Oak Frame Extensions in Devon – Bespoke Oak Additions Built Properly
An oak frame extension is not something you “add on” at the end of a project.
It’s a structural part of your home that needs to be designed properly from the start — or it will never look or perform as it should.
At Rowan Oak Timber Framing, we design and build bespoke oak frame extensions across Devon as part of our wider oak framing services, working with homeowners and architects to create extensions that actually feel like they belong.
Why Choose an Oak Frame Extension?
Most extensions are built quickly using blockwork and hidden structure.
They do the job — but they rarely add character.
An oak frame extension gives you something different.
It allows you to:
• Create open, light-filled spaces
• Expose natural structure and materials
• Connect old and new parts of a building properly
• Add long-term value — not just square footage
If you're considering something smaller or separate from the main house, you might also want to look at oak frame garden rooms in Devon.
Types of Oak Frame Extensions
Every extension is bespoke, but common types include:
Kitchen Extensions
Open-plan kitchen and dining spaces with exposed oak structure.
Garden Room Extensions
Spaces that link the house to the garden with large glazed openings.
Side & Rear Extensions
Adding space without compromising the original building.
Oak Orangeries
High-end glazed extensions combining oak framing with natural light.
The key is proportion, roof design, and how the extension ties into the existing building — this is where most projects fail.
Many of the same design principles apply to structures like oak frame garages in Devon, where proportion and roof design are just as important.
Built Using Traditional Oak Joinery
We build using traditional mortise and tenon joinery used across all of our oak frame structures.
This is structural oak framing — not decorative timber.
What that means:
• Load-bearing oak frames
• Clean detailing without visible metalwork
• Long-term durability
• Proper craftsmanship you can actually see
Everything is prepared in the workshop before installation on site.
How the Process Works
Extensions are more involved than smaller structures — so clarity matters.
1. Initial discussion
You send drawings, ideas, or involve your architect.
2. Design coordination
We work with you (and your designer if involved) to ensure the oak frame works structurally and visually.
3. Quote
Clear pricing based on your design.
4. Workshop fabrication
Frame is cut, jointed, and prepared.
5. Installation
Delivered and erected on site as part of the wider build.
What Does an Oak Frame Extension Cost?
This is where expectations need to be realistic.
Oak frame extensions are a premium build method.
Typical oak frame costs:
• Small extension frame: £15,000 – £30,000
• Medium extension frame: £30,000 – £60,000
• Larger / complex frames: £60,000+
This typically covers the oak frame only, not:
Groundworks
Glazing
Roofing
Internal finishes
If you're comparing this to a basic block extension, you're comparing two completely different outcomes.
For smaller standalone builds, see typical pricing on our oak frame garden rooms in Devon page.
Planning Permission in Devon
Most oak frame extensions will require planning permission.
This depends on:
• Size and scale
• Impact on the existing building
• Listed status
• Conservation areas
We regularly work alongside homeowners and architects to ensure the oak frame fits within planning requirements.
Areas We Cover
We design and build oak frame extensions across:
• South Molton
• Barnstaple
• Bideford
• Tiverton
• Exeter
• North Devon & Mid Devon
We also take on selected projects in:
• Cornwall
• Somerset
Related Oak Frame Services
• Oak Frame Garden Rooms in Devon
• Oak Frame Garages in Devon
• Oak Frame Porches in Devon
• All Oak Framing Services
Start Your Oak Frame Extension Project
If you're serious about building an oak frame extension, the next step is simple.
👉 Request a quote or initial guidance
Send us:
• Architectural drawings (if available)
• A rough idea of your project
• Your location
We’ll come back to you with clear advice and a practical next step.