House Extensions in London

Increase space and value of your house in London with a side or rear extension 

Extending your house is a great option to gain more space for a new room, to have a larger kitchen or more living space for the family. Any additional space in London is precious, and extending is a cost effective solution to improve your quality of life and increase the value of your property. That is why choosing the right house extension company is crucial for a final result in line with your expectations.

As space is so valuable in London, houseUP will help you optimise your plans. This way you will maximise the design and the space gain for you. Whether you want a larger kitchen, a play room for your children, a cosy living space for TV and video games, houseUP will be on your side to make the best choices for you and your family.

For your home extension, our teams will advise on the best solutions that are cost effective for your specific requirements and needs, with design and build or build services if you already have designs and plans from your chosen architect or designer.

FREE SITE VISIT

FREE SITE VISIT 

  • Meeting in person: understand what you want to achieve with your home extension in London
  • Understanding the challenges: assess the technical constraints and the budget to find the best and cost effective solutions
  • Viewing the place: see the space and understand your priorities and needs place
  • Discussing your taste and requirements: talk about your needs to focus on what is unique to you
  • Inspecting the building and the area: identify physical and regulation constraints to prevent issues and remove blockers
  • Capturing the unsaid: collect details, expressions, moods to design uniquely for you

A site visit is one of the most important steps for your construction projects. Every house and every person is different. Looking at your property and discussing your vision face to face is the best way to understand your vision, your priorities and your expectations.

Capturing the said and unsaid: what you really want to achieve

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VISION BRIEF AND BUDGETING

VISION BRIEF AND BUDGETING 

One of our partner architects with experience of house extensions in London in your area sits with you to understand your expectations, explain the cost options and translate your ideas in drawings.

(design and build package only)

  • Translating the vision: transfer on paper your ideas for your home extension in London
  • Overcoming the constraints: create a design that helps you visualise and evaluate
  • Understanding the options: define more than one option to choose the best house extension for your needs and your cost objectives
  • Optimising for the planning: use our planning experience to make the right choice for permitted development, planning permission, building regulations

Getting through all the legal aspects: quickly identify and resolve planning, party wall agreements, requests to council for access, traffic and more It is important to work together to make sure your vision for your renovation in London is transformed in the best design and plans. Priorities and requirements are different for each home extension. Getting them correctly is the secret to success. Sometimes a small inexpensive solution can save a lot of money and make you happier than complex and expensive specifications.

Translating the vision: how you achieve what you want with practical solutions

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DESIGN AND PLANNING

DESIGN AND PLANNING 

One of our partner architects specialised in home renovations in your area produces all the documentation and drawings to get you through all the regulation process

(design and build package only)

  • Liaising with the planning authority: find out details on permitted development, reports and planning requirements in your London council
  • Preparing drawings and plans: submit complete documentation to the planning authorities in your London council
  • Filing the application to approval: submit all the package for the planning process, be it planning permission or permitted development
  • Producing pre-build package:create all the drawings and plans for your home renovations, including building regs, construction drawings and specifications

Managing the design and planning process in London requires a deep understanding of your expectations and your budget requirements. Experience and previous relationship with the local area, council and planning authority are key to maximise the value of your house.

Optimising the planning process: exploit your property’s potential within the planning constraints

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FREE CONSTRUCTION ESTIMATION

FREE CONSTRUCTION ESTIMATION 

One of our estimation specialists produces an accurate quotation, including a break down of all the details and their cost

  • Defining the construction costs: evaluate the basic construction work for the extension
  • Estimating the options: optimise the choice of structural elements, layout, natural light elements
  • Detailing the specification: define the finishes and identify the suppliers for results that match your expectations
  • Explaining the quote: communicate clearly what is included or not and what are the most cost sensitive details that might impact the final cost
  • Communicating effectively: explain the process and the program for your house extension, set up easy-to-use communication channels, agree on the decision flow

Investing your money for a construction project is an important decision. Getting a quotation that is clear, transparent and comprehensible is the first step to a successful house extension. It’s You That is why understanding the quotation is paramount to make the best decision. A quote that is too high is a scam, a quote that is too low is even more dangerous.

Maximising the value for your money: gain space, light, quality of life and increase the value of your property.

