Loft conversion in London

How to gain space and add value to your property with a loft conversion in London. 

Adding a loft conversion to your property in London is a fantastic option to get more space. Adding extra bedrooms and an extra bathroom, for example, can increase the market value of your property substantially.

Like any other house or flat extensions in London, there are many different types of loft conversion to consider. The choice is largely dictated by the environment, the type of building, the neighbourhood and the council regulations.

At houseUP, we have worked in London with all the councils inside the M25 belt. We have forged strong, understanding relationships through our experience liaising with them, and with the planning and building regulation authorities across the whole of the Greater London area.



  • Meet in person to better understand what you want to achieve from your loft conversion.
  • View the loft to identify the physical challenges and plan a technical approach.
  • Capture the unsaid by collecting details, expressions, and moods for a unique design that reflects you and your lifestyle.
  • Explore the neighbourhood in order to view neighbouring loft conversions and understand the impact of your conversion as well as the context of your home.
  • Discuss in person your tastes and needs so we can: identify the priorities and the objectives of the loft conversion.

For a loft conversion in London, a site visit is crucial. Visiting in person allows us to gather visual information on the condition of the property. This is essential to identify issues, technical and regulatory constraints, and to become familiar with the neighbourhood. For example, it is easier to get permission for a loft conversion by, following the type of conversion adopted by other properties in your area.

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(design and build package only)

  • Translate the vision into something tangible by transferring to paper the ideas you have shared.
  • Define the constraints through creating a design proposal that is compliant with the council requirements.
  • Help you to understand the options and potential by identifying optimal ways to use your budget and achieve breathtaking results.
  • Connect the budget and design by creating a planning permission package that aligns with your budget.

Designs centred around light, head-height, lifestyle, taste and comfort yield the most rewarding results. Our aim is to establish and maintain an open communication channel in order to keep aligned, your vision and our understanding. We want to make sure that your priorities are taken care of. At times, we hope that you will trust in our expertise and heed suggestions that we know will improve the design and perhaps even be more cost effective.

2 6


(design and build package only)

  • Liaise with the planning authority and manage all meetings, meet requirements and provide feedback to all parties.
  • Prepare drawings and plans, complete all planning documents and related administration for submission.
  • File the approval application and submit the package for the planning decision.
  • Produce a pre-build package which includes building regulations and specifications, party wall agreements, leasehold management and more.

Managing a planning permission application is a careful balance between realising your desires, maximising the potential of your property and managing the planning authority requirements. It’s very often a matter of details, studying the history of past decisions, appointing the right consultants and communicating effectively with the planning authorities. We aim to be granted approval as quickly as possible, by avoiding filing a proposal that is too conservative and unrealistic.

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  • Define the construction costs and evaluate the basic construction work.
  • Estimate the options and optimise the choice of finishes and suppliers for the best result.
  • Communicate the quote clearly regarding what is included and what is not and what the impact of that might have.
  • Explain the process and the project program, define the communication channels, and agree on the decision flow.

Investing your money in a loft conversion can be a big decision. We want to make sure you feel you are in control of all the costs. Ultimately, you want all the price to be reasonable and reflect quality. houseUP will never quote unrealistically high or low prices, we will be transparent in any unavoidable additions, and we will always complete the project.

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  • Define a clear program in order to control the progress of the build and prevent issues.
  • Appoint experienced and trustworthy teams with specific expertise in loft conversions particular to the building, the local area, and the type of conversion.
  • Report and share information, give regular feedback and respond promptly to questions and requests.
  • Set up the communication channels: dashboard, live chat, photo and video sharing using the latest tech solutions.
  • Make timely decisions and follow a clear process for requests, approvals, and last-minute changes.

A loft conversion can cause some disruption to your daily routine. Working to high professional standards and delivering a high quality solution is paramount for us so we might suggest vacating your property for the duration of the project.

Information sharing and effective communication can make the process smoother and will keep you in control. English-speaking construction managers are always assigned sites and you have access to our dedicated communication channels for each loft conversion project.

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  • Finalise all the construction works for you to move in.
  • Compile a snagging list to check over all the small details.
  • Complete the snagging and sign off the project.

The very last few days of your project can feel the hardest sometimes. The wait for all the finer details to be retouched and taken care of can be excruciating. But it will feel worth it when at the handover your new, beautiful, comfortable living space is revealed in all its finished glory.

