Celsium Jonas Classic - Premium Outdoor sauna - 4-6 Person

The Celsium Jonas is a premium 4-6 person outdoor sauna, handcrafted in Lithuania, with a square, contemporary form and a floor-to-ceiling glass front that opens the whole cabin to the garden.

Celsium has been building saunas since 1994, and the Jonas shows it. Clean Scandinavian lines, a design registered with the European Union Intellectual Property Office (EUIPO), and a precision-fit timber structure that looks as considered from the lawn as it feels from the bench. Celsium saunas can be personalised to suit the style of your space - with the beautiful vertically slatted exterior timber specced in Scandinavian spruce, Thermo pine, Thermo Radiata pine or go jet black with the charred Japanese "Shou Sugi Ban" which naturally colours and protects the timber. You can also select to have the glass door entry door to left or right of the cabin to suit your garden arrangement.

Every Celsium sauna is built in-house by master craftsmen, using carefully selected, premium, sustainably sourced Nordic timber. That gives the maker full control over quality, materials and craftsmanship from start to finish. In Celsium’s own words: “We don’t just assemble – we build saunas with precision, passion, and purpose.”

Step through the full-height glass door and the cabin is warm, quiet and bright. Two-tier benches, built to Finnish sauna proportions, give you even heat and warm feet, with room for four to sit or one to stretch out along the upper bench. Dimmable LED lighting beneath the benches turns dusk into the best part of the session.

Walls, ceiling and floor are fully insulated with PIR panels, so the Jonas holds its heat through a British winter. You can choose the spec of the interior timber with a finish in aspen, black alder or thermo aspen. The EPDM roof is built to shed the weather season after season.

Choose your heat. Pair the Jonas with an electric stove for easy, controllable sessions, or a wood-fired stove for the crackle, the scent and the full ritual. Our range covers both, with pricing varying by heater.

The glass. The grain. The heat.

Key Features

• Premium contemporary sauna - Fully customisable to meet your needs and aesthetic.
• Handcrafted in Lithuania by Celsium, building saunas since 1994
• Built in-house by master craftsmen from carefully selected, premium, sustainably sourced Nordic timber
• Floor-to-ceiling panoramic front in 8mm tempered glass, with a full-height glass door - with customisable location to suit your setting (left or right).
• Contemporary square design with clean Scandinavian lines - design is patented with the European Union Intellectual Property Office (EUIPO).
• Two-tier benches built to Finnish sauna proportions: even heat, warm feet.
• Seats 4-6 with space to relax. Benches are full-length allowing for reclined and laying postures. 
• Integrated PIR insulation applied to walls, ceiling and floor for efficient heating and use in all weathers. 
• Configurable personalised specification: Exterior wood type in - Scandinavian spruce, Shou Sugi Ban (Traditional Japanese burning technique) or thermo pine; 
• Configurable personalised specification: Interior wood type in - Nordic spruce, Aspen, Black alder, Thermo aspen or Thermo Pine. 
• Dimmable under-bench LED lighting as standard
• EPDM all weather rubber roof
• Tinted glass options: clear, bronze, grey, Planibel black or mirror
• Choose your heater from a curated range of industry leading electric and wood-fired stoves (price varies by heater)
• 5-year structural warranty from Celsium
• Expert UK advice from the Origin State team before and after you buy

Specifications

• Capacity: 4-6 person
• Dimensions: 2.16m (w) x 2.16m (d) x 2.45m (h)
• Footprint for base: approx. 2.2m × 2.2m
  
• Weight: 750kg
• Usable bench length: 1.8m wide, two-tier benches.
• Bench depth: Top bench 58cm deep, Lower bench 52cm deep. 
• Exterior: Scandinavian spruce (standard), Shou Sugi Ban or thermo pine
• Interior: Aspen, black alder or thermo aspen
• Insulation: PIR panels in walls, ceiling and floor
• Roof: EPDM rubber
• Glazing: 8mm tempered safety glass, full-height front and door
• Door: Full-height glass, hinged left or right
• Lighting: Dimmable LED under the benches
• Heater: Electric or wood-fired, selected from our range; price varies by heater
• Warranty: 5 years structure, 2 years other parts (heater to manufacturer’s terms)
• Assembly: Flat-pack or fully assembled

Installation

Deliver Flat Pack: The Jonas is delivered on a pallet, as a precision-fit flat-pack kit. Pallets are heavy, so a forklift or HIAB will be provided for unloading. You may assemble it yourself. Or our professional installation team can take care of the full assembly for you for an additional installation fee. 

Alternatively you can select: Deliver Fully Assembled (+ £1500). Your sauna will be delivered as a complete assembled unit, pre-built in the Celsium workshop. A forklift or crane will be required to unload your sauna and lower it into it's final in use position in your garden/land. You can arrange your own local lifting service. Or our team can coordinate it on your behalf for an additional service fee, depending on access conditions.

Installation base requirements: a solid, level base of at least 2.2m × 2.2m, such as concrete or a suitably reinforced platform, rated for the weight of the cabin and its occupants. A level base keeps the glass door aligned and the structure performing as designed.

Electrical connection: Electric heaters must be connected by a qualified electrician in accordance with UK regulations, on a dedicated circuit with an isolator and RCD protection. Wood-fired stoves are fitted with a chimney, which should be installed correctly and safely. Heater manuals are available in advance, and we’re happy to talk through what’s needed.

Care: Like any quality timber building, the exterior benefits from being inspected and re-treated about once a year to keep it looking its best.

Delivery timeline: Celsium Saunas are made to order this takes time, but is well worth the wait for bespoke sauna selected to meet your personal requirements - current lead time 6-8 weeks. Exact delivery date to be shared upon order - please reach out for more details.