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BUILD

BUILD 

The construction manager assigned to you organises the construction team, produces the time plan and manages the activities on site to build the extension

  • Creating the program: define a clear program to control the progress and prevent issues
  • Planning the work and executing on site: use experience, best practices, professional competence and the best teams on site
  • Reporting and sharing info: give regular feedback and respond promptly to questions and requests
  • Setting up communication channels: dashboard, live chat, photo and video sharing using the latest tech solutions
  • Making timely decisions: follow a clear process for requests, approvals, last minute changes and all decisions

Works to extend your house can cause disruption in your daily routine. Information sharing and effective communication are as important as the execution of the works. That is why you will have English speaking construction managers on your project and dedicated communication channels to avoid long and confusing email threads.

Delivering up to the expectations: produce top quality results through a hassle- and stress-free process.

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COMPLETION AND HANDOVER

COMPLETION AND HANDOVER 

Your construction project manager defines the snagging list, ensures all the tiny details are taken care of and reviews everything with you to get to a successful handover of your house extension

  • Completing the work: finalise all the construction works for you to move in
  • Checking all the details: compile a snagging list to sort out all the small details
  • Wrapping up all the final bits: complete the snagging and sign off the project

The very last few days at the end of your project can feel the hardest sometimes. You can’t wait to complete the works and start your new life and there are always the final details to smooth out. Finalising the last details can feel exhausting, after all the waiting and the disruption during the works, That is why we make sure to be there on your side, for any last minute request, question and fixing. Because seeing you happy is what motivates us everyday.

Taking care of all the final details: complete the snagging, provide all the certifications, warranties and documentation and sign off the project.

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HERE’S WHAT TO EXPECT WHEN WORKING WITH HOUSEUP

  • 01DESIGN (OPTIONAL) 
    • Work with an architect with specific experience in your London council
    • Use your London property’s potential in full with the best architects for planning applictions
    • Get planning and building regulations sorted in a smooth hassle-free process
    • Make the most of permitted development rules in your London council
    • (in-house) Optimise your structural design with our in-house engineers and partner architects
  • 02BUILD 
    • Get the best building contractor for your project in your London council
    • Have a structural expert on-site to check that foundations, beams and joists are installed correctly for your home extension
    • Use specialised tradespeople for your project, including electricians, plumbers, carpenters, decorators and more
    • Access exclusive kitchens and porcelain tiles directly from Italy at discounted prices
  • 03PROJECT MANAGEMENT 
    • Have an English speaking project manager with specific experience in London
    • Optimise orders, personnel on site, building regs visits and other arrangements
    • Ensure Health and Safety, party wall procedure, planning authorities, neighbours are managed promptly and professionally
    • Follow a clear decision making process to be on top of your home extension in real time
    • Have a project team who knows your area, council and building reg authorities
  • 04DIGITAL PLATFORM 
    • Take control of your construction projects in London
    • Follow progress even from your holidays abroad, through houseUP dashboard
    • Have access to a dedicated channel on houseUP communication platform, for fast trackable decision making and issue management
    • Keep a written record of all the conversations, questions, issues, decisions in one place, avoiding long email thread discussions
    • Understand budget consumption and priorities, remove impediments and blockers in real time
Ready to start?

Get a free site visit and quote for your house extensions in london.

Types of house extensions 

If you are considering how to build an extension to your home, it’s useful to think of all the options you have for the type of property. There are many options for your home extension, depending on your requirements on the size, the size of garden you want to leave untouched and obviously your target budget.

Types of house extensions

REAR EXTENSION 

It’s an extension at the back of a house, often in the garden. It’s a good option for detached and semi-detached houses. A terraced house extension at the rear of a property is also sometimes feasible.

REAR EXTENSION

SIDE RETURN EXTENSION 

It uses the narrow space at the side of a house, without using up garden space. It’s a great option for a ground floor extension, to implement a change of character on a ground floor without compromising the back garden area. This is an option for a semi-detached or detached house extension.

SIDE RETURN EXTENSION

WRAP AROUND EXTENSION 

It’s the combination of rear house extension and side extension. It can be a very big addition in size to the existing house. It’s feasible for a semi-detached or detached house extension.

WRAP AROUND EXTENSION

SINGLE STOREY EXTENSION 

It’s an extension of only one storey, like an extension at the rear of a terraced house to make a larger kitchen. It’s an excellent way to extend a terraced house, a semi-detached or detached house. With a single storey extension you can also add a sunroom or a conservatory, or add a play room or a new TV and sofa area to an existing living room.