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    • Exceptional designing and planning that maximises the potential of your property with a loft conversion.
    • Planning permission for your loft conversion sorted.
    • Building regulations for your loft conversion approved, and the work started in a timely manner.
    • (in-house) Technical competence and experience from our in-house team of loft conversion professionals.
    • (in-house) All the documentation specific to your loft conversion project, including Health and Safety and planning conditions, prepared.
  • 02BUILD 
    • Specialist building contractor teams with extensive loft conversion experience.
    • A structural expert on-site to double-check current conditions of the house and to ensure safety and compliance.
    • The best tradespeople from electricians and plumbers to carpenters, decorators and more.
    • Access to exclusive kitchens and porcelain tiles directly from Italy at discounted prices.
    • Your vision to be realised with the quality of details meeting your expectations.
    • A dedicated project manager and structural engineer who specialises in loft conversions.
    • Prompt and professional handling of Health and Safety, party wall procedures, planning authorities, and sensitive approach to neighbours.
    • Efficient time management relating to orders, personnel on site, building regulations visits and other arrangements and appointments.
    • A clear decision-making process that maintains the running of the site.
    • Control of the houseUP dashboard, to monitor progress, budget consumption, see real- time photos and videos, and make comments.
    • Full involvement in the process, the schedule, and the choice of materials and finishes etc.
    • Access to a dedicated channel on the houseUP chat platform, for fast trackable decision- making and issue management.
    • A centralised, written record of all the conversations, questions, issues, and decisions in one place, that eliminates lengthy email thread discussions.


The dormer loft conversion is the most popular type of loft conversion in London. It is a box-shaped structure that replaces one of the slopes of a pitched roof. A dormer conversion creates a flat-roofed space that allows the installation of full-sized windows and the use of full-height furniture and other appliances. Dormer loft conversions are often allowed under permitted development. Councils in London have different rules on the size of dormer loft conversions.



A hip-to-gable loft conversion is often used for end-of-terrace or detached properties. The roof slope at the end of the terrace or of the detached house is replaced with a vertical brick wall. It is combined with a dormer conversion to maximise the space. Hip-to-gable loft conversions in London almost always require planning permission and are more expensive than simple dormer conversions. They are a very good option to increase the space gain, when possible.



A mansard loft conversion creates a flat roof space, but all four or two of the external walls are gently sloped, instead of being vertical, creating an additional storey. A mansard loft conversion is more aesthetically pleasant, because of the sloped walls, and minimises the visual impact from the street, which is important in densely built up areas. For example, all the buildings on Regent Street in London have mansard loft conversions, so that their street appearance is not impacted.



L-shaped loft conversions are specifically designed for L-shaped buildings. The shape essentially requires the construction of two dormers that need to be connected in a suitable way.

Roof light loft conversions allow natural light to enter, by installing roof lights in the sloped roof, on both sides.

Boarding and insulating lofts create a habitable space in a loft to be used as storage or simple guest rooms, at a minimum cost



The most frequent question we are asked about loft conversions is: how much does a loft conversion cost? The answer is not one for all. A standard loft conversion in London can have a different cost, depending on the context and the technical and the legal constraints.

Excluding finishes like windows, flooring, sanitaryware, etc., the average cost of a standard loft conversion in London is between £3,000 and £4,500 per sqm. At this price, the added value to your property is at least double per square metre.

View our full guide to learn more: How Much Does a Loft Conversion Cost?


Questions and answers

Collected questions that we often hear from you

  • How much will my refurbishment cost? 

    Every good building company will tell you that it is not possible to estimate the cost of refurbishment for a flat or a house before all the details have been defined. But we understand that it is important to have a reference figure before embarking in the process for budgeting purposes.

    We suggest a conservative estimate of £1,750 per square metre as the absolute minimum, and an average of between £2,000 and £3,500 per square metre.

    However, it’s important to keep in mind that there are details that can impact the cost significantly, the most costly being basement excavations or extensions of existing lower ground spaces; inclusion of very large or high spec glazing; very high energy performance materials.

    Additionally, some finishes can increase costs significantly, like paint, tiles or flooring, especially if the surfaces are very large,.

    In general, kitchens can be installed from as low as a few thousand pounds to hundreds of thousands, too.

  • 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.

  • 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.

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

    Yes we can. We partner with the best London architects 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.

  • 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.

  • 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.

  • 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.

  • 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.

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Get in touch with all your questions about loft conversions

Are you considering a loft conversion and need your questions answered? Do you have all the paperwork ready and want to get started? Get the ball rolling with the help of our loft conversion specialist team

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