Thinking of extending your home in Cardiff or the surrounding areas? Whether you're adding a new kitchen-diner, a luxurious home office, or creating an open-plan living space, one of the first questions you’ll ask is: how much do architects charge for extensions in Cardiff?
At Fortis Estate Agents, we work closely with homeowners looking to add space, style, and value to their homes. We understand that planning a home extension can be both exciting and daunting, and having the right guidance at the beginning of your journey can make all the difference.
In this guide, we’ll break down:
When and why to hire an architect
How architects in Cardiff structure their fees
What’s typically included in architect services
Tips for choosing the right professional for your project
Let’s dive in.
If your project is relatively small or falls within permitted development rights, you might be tempted to skip using an architect and go straight to a builder. While that might seem like a cost-saving shortcut, it often proves more expensive in the long run — especially for higher-value homes where design precision and planning are critical.
Hiring an architect can offer several advantages:
Maximise the value of your investment – An architect can help you design a space that adds both functionality and market appeal, potentially boosting your property value far beyond the build cost.
Avoid costly mistakes – Poorly thought-out designs can lead to structural issues, planning rejections, or expensive redesigns mid-build.
Professional planning and design – Architects bring creative ideas you may not have considered, helping you make better use of light, space, and layout.
Clarity for builders – Detailed architectural drawings help builders quote more accurately and reduce miscommunication on-site.
If you’re working with properties in Cardiff valued over £500,000, especially in areas like Llandaff, Cyncoed, Pontcanna, or Penarth, the design quality and finish can significantly impact resale value. A well-executed extension could be the difference between achieving market average and commanding a premium price.
Architect fees can vary depending on:
The complexity and size of your extension
The scope of services you require
How the architect structures their fees
Your postcode — for example, architects in Cardiff and the Vale of Glamorgan may charge more than rural areas
Here’s a breakdown of common pricing structures:
This is one of the most common fee models. Architects typically charge between 5% and 15% of the total build cost. For a high-spec extension costing £80,000–£120,000, fees may range from £4,000 to £18,000, depending on the level of involvement.
Some architects offer a fixed price for defined stages of the project. For example:
Design and planning: £2,500–£4,000
Building regulations: £1,000–£2,000
Project management: additional £2,000–£5,000
For smaller consultations or bespoke input, architects may charge an hourly rate. In Cardiff, this can range from £70 to £150 per hour.
Architects in Cardiff typically provide services in stages — you can hire them for the entire project or select the stages you need.
Here’s what may be included in your quote:
Initial consultation and concept design
Measured survey and existing layout drawings
Proposed architectural drawings
Planning application support
Building regulations and technical drawings
Liaison with planning officers or structural engineers
Support during the construction phase
Some architects also offer interior layout planning, 3D visualisations, and project management services — ideal for premium home extensions.
It’s essential to read the quote carefully. A lower initial fee may exclude key services like planning submission fees, structural calculations, or site visits, which can be added later as extras.
When choosing an architect for your home in Cardiff or South Wales, particularly if you're working on a high-value property, make sure you:
Ask for a full breakdown of services and costs
Check if they are RIBA-registered (Royal Institute of British Architects)
Review their previous work on similar homes or extension types
Get clarity on timelines and communication processes
Ensure they understand Cardiff Council’s planning regulations, especially in conservation areas like Cathays Park or Roath Mill Gardens
A reputable architect will be transparent about costs, offer references, and be open to collaboration with your builder or contractor.
If you’re considering whether to extend or sell your current home and move into a larger, more luxurious property, Fortis Estate Agents can help you weigh the pros and cons.
We have extensive experience in Cardiff’s premium property market, specialising in homes desirable locations such as:
Penarth & Sully
Radyr & Lisvane
Cowbridge & the Vale of Glamorgan
Roath Park & Llandaff
Take a look at our current listings or speak with one of our property experts about the best options for your next move.
Using an architect for your home extension in Cardiff may seem like a significant investment, but it can deliver long-term value by enhancing your living space, maximising your home’s resale potential, and helping you avoid costly mistakes.
Whether you’re looking to upgrade your current home or move into something new, Fortis is here to support your property journey every step of the way.
📞 Contact Fortis today on 029 2056 1111 or email hello@fortis.homes
🌐 Or browse premium listings at https://fortis.homes
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