SINGLE STOREY EXTENSION

DOUBLE STOREY EXTENSION 

It extends ground and first floor of a house. It allows to extend a ground room floor, most usually the kitchen, and to create additional space on the floor above, for example enlarging or creating a bedroom or a bathroom. Most commonly it is feasible as an extension of a semi-detached or detached house.

DOUBLE STOREY EXTENSION

LOFT AND BASEMENT CONVERSIONS 

Basement and loft conversions are also types of house extensions. You can check our dedicated pages to basement conversions and loft conversions for more details.

LOFT AND BASEMENT CONVERSIONS
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Average cost

Average cost 

The cost for a house extension in London can differ substantially depending on many factors. For example, the area and accessibility of the site is one factor. The nature of the soil can have an impact when new foundations are required. Party wall agreements and the number of involved parties can add to the construction cost.

To be able to budget for your house extension in London, though, it’s important to have an idea of the average costs.

The average cost of a standard house extension in London is between £1,500 and £3,000 per sqm, excluding finishes like windows, flooring, sanitaryware etc. At this price, the added value to your property is about double per square metre. For instance, in 2017 in the cheapest London borough the average property value was calculated as £4,000 per sqm.

House Extensions in London — FAQs

Questions and answers

Common questions about our house extensions in london service

  • Can I live at the property during the refurbishment? 

    We always recommend that you arrange for alternative accommodation during the project.

    Some of our clients choose to live at the property during the work, and, of course, we make that possible. However, please be advised that this arrangement comes with a significant increases in stress, cost and duration of the project.

  • Do I need planning permission for my refurbishment? 

    You won’t need planning permission for most refurbishment projects. If you are not changing the external appearance of your flat or your house, you won’t need planning permission. In many cases, you can make a loft conversion or a rear/side extension within permitted development rights. You can find all the details on which type of extensions are allowed under permitted development here.

    However, if you are planning to refurbish a listed building, you may need permission.

  • How long will my refurbishment take? 

    As per the duration of a project, it cannot be estimated without the full details. If you want to plan ahead, for alternative accommodation for example, we recommend at least:

    For smaller flat refurbishment, approximately 4 to 6 months. For house refurbishment, approximately 6 – 8 months These estimations relate to straightforward refurbishments like loft conversions or rear and side extensions. More complex work like basement excavations can only be estimated with more details, especially if access to the property is a consideration. Composition of the soil etc are also important factors.

  • I am buying a property, can you help me estimate how much the refurbishment would cost? 

    When you buy a new property, it is very likely that you’ll plan for a refurbishment. You can find some very good deals on the market, where you can buy a property for a good price when it needs some work done.

    By offering an estimation on work to be done, we can help you make the right decision and offer the right price for the potential property.

  • I have all the drawings ready with my architect, can you do the building works for me? 

    We certainly can! We work with the best architects in London through a tender process, for clients that choose to have the designs for their refurbishment made by an independent architect.

    We can provide quotes in our own very detailed format or in your architect’s preferred format.

  • I want to do everything with one company, can you do design and refurbishment for me? 

    Yes we can. We collaborate with top architects specialising in London house refurbishment and renovation planning which allows us to create designs that suit you and your needs. We will match you with architects who have specific experience in your area, share your vision and style for your refurbishment project.

    Doing the design and build with us gives you a view and control of the projected costs of your refurbishment from the very first day. You will be able to make well-informed choices for your design while understanding the cost implications and opting for the best solution for your investment.

    Check out our Design & Build page for more information.

  • What works make the biggest difference in the final cost of my refurbishment project? 

    Typically excavation to extend or create a basement under an existing property is one of the most expensive types of work in construction. The cost of finishes is another big factor in the final cost of a flat or house refurbishment.

150+Projects completed across London
10+Years delivering premium construction
2London offices Covent Garden & Hackney
A–ZFull service Design to completion

Why choose houseUP

01

Listed Buildings & Conservation Areas

We specialise in Grade I and Grade II listed buildings and conservation area projects across London — from Highgate to Chelsea. Our conservation architects understand the constraints and navigate them for you.

02

Transparent, Detailed Pricing

Every quote is itemised with material costs, labour, and timelines clearly set out. We list prices on our service pages because we believe you deserve to know what you're paying for.

