RENOVATION + EXTENSION
A brief guide to refurbishing / extending your home
We specialise in transforming existing homes through thoughtful extensions and refurbishments. With a strong track record of successful projects for private clients, we take pride in listening carefully to your needs and bringing your vision to life with care and precision.
Extending your home is more than just gaining extra space — it’s an opportunity to reshape your living environment to better reflect your lifestyle, improve comfort and energy efficiency, and express your personal taste. Great design plays a vital role in making this a reality, and an experienced architect is essential to ensuring your home feels both unique and carefully considered.
If you’re thinking about making changes to your home, we’re always happy to explore the possibilities with you — please feel free to get in touch.
While every project is unique in style and scale, the process we follow is consistent and clear. We work in line with the RIBA (Royal Institute of British Architects) stages of work, and below we’ve outlined what typically happens at each stage so you know what to expect throughout your project journey.
01
Exploring Ideas
Before we begin designing, it’s important to understand exactly what you hope to achieve with your home. In our initial meeting, we take the time to talk through your goals, needs, and lifestyle so we can shape a clear brief. This conversation includes everything from practical requirements to early design ideas you might already have. We’ll suggest ways to incorporate sustainability and show you precedent projects that could offer inspiration, alongside a curated moodboard to help capture the overall tone of the project.
At this stage, we also introduce an early discussion about budget. While it may feel too soon, having a realistic understanding of costs is essential to guiding the design in the right direction. We provide informal advice on what similar work might cost so you can move forward with clarity.
By the end of this stage, you’ll have a well-defined written brief, a collection of visual references to anchor the design vision, and an initial working budget to guide the next steps.
02
Conversations & Sketches
Once the brief is agreed, we begin exploring how your ideas might take shape through sketch design. Every home presents its own set of opportunities and constraints, and we’ll guide you through the possibilities to find the most effective solution. We develop simple sketch plans and basic models to communicate the ideas, giving you a clear sense of how the design could work.
We also revisit the budget in more detail, considering all aspects — not just the building works, but also finishes, fittings, and furnishings. We believe in presenting a realistic picture of total costs, helping you avoid unexpected expenses later on. It’s common to hear rough ‘rules of thumb’ for construction pricing, but in our experience, costs can vary greatly depending on design choices, specifications, and the existing condition of your home. At this stage, our goal is to help you understand what’s possible and what it might cost in real terms.
03
Developing the Design
With your agreement on the sketch design and outline budget, we move forward to develop the proposals in more detail. We produce architectural drawings, explore models and collages, and begin to bring the spaces to life. To help you fully understand how your home will feel, we use digital tools to create visualisations, including animations and virtual 3D models that you can explore on a phone or tablet.
These visual techniques are more than just presentation tools — they help uncover opportunities within the design, like a better view from a repositioned window, a perfect spot for a window seat, or thoughtful storage tucked into unused corners.
At this point, we also bring in an independent Quantity Surveyor to create a detailed cost plan. This gives us an up-to-date picture of how your design aligns with current market rates. While our early-stage estimates are often very close, this cost plan provides a helpful cross-check and, if needed, allows us to make adjustments to keep things on track before applying for permissions or beginning construction.
Planning Permission
At the end of this stage we prepare and submit the planning application. The planning system can be complex, especially with the growing number of permission types and specific conditions relating to different property types, areas, and local authority policies.
We have extensive experience working across various planning contexts, including conservation areas and listed buildings. We’ll advise you on the best route forward, whether through a full planning application or permitted development, and ensure the design responds to your home’s specific setting. We’ll then handle the submission, liaise with the council, and guide the application through to decision.
04
Detailed Design & Tender
At this stage, we move into the technical side of the design. This is where the finer details are resolved — from the exact positioning of windows to the precise height of shelves or width of joinery. It’s a stage that can often be overlooked, but it’s critical to the success of the finished project. Careful detailing is what elevates a project from simply functional to truly refined.
We produce a full set of construction drawings and specifications that can be priced accurately by contractors. We then invite a selection of trusted builders to tender for the work. These are contractors we know to be reliable and skilled, and who have expressed interest in your specific project. Once prices are returned, we review the submissions with you in detail, clarify any queries, and support you in selecting the right team for the build.
Building Control - At the end of this stage, we will submit the necessary information for Building Regulations approval. This process ensures that the proposed work complies with national standards for safety, structure, insulation, drainage, and more.
We handle the entire submission on your behalf and liaise directly with Building Control to address any queries. Throughout the construction phase, we also coordinate with the contractor to make sure all required inspections take place at the right times, helping to ensure the work is fully compliant and properly certified.
05
Construction
When construction begins, we act as your contract administrator — overseeing the project, protecting your interests, and ensuring the build matches the agreed design. We typically recommend using a traditional building contract, which provides a clear legal framework and allows us to manage the work, timeline, and payments.
We visit the site regularly — weekly or fortnightly, depending on the stage — to inspect progress and quality. We also issue regular reports, highlight any decisions that need to be made, and make sure you stay fully informed. A key part of our role is certifying monthly payments to the contractor, ensuring you only pay for work completed to a satisfactory standard. The contract also includes a completion date and penalties for delays, helping to keep the project moving efficiently.
06
Completion and Aftercare
As your project nears completion, we stay closely involved to ensure the final details are properly finished. We work with the contractor to identify and resolve any snags or incomplete elements, and we don’t consider the job done until everything is to the standard we agreed.
