Unit 23, Battersea Business Centre
99-109 Lavender Hill
London SW11 5QL
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    0207 228 1324 Get in touch via phone
    [email protected] Get in touch via email
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    Loft Conversion Services in London

    A loft conversion is one of the most effective ways to add value, space, and comfort to your London home. By transforming an unused loft space into a bright, functional living area, you can unlock the full potential of your property – whether you’re looking to add a bedroom, home office, or private suite.

    At Armstrong Simmonds Architects, we specialise in bespoke loft conversions tailored to the unique architecture of London’s residential properties. As a RIBA Chartered architect studio, we guide you through the entire process; from feasibility and planning to design, detailing, and construction oversight.

    Loft Conversion Services in London

    Looking for Experienced Architects in London?

    Aside from providing you with a beautiful design, your architect needs to navigate complex
    planning and building laws that regulate the construction industry. Therefore, appointing a
    practice with the right amount of experience is the key to a smooth project delivery. Although
    not essential, appointing a RIBA chartered practice is also an important factor to consider.
    Being RIBA Chartered means that the practice must adhere to a code of conduct of
    professionalism and ethics which ensure quality control within the Architectural industry. The
    experience of the practice within London is another important factor to consider, particularly,
    as each borough has different modes of operation which can influence the design process.

    Whilst the National Planning Policy Framework (NPPF) provides the backbone for planning
    policy, each individual borough will have its own set of policy and guidance. A particular
    challenge within the borough of London is the planning process for basement design. For
    such a complex undertaking, stringent planning requirements must be met in the form of
    traffic reports, geology surveys and more. Another challenge is the added complexity of
    working with historic buildings. If your building is within a conservation area, a designated
    building of interest, or a listed building, any work to that building or surrounding area will be
    subject to strict requirements that are typically more rigorous than standard planning
    requirements. London Architects and designers must ensure their clients are advised
    appropriately on the process and that suitable consultants are appointed to conduct the
    necessary work.

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      What to Expect from Our Loft Conversion Service

      A successful loft conversion requires more than just floorplans and building work – it needs architectural thinking. We approach every project with a deep understanding of space, light, structure, and context.

      Our service includes:

      • A full measured survey of your existing property
      • Feasibility analysis and advice on planning permission
      • Concept design options tailored to your needs
      • 3D visualisations (optional) to help you imagine the space
      • Detailed architectural drawings and architectural services through Building Control
      • Coordination with structural engineers and consultants
      • On-site construction support to manage quality and progress

      We deliver loft conversions that look and feel like a natural extension of your home, not an afterthought.

      Our design team also takes into account the property’s original features, such as chimneys, dormer constraints, or roofline variations. We consider head height, fire regulations, stair placement, and daylight orientation, ensuring every detail is thought through from the start.

      Types of Loft Conversions We Offer

      Every home is different, and so is every loft. Our team of residential architects will advise you on the best solution for your property and ambitions.

      1. Dormer Loft Conversion

      The most popular option in London, a dormer adds a full-height extension to the rear roof slope, maximising internal space and headroom. Ideal for double bedrooms and en-suite bathrooms.

      2. L-Shaped Dormer

      A variation of the standard dormer, this layout is perfect for period terraced homes with rear outrigger roofs. It provides extra floor area and is particularly suited for large master suites or home offices.

      3. Mansard Conversion

      A more dramatic transformation that involves rebuilding the roof slope at a steeper angle. Mansards provide a more elegant design and are typically required in conservation areas, specific boroughs or properties with certain roof types.

      4. Hip-to-Gable Loft Conversion

      This method converts the sloping side roof (hip) into a vertical gable wall, expanding the loft floor plan. It’s commonly used in semi-detached or end-of-terrace homes.

      5. Velux Loft Conversion

      The most cost-effective option, a Velux (or rooflight) conversion keeps the existing roof structure intact while adding roof windows and insulation. Perfect for studies or guest bedrooms.

      If you’re unsure which option best suits your home, we’ll assess your property, planning context, and long-term needs during the design phase – ensuring you make the right decision.

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      Why Choose Us for Your Loft Conversion

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      Architect-Led Approach

      We bring creative solutions, planning expertise, and technical detailing to every project.

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      London-Specific Knowledge

      With over 15 years of experience across London boroughs, we understand planning policy, housing types, and build constraints.

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      Tailored Design

      No two lofts are alike. We craft designs that respect your home’s character and reflect your lifestyle.

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      Full-Service Delivery

      From design to construction oversight, we offer seamless service under one roof.

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      Proven Track Record

      Our portfolio includes dozens of loft conversions – from small attic studios to full-floor extensions.

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      Transparent Process

      We advise on the total loft conversion cost, including design, surveys, permissions, and build, so you have a clear picture from day one.