03

One Team, Full Accountability

From first survey to final snagging, the same project manager oversees your build. No handoffs between contractors, no gaps in responsibility — just one point of contact throughout.

PROJECTS FEATURED IN:

Architects' JournalDezeenGrand DesignsReal HomesRIBA JournalThe World of InteriorsBest Houses

Reviews

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It was a pleasure working with Vincenzo, Gen and their team. They have such an eye for detail and we worked well as a team to produce a project the client was very happy with. They are professional. We would highly recommend.

Juliette ByrneArchitectural & Interior design

Working with HouseUP on two challenging Conservation Area / Grade I listed apartment renovations in London recently has been a true pleasure. Their availability, enthusiasm, very collaborative approach, skilled staff, and dedicated and diligent site management made a huge difference to bring these projects to successful completion. Addressing issues as they arise on historic apartment buildings, and calmly making sure they are successfully resolved, made a huge difference. We have no hesitation recommending HouseUP, warmly and highly.

LISA M.HIGHPOINT I

houseUP did a 4 month complete renovation of our flat in South Kensington. We were very pleased with their work. Vincenzo put together a great team led by a very capable site manager. They used high quality subcontractors for plumbing and electricity. They communicated well and in a timely manner with our project manager regarding issues and problems. They also worked well with the 3rd party MEP engineer and they handled minor issues with neighbours professionally. Works were completed on time (critical due to Covid restrictions) and on budget. All three tenders were similar in price, but houseUP’s was the most comprehensive/detailed which made it easy to evaluate.

HARALD E.SOUTH KENSINGTON

I used houseUP to renovate a flat in Shoreditch whilst I was overseas. I would certainly recommend them as, whilst expensive, they provide an excellent service and undertook to make the process as pain free as possible for me. They also worked well with my designer.

KATE V.SHOREDITCH

I would absolutely recommend Vincenzo and the houseUP team. They completed an 8 month full refurbishment/extension of our house at the end of 2019. They managed every detail of the project and did so with such a high level of care - often it felt like they were carrying out works to their own house! They were always available to discuss when needed and kept us in the loop as required (but didn't over burden us with issues they could easily resolve themselves). We are delighted with our new family home and I feel like the process was made so much less stressful by using houseUP.

SARAH GWILLESDEN

Vincenzo and the team were enthusiastic, creative and engaged. They brought the project in on budget and I'm happy to recommend them. Their approach of having in-house structural engineering really helped make savings by integrating the disciplines involved with design and construction.

ANDREW W.CHISWICK

A team, that is an absolute pleasure to deal with. Professional, helpful and responsive, with a direct approach to projects. Look forward to continue working together in the future.

VITA ARCHITECTUREChelsea

We highly recommend houseUP. As architects, it is always difficult to find good contractors and houseUP and the team are very professional and have great communication skills. Looking forward to working with them in the future.

WHITE RED ARCHITECTSChelsea

I hired houseUP after meeting with Vinz and the team - I found them down to earth, easy to deal with and very flexible and fair with me, unlike many other companies we asked to quote our project. They completed a double storey side extension and rear extension for me, plus complete renovation of my house. We have recently moved back into our house after completion of the project, and could not be more happy. Even if there are any issues at this stage, they are always on hand to help and put things right. It was daunting having to think about a company to do such major works for us, however Vinz was great all throughout the project and helped us achieve what we wanted. He was always available to speak to, and is knowledgeable and friendly. The transparency is something I do not think we could have got with most other companies, and for this I am grateful. Thank you guys!

JUNAID C.GANTS HILL

The houseUP team came to the rescue to renovate our penthouse in Shoreditch, London, after our first builders did a runner. They are great guys and trustworthy, they're real construction professionals and manage their subcontractors well to ensure a good quality of finish.

JAMIE AND LULUSHOREDITCH

Vincenzo, Mike and their teams of subcontractors are a breath of fresh air to the construction market. They are extremely well organised and professional, providing a high end service, with clear and constant communication to clients throughout their projects, no matter how big or small. Alison's rear extension was the first thing we completed with the houseUP team and we never stopped working together since our first construction project. We enjoy working with houseUP as the projects are realised with ease, on time and on budget. We highly recommend these guys to all of our clients for construction projects of all sizes in London and beyond!

MODEL PROJECTS (DESIGNERS)Chelsea
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