At handover, you’ll receive a comprehensive pack with information on any systems installed, along with notes on maintenance and materials for future reference. But our involvement doesn’t end there. Building contracts include a ‘defects period’ — usually six to twelve months — during which a portion of the contractor’s payment is held back. This ensures that any issues that arise post-completion are addressed properly.
We continue to support you during this time, coordinating any necessary follow-up work, and issuing the final completion certificate once everything has been resolved. Your project ends not just with a finished space, but with the confidence that it has been thoughtfully and professionally delivered from start to finish.
Additional Information
Budget
Budgets vary on refurbishment / extension projects depending on the project size, the level of specification desired and also the extent of any repair work required to the existing house. A simple kitchen extension will cost considerably less then a full house restoration and upgrade. We can provide initial cost estimates in the early stages to develop budgets and then suggest the designs are independently costed at stage 03 to clarify assumptions. Construction costs have fluctuated significantly over recent years, and while the market is more stable now we still find it useful to confirm our estimates with external advice.
On residential projects we often help source some of the large elements - ie the glazing or specialist finishes as buying these directly rather than through a contractor can save you money and give you more choice. We expect to do this and allow for it in any proposed fe
Fees
Projects involving existing homes can be time-intensive, and we believe in producing fully detailed information to ensure accurate pricing, smooth construction, and a well-managed process from start to finish. To keep things clear and manageable, we typically structure our fees across three stages.
Stages 01 and 02 – Brief and Sketch Design
We understand that deciding to renovate or extend your home is a significant step, and it can be helpful to explore your options before committing to a full architectural service. That’s why we offer an initial package for a fixed fee of £800. This includes early sketch designs, a written project brief, and an outline budget. It’s a chance to develop ideas, clarify what’s possible, and get a feel for how we work — all without a large upfront commitment.
Stages 03 and 04 – Developed Design, Planning, Detailed Design, and Tender
Once you’re ready to move forward, we charge a fee of 8% of the defined project budget. This figure is based on the total cost of all building works and materials (excluding VAT and other professional fees). Charging a percentage allows our fee to scale with the size and complexity of the project — offering flexibility without the need for constant renegotiation.
The final payment at this stage is adjusted to reflect the confirmed construction cost before work begins on site, ensuring everything remains fair and transparent.
Stages 05 and 06 – Construction and Completion
During the construction phase, we charge a weekly fixed fee to cover our ongoing involvement on site. This includes regular visits, managing progress, resolving day-to-day issues, and issuing payment certificates to keep the contract running smoothly. This structure ensures you have continuous support through to completion without hidden or unexpected costs.
Sustainability
We are acutely aware of the contributing factors of both building construction and building energy consumption to Global Warming and other environmental concerns. On each of our projects we assess sustainability from the out-set, and develop clear, achievable strategies to minimise environmental impact.
Our aspiration is always to design to the efficiency standards commensurate with a low carbon future using a combination of passive and active design methods. This may include proposing insulation levels above minimum requirements, the careful consideration of details to eliminate ‘cold bridges’ and exploring efficient services including the use of heat-pumps where appropriate and low energy lighting.
Where new construction is proposed, materials will be specified from certified sustainable sources. All new structure will be formed from materials chosen to provide minimum ‘A’ ratings as listed in the BRE’s Green Guide to Specification. Where possible the proposed design will use reclaimed materials, or materials with low levels of embodied carbon. The use of materials with high levels of embodied carbon such as concrete or insulations formed from petrochemicals will be avoided where possible.
Our designs always consider end of life considerations, with an emphasis on designing and specifying works that can either be re-used of safely disposed of at end of life. This in turn encourages a use of natural and regenerative materials wherever possible.
Wellness
The use of natural based materials is also proven to benefit building occupants due to their lower levels of toxins such as VOCs that can be harmful both during and after use. Recent developments in natural construction materials have led to the development of high performance products that avoid these toxins and we advocate their use wherever appropriate.
Further design considerations including the provision of suitable daylighting, considered lighting, considered acoustics and reverberation, interaction with internal and external biophilia and an encouragement of bio-diversity are also recognised as contributing positively to occupiers health and well-being. We explore these considerations throughout our design work to ensure our projects provide a comfortable and healthy environment for all building users.
Consultants
You’ll likely need to appoint a structural engineer and a party wall surveyor depending on the extent of works. We can recommend people for these roles and help you get them appointed. Typically, an engineers fee would be up to £1-2,500 and a party-wall surveyor to be about £1,500 assuming only two neighbours need to be consulted. As mentioned above we would recommend a quantity surveyor provide an initial cost plan at stage 03 - this would normally incur a fee of around £500.
Building Control
You will need to either appoint the local council or an approved inspector to inspect and sign off the works in relation to Building Regulations. Approved Inspectors cost a bit more but are generally much easier to work with than the council - expect a fee of around £2,000.
Following the introduction of the Building Safety Act in 2023 it is now also required for you to appoint a suitably qualified Principal Designer to manage the building control application. MWA can act as Principal Designer and will include for this in any quoted fees.
Contractors
We have a few contractors who we’ve worked with successfully in the past and would be keen to workwith again. We also have a longer list of recommended names form other professionals that we are keento work with. We would suggest tendering to 3 or 4 contractors to get a good price. Costs can vary quite considerably depending on who is busy etc. so going to a few with a fully detailed design gives you the best option for getting good value.
CDM Regulations
The Construction (Design and Management) Regulations 2015 will apply to the proposed works to encourage the use of best practice health and safety procedures. Clients have specific duties they are required to perform under this act. MWA will advise you of these duties and act as Principal Designer as defined by the regulations.