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      Our Loft Conversion Process

      We combine creative thinking with technical expertise to guide you through every stage of your project from concept to completion. The process typically includes the following key phases:

      1

      Concept

      Briefing & Survey
      Armstrong Simmonds Architects will work with you to develop a concept design, sketching layout options to explore the potential of the property. We will also carry out a full measured survey of the property and its surroundings, allowing us to produce an accurate set of drawings.
      2

      Planning

      Application & Scheme Design
      Following on from the briefing we will prepare a set of scale drawings reflecting the range of ideas discussed. We will prepare and submit the planning application, liaising with the council as needed throughout the process. Our extensive experience will help facilitate a smooth planning process.
      3

      Visualisation

      3D Modelling Services
      To help you visualise the space in three dimensions we can produce internal and / or external views of your project. This can also be a useful tool to demonstrate the merits of the scheme to planners.
      4

      Technical

      Building Control and Detailing
      We will produce detailed technical drawings including drainage and electrical layouts, consulting with you to ensure the design meets your needs. We will then submit to building control and manage the approval process. As part of our architectural services during this process we can assist you in appointing other consultants, for example the structural engineer or party wall surveyor.
      5

      Specification

      Interior Architecture and Schedules
      We offer interior architecture and design for a high spec finish. We can produce further detailed information integrating specialist glazing components, floor finishes, joinery and bespoke staircase design as required.
      6

      Interior Design

      Furniture, Fittings & Equipment
      We provide Interior design architecture services ourselves or through collaboration with other London based Interior Designers, who may also be appointed by the client.
      We are happy to specify FF&E (furniture, fittings and equipment) for the project, providing a complete “one-stop” shop for your development.
      7

      Tendering

      Prices and Builders
      We will help you make an informed choice on an appropriate contractor. We maintain a selective tender list of contractors especially in the local London area, who we have experience working with on site. We will prepare tender documentation and appraise their quotes.
      8

      On Site

      Contract Administration
      Armstrong Simmonds Architects facilitates the implementation of the design by administrating a contract between you and the contractor. Amongst a wide array of architectural services, this will include undertaking site visits to monitor the quality of construction and handle any on-site queries from the contractor.
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      FAQ

      Do I need planning permission for a loft conversion?
      Whether your loft falls under permitted development or householder development, we will guide you through the appropriate application process.
      Can I use my loft for a bedroom with an en-suite?
      Yes - many of our clients create new master suites with bespoke storage and bathrooms. We help configure the space to meet your needs.
      How long does a loft conversion take?
      Design and planning typically take 2-3 months. Construction lasts around 8-12 weeks, depending on the complexity, contractor and weather conditions. We help coordinate the timeline to fit around your family and builder availability.

      Customer
      reviews

      go to more reviews:
      Michael van Ree
      John and his team have been brilliant to work with for our full house renovation and extension in SW London. Our house is quite unique and that combined with it being in a conservation area we knew it wouldn't be a straight forward planning process - but Armstrong Simmonds did a fantastic job and helped us navigate us through every step. We couldn't be happier with the detailed design and outcome.
      Linda Roberts
      Architects Armstrong Simmonds were appointed by us to turn our concept of open plan living into reality, which they did with extraordinary vision and design flair. The AS team listened carefully to our ideas and transformed an ordinary detached house into a breathtakingly beautiful home that offered light, space and a lifestyle that exactly reflected our needs and requirements. AS worked closely with us and our builder, and their focus to detail in the design and build was impressive. This young architectural practice in our opinion, offers something more. They listen, understand and are unique in their ability to conceptualise, plan and build with imagination, whilst considering aesthetics and functionality. Linda and Allan Roberts ...>>
      Rowena Carter
      I cannot recommend Armstrong and Simmonds architects highly enough. Within minutes of John meeting us at our home he had understood our brief and was sharing a vision that ticked all of our boxes.We had met with other architects who did not inspire us and told us the shape we wanted for our extension would not be possible. John had excellent knowledge of the local planning rules, researched planning submissions in the immediate area and was confident that he would get our application through - and he did! During the detailed design process John and his team listened closely to how we wanted to use the space. He came up with many design features and solutions to save costs and keep our dream design within our budget. Throughout the process they delivered an innovative plan that felt personal to us in a professional and timely manner. We found John and his team to be responsive, helpful and caring. They went above and beyond to get our project over the line and I have no hesitation in recommending the firm to anyone looking at home extension/improvement. We would not look anywhere else for any future builds! ...>>
      Rebecca Wheelhouse
      We had a fantastic experience with John and the team at Armstrong Simmonds. We have a beautiful home and would happily use them for our next project.... hopefully even bigger next time! Flawless from beginning to end, I thoroughly recommend them.

      How to arrange our Loft Conversion Services in London

      Getting started with your loft conversion couldn’t be easier. Simply get in touch with our team, and we’ll walk you through every stage. We’re here to make the whole process clear, smooth and stress-free.

      Contact us today to arrange a consultation
      0207 228 1324 Get in touch via phone
      [email protected] Get in touch via email
      Armstrong Simmonds Architects Ltd
      Unit 23, Battersea Business Centre,
      99-109 Lavender Hill, London, SW11 5QL

      Get a free consultation today





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