieve optimum living space with innovative interior and exterior design. We specialise in the following types of home extensions:

  • Bedrooms
  • Bathrooms
  • Dining rooms
  • Kitchens
  • Gyms and fitness areas
  • New conservatories
  • Additional toilets and shower rooms
  • Basement, cellar and loft conversions

No matter what you’re looking for, we’ll make sure that every minute detail of your new living space looks just as good as you’ve always imagined.

Whether you need construction or design and build, we’ll bring your house extension to life with the finest design and craftsmanship. Most importantly, we’ll ensure your ideas achieve their full potential.

A team of construction experts for your house extension

A house extension can be a big undertaking, which is why you’ll have the full Bischell construction team working to ensure an accurate and hassle-free build.

  • Bischell builders and roofers to construct your home extension with millimetre accuracy
  • Bischell electricians, plasterers, plumbers, glazers, decorators and fitters to capture the vision of your design with fine craftsmanship
  • Use your own architect or hire a Bischell project manager

With our infrastructure, we can also handle anything from small porches through to multi-storey extensions, which require the pinnacle of engineering that Bischell possess.

4 guarantees with our Flawless Delivery™ promise:

  • On-budget – The cost, based on the original brief, is contractually fixed
  • On-time – Finished on time, but if not, we pay you for every day it goes over
  • Defect-free – You only sign the project off when everything is perfect
  • 12 month warranty – If there are any problems, we’ll fix them for good

You expect first-class support – with Bischell you’ll receive it

We’ll communicate regularly to keep you up to date, with a direct line of contact for quick answers to any of your questions. Even better, you’ll be able to view project updates, progress and scheduling via your very own online project management portal.

What you can expect in your new house extension:

We’ll make sure that your house extension captures every detail of your plans to give you the dream result you’ve hoped for. We ensure that everything, from the first brick laid, to the last lick of paint, is applied with meticulous detail for an immaculate finish.

Plus, it’s not just about the final result, but the service as well. With a fully organised and fully accredited team on hand, we can ensure a smooth and efficient schedule so you can spend more time enjoying your new extension take shape.

Designing your perfect house extension

The only way you’re going to be delighted with your new house extension is if every detail is just perfect.

That’s why we follow your every word to capture even the smallest touches which can add up to make a real difference.

You’ll have the entire Bischell architectural team on your side, including architects, engineers and interior designers, to design a beautiful extension which maximises space, light, practicalities, functionality and value.

We’ll also help you choose the sizes, shapes, fixtures and themes you love the most, with concepts and 3D models also show you exactly how your new house extension will look before the first brick is even laid. See our gallery to review 3D samples.

4 guarantees with our Flawless Delivery™ promise:

  • On-budget – The cost is fixed, and it won’t change based on the original brief
  • On-time – Finished right on time, but if not, we pay you for every day it goes over
  • Defect-free – You only sign the project off when everything is perfect
  • 12 month warranty – If there are any problems, we’ll fix them for good

You can leave any planning permission or building regulations to us

We can check if your house extension falls under ‘permitted development’ which requires no planning permission. If not, we can liaise with your local council to obtain planning permission for you.

What you can expect from your house extension design:

A house extension should transform your home. The extra space can open up whole new rooms and living spaces that are beautifully designed to make them a joy to experience time and time again.

Outside, your extension blends superbly with your existing home. Inside, you can step into spacious, fresh and modern living areas which are meticulously designed to your exact tastes.

Simply put, we won’t stop until you’re left with plans which give you the right rooms, the right sizes and the right designs which are all perfect down to the last detail.

Choose us to make your house extension plans a reality.

The result?

A beautiful house extension which ticks every box.

Click here or call 020 8964 1814 for a free, no-obligation consultation where we’ll show you what we can do for your house extension in London.

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If you have a project you'd like to discuss, please get in touch. There's no obligation. Just give us a call or if you'd rather email, simply complete the form.



Why Bischell?

An optional industry-leading lifetime guarantee

We'll give you a fixed price which won't budge

A guaranteed completion date or we pay you

We won’t stop until your project is 100% defect free

Bischell 360 Support360° Support® for peace of mind every step of the way



  • We contracted Bischell for our fairly large house renovation and I can honestly say that while their prices were comparatively higher, the service and professionalism is unparalleled. We had used a cheaper alternative on our first home and that turned...

    Benjamin Friedmann Vice President at WorldOne

  • Just wanted to thank all the team at Bischell for the incredible amount of hard work over the past 4 months. It's been quite a journey but I'm happy to be at the end of it now. Sorry to see...

    Dave Jones West Finchley – Barnet

  • They have a solid track record on projects we've worked on. Their dedication to a project is second to none. A real flagship example of how it should be done....

    Jonathon Cray Property developer

Some of our clients

Bischell 360 Support

Based around six key pledges, it’s our promise to you to ensure rock-solid reliability and a seamless, hassle-free project