Thinking about a house extension in Bristol? Whether you’re dreaming of a light-filled kitchen extension or adding a two-storey side extension, one of the first things to understand is how much it will all cost.
As local architects working throughout Bristol and the surrounding areas, we help homeowners shape well-designed, practical spaces that enhance both daily living and long-term property value. While we don’t carry out the building work ourselves, we specialise in providing all the design, planning, and technical support you need to prepare your project for construction, as well as offering services to be on hand all the way through the build too.
From early sketches to full planning applications and building regulations drawings, we guide you through every step.
House Extension Costs in Bristol: What to Expect
Every project is different, and costs can vary depending on the size, complexity, and level of finish. Below is a breakdown of average build costs for different types of extensions in the Bristol area:
| Type of Extension | Estimated Cost per m² | Approximate Total Cost |
| Single-storey extension | £1,600 to £2,700 | £45,000 to £80,000+ |
| Two-storey extension | £2,000 to £2,800 | £70,000 to £120,000+ |
| Wraparound or L-shaped | £2,200 to £3,000+ | £90,000 to £160,000+ |
| Loft conversion (dormer) | £1,200 – £2,400 | £30,000 to £55,000 |
| Garage conversion | £800 – £1800 | £15,000 to £30,000 |
These figures reflect typical construction costs only. Design fees, planning application charges, structural engineering, and building regulations approvals are separate, and we can help you plan for those from the outset.
What’s Included in Our Architectural Services?
Our role as architects is to take your ideas and turn them into a workable, approved set of plans that builders can confidently price and construct. Our services often include:
- Initial consultation and advice on design possibilities
- Measured surveys of your existing home
- Sketch proposals and developed designs
- Planning drawings and application management
- Building regulations drawings and coordination with engineers
- Guidance on materials, layout, and space planning
- Support when choosing builders or reviewing quotes
We remain available throughout the project to answer queries, adapt plans if needed, and help ensure your build stays aligned with the original vision.
Why Appoint an Architect?
Architects offer much more than just drawings. We provide clarity, creative problem-solving, and impartial advice that helps you get the most from your space and your budget. Unlike design and build companies, we work entirely on your behalf and are not tied to specific contractors or products.
Benefits of using an architect for your extension include:
- Bespoke design tailored to your lifestyle and property
- Honest guidance on what is realistic and cost-effective
- Clear drawings that help avoid misinterpretation on site
- Freedom to compare builders before committing
- A stronger end result in terms of layout, lighting, and property value
In a city like Bristol, where homes range from Victorian terraces to modern eco-builds, working with an architect helps you navigate planning rules and create something that fits your home and neighbourhood.
Do You Need Planning Permission for an Extension in Bristol?
Not all extensions require full planning permission. Many smaller projects fall under permitted development rights, particularly for rear or side extensions. However, there are limits to what you can build without formal approval, and many areas of Bristol include conservation zones where additional restrictions apply.
We will assess your property and confirm whether planning permission is needed. If it is, we will prepare the full set of application drawings and handle the submission to Bristol City Council, along with any liaison or amendments needed during the process.
Building Regulations and Why They Matter
Regardless of planning rules, all extensions must comply with building regulations. These are national standards that cover safety, structure, energy efficiency, ventilation, and more.
We prepare building regulations drawings for your extension, which are used to gain approval from a local building control inspector or approved inspector. These drawings are also vital for your builder, as they include detailed technical information.
Building regulations approval ensures:
- Structural work is safe and properly supported
- Insulation meets energy efficiency requirements
- Fire safety, ventilation, and drainage are all in place
- Electrical and plumbing systems meet modern standards
- The build is signed off and certified once complete
What Can Affect the Cost of an Extension in Bristol?
Several factors can influence how much your extension ends up costing. These include:
Size and shape
Larger or unusually shaped extensions involve more materials and labour.
Materials and finishes
The choice of roof style, windows, and internal finishes can have a big impact on price.
Access to the site
If your property is hard to reach or has limited access, this can increase labour time and equipment costs.
Ground condition
Sloping land, poor soil, or drains in the way may require more groundwork or structural solutions.
Project specification
Adding a new kitchen, bathroom, or underfloor heating will increase internal fit-out costs.
Planning and location constraints
Homes in conservation areas or those that are listed may require additional design and approval work.
We work with you to create a design that delivers on your goals while remaining realistic and buildable within your chosen budget.
Our Process: How We Work
If you’re new to the extension process, here’s how we typically work with homeowners in Bristol:
1. Initial Consultation
We visit your home or meet online to discuss ideas, budget, and next steps.
2. Measured Survey and Design
We survey the property and prepare design options that reflect your lifestyle and preferences.
3. Planning Application (if required)
We prepare the necessary drawings and documents for submission and manage the process with Bristol City Council.
4. Building Regulations and Technical Design
We produce a detailed technical package for building control and for contractors to price and construct the work accurately.
5. Tender Support and Ongoing Advice
If needed, we can help you find reputable builders, compare quotes, and provide design support during construction.
Local Knowledge Across Bristol
We have extensive experience working on house extensions in many parts of Bristol, including Redland, Southville, Clifton, Bishopston, Totterdown, Westbury-on-Trym, Henleaze, St George, and surrounding areas. Whether you’re working with a character property in a conservation area or extending a more modern home, we understand the local character and the planning policies that shape development in the city.
0 comments
Write a comment