Drawing on the design mastery of nature, the Firma Shell is a beautifully organic structure that offers superior comfort while blending seamlessly with the landscape. The cleverly designed shell system ensures the Firma Shell is strong and steady while needing no internal support. Inside, this means freedom of space and uninterrupted views into the wilderness beyond, while reducing the footprint on your land.

Tims daughter enjoying the Firma Shell

“An amazing structure and space to be in – a modern take on how we remember camping.”

Tim Bullen
Firma Shell Owner, The Secret Campsite


With demand for glamping holidays reaching new heights and the range of accommodation options growing steadily with it, it’s critical to make the right choice now to ensure your future success. Knowing this, we design and create accommodation solutions that will help you stand out from the crowd and deliver a world-class experience for your guests.

Inspired by nature
Stand out from your competitors not the landscape. The beautiful, organic shape of the Firma Shell blends seamlessly with the environment ensuring it complements the view, rather than interrupting it.

Warm, dry and comfy
Superior water-proofing technology and a breathable, double layer skin combines with 100% British wool insulation to ensure things stay warm and toasty in winter and cool and dry in summer.

Maximum occupancy
Why choose form over function when you can have both? The Firma Shell’s unique design allows flexibility in sleeping arrangements. Create a spacious room for two or a cosy party for a family of five – with enough room left to swing a cat!

Unbeatable return
Combining a superior experience with a unique and memorable design, the Firma Shell commands premium per night prices and repeat bookings. This will see a well run unit return a profit in as little as 12 months, with an ROI of over 500%.


We believe there is nothing like the power of the outdoors to recharge and rejuvenate. We are woodland warriors passionate about sharing authentic experiences and enabling adventure that doesn’t cost the earth. Like our own well-being, our woodlands need to be protected and this ethos drives everything we do from strategy to installation.

Knowing where our materials come from ensures they are responsibly and locally sourced, 100% recyclable and of the highest quality.

Each structure is built bespoke, by experts in the UK, using a clever modular system that allows damage to be repaired rather than the entire structure needing to be replaced.

By delivering structures that are prefabricated and flat-packed we dramatically reduce their carbon footprint in production, transport and installation.

Having reduced our footprint as much as possible, we then partner with community projects to fund the planting of new trees where they’re needed most.


A design inspired by nature, the incredibly strong Firma Shell structure is built from timber laths woven into a diagonal lattice which, when curved and locked into place, form a rigid shell. This clever technique is ideally suited to the compact spaces of the Firma Shell, allowing you to maximise space on your site while leaving guests with uninterrupted views and an amazing aesthetic.

Using a technique usually reserved for large-scale architectural feats, this strong and stready structure is made using CNC plywood for superior strength and flexibility. Living up to it’s au naturel appearance, the timber we source is certified sustainable, UK-grown ash hardwood.

Outer Shell
Shelter from the elements comes in the form of a fully recyclable, marine grade reinforced canvas with triple stitched seems and ratchet tension webbing straps. This hard wearing, breathable shell also comes with a 10 year guarantee.

Skylights and Doors
A fully glazed, rigid polycarbonate front entrance wall with a counter weight assisted door and two flexible skylights flood the interior with natural light as well as offering unlimited star-gazing opportunities.

Made of corrosion resistant steel, the universal brackets are specifically designed for the unusual angles of the Firma Shell and will adapt and support the structure as the wood ages naturally, helping it age gracefully.

Our tried and tested exterior grade hardwood ply flooring comes as standard with the option to upgrade to the easy-clean marine grade teak look flooring.

Interior Liner
A high-quality recycled polyester lining comes standard with the option to upgrade to a luxurious 100% natural wool wadding to keep your Firma Shell especially warm and dry. Our wool comes from happy British sheep and we insist on suppliers who use organic dyes and non-polluting coatings.

Two year guarantee on the main structure

Full support and a comprehensive user guide

Proudly designed and manufactured in the UK

Insurability and safety checked



Our structures are made bespoke which means they are tailored to your site, needs and budget and you never pay for things you don’t need.

We start with the basics as standard:
Structural frame
Outer shell
Two skylights
A fully glazed front entrance
Hinged door
Standard high quality interior liner

From £13,995


Fancy a whacky colour? A practical floor covering that is easy to clean between guests? We then offer a range of extras that will enhance your glamping experience and help you make it your own. Pick and choose from the list below, or get in touch to discuss your ideas, we believe there is a clever design solution for every need!

Exterior and interior fabric colours and finishes

Number and placement of skylights

Micro wood-fired stove

Protective winter cover

Premium quilted 100% melton wool thermal lining

Multi-foil thermal insulation

Sustainable wool cushion and blanket pack

LED lighting kit

Rechargeable battery pack charging points

Expert installation assistance

International shipping

  • Exterior in a range of colours and finishes

  • Micro wood-fired stove with flue and heat proof backing

  • Multi-foil insulation

  • Custom branding

    Askersund Outdoor branding on their Tree Tent
  • Premium 100% melton wool lining in grey

  • Premium 100% melton wool lining in red

  • Custom made cushions for seats and beds

  • Number and placement of skylights

    Inside the Firma Shell
  • LED lighting kits

  • Expert installation assistance

Discover a new future for your site now

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