Bespoke Indoor Sauna Installation: Clarendon Road

The Clarendon Road project is a standout example of what Finnmark Sauna’s bespoke installation service can achieve. Designed and built entirely around the client’s vision of a premium, relaxation-focused sauna, this installation transformed a dedicated room within a residential property into a fully bespoke Finnish sauna experience. From the initial consultation through to the seven-day on-site build, every element was carefully selected, crafted, and installed by our specialist team to deliver a space that is as beautiful as it is functional.

What makes Clarendon Road particularly noteworthy is the level of customisation involved. This was not a modular cabin dropped into a room; it was a ground-up bespoke build that had to work within the constraints of an existing residential space, including walls that were not fully square. The result is a sauna that feels entirely intentional, as though the room was always designed for this purpose. It is a testament to the precision and adaptability of our installation team, and a showcase for the premium materials and components we work with.

Project Specification

The Heater: IKI Pillar 10kW

At the heart of every authentic sauna is the heater, and for Clarendon Road, we specified the IKI Pillar 10kW, one of the most respected electric sauna heaters available. Manufactured by hand in Pieksämäki, Finland, IKI Kiuas has been at the forefront of open-structured heater design for decades. The word “IKI” itself means “forever” in Finnish, and that philosophy of lasting quality is evident in every detail of their construction.

The IKI Pillar 10kW is engineered for sauna rooms between 10 and 18 cubic metres, making it ideally suited to a generously proportioned residential sauna of this kind. Its defining characteristic is the massive stone capacity, approximately 170 kilograms of sauna stones housed within a signature stainless steel mesh frame. This large stone mass is what sets IKI heaters apart from conventional wall-mounted units. The stones absorb and radiate heat evenly, and when water is thrown onto them – not just on the top, but also through the open mesh sides, they produce a soft, humid, oxygen-rich löyly (steam) that is the hallmark of an authentic Finnish sauna experience.

The Pillar’s slim, vertical profile was a key factor in its selection for Clarendon Road. Despite its impressive power output and substantial stone load, the heater’s compact footprint meant it could be seamlessly integrated into the bench system without dominating the room. IKI offers a dedicated stainless steel embedding flange for precisely this purpose, enabling the heater to sit flush within the bench structure. This integration is a technique our installation team employs on bespoke builds to create a cleaner, more cohesive aesthetic – the heater becomes part of the architecture of the sauna rather than an appliance sitting in the corner.

Free airflow through the stainless steel mesh, combined with the large contact area between IKI’s specially designed U-shaped resistors and the stones, enables a heating time of approximately one hour from cold. For the homeowner, this means the sauna can be ready to use with minimal planning, a practical consideration that makes all the difference in encouraging regular use.

It is worth noting that a bespoke, custom-made heater guard was designed and manufactured for this installation. Due to the heater’s integration into the bench structure, safety clearance distances technically require a guard. However, after the installation was completed, the client chose to remove the guard for aesthetic reasons. The guard remains available should they wish to reinstall it at any time.

The Controller: UKU Glass Wi-Fi

Paired with the IKI Pillar is the UKU Glass Wi-Fi controller, a sleek, black glass touchscreen panel that brings modern convenience to the sauna experience. The UKU Glass can be wall-mounted outside the sauna room, keeping it protected from the heat and humidity while remaining easily accessible. Its minimalist design is entirely in keeping with the contemporary aesthetic of the Clarendon Road build.

The standout feature of the UKU Glass is its Wi-Fi connectivity. Through the dedicated IKI mobile application, the homeowner can start heating the sauna remotely, whether they are on their way home from work, finishing a gym session, or simply relaxing in another part of the house. The app allows full control over temperature settings, heating schedules, and timer functions, and even provides a real-time temperature curve so you can monitor the sauna as it reaches your preferred bathing temperature. This kind of smart integration elevates the sauna from a passive amenity into something the homeowner actively engages with as part of their daily routine.

Timber Selection: Thermo Alder

Timber is the defining material of any sauna, and for Clarendon Road, the client selected Thermo Alder for both the wall cladding and the bench surfaces. This was a carefully considered choice that delivers on both aesthetics and performance. For a deeper exploration of the timber options available for your sauna build, see our comprehensive guide: Best Wood for Saunas (& Why).

Thermo Alder is created through a thermal modification process in which natural Alder wood is heated to temperatures of approximately 190°C in a controlled, oxygen-free environment using only heat and steam; no chemicals or preservatives are involved. This process fundamentally changes the wood’s cellular structure, transforming its light natural colour into a warm, rich shade of brown while dramatically enhancing its dimensional stability and moisture resistance. The result is a timber that retains the smooth, knot-free texture of natural Alder but is far less susceptible to the warping, swelling, and shrinkage that can affect untreated wood in the extreme conditions of a sauna.

For the wall cladding, Thermo Alder 140’s were used, a wider profile board that creates a clean, contemporary look with fewer visible joints. The wider boards lend the walls a sense of calm and simplicity, allowing the natural grain and warm tonal variation of the timber to take centre stage. On the benches, the same Thermo Alder was used, ensuring a unified material palette throughout the room. Critically, Thermo Alder has naturally low heat conductivity, meaning the bench surfaces remain comfortable to sit and lie on even at high sauna temperatures. This is a non-negotiable consideration for any sauna wood, and Thermo Alder delivers it without compromise.

The near-neutral aroma of Thermo Alder was also a factor in its selection. Unlike Western Red Cedar, which has a strong and distinctive scent, Thermo Alder is virtually scent-free. This makes it an ideal base material for clients who prefer to introduce their own aromatic elements, essential oils, sauna infusions, or, as in this case, the natural fragrance of a juniper feature wall.

The Juniper Feature Wall

One of the most striking elements of the Clarendon Road sauna is the juniper feature wall, complete with upstand lighting that draws the eye and creates a warm, ambient glow. Juniper decorative panels are handcrafted from cross-cut slices of real juniper stems, arranged in a mosaic pattern that is entirely unique to each panel. No two installations are alike, and this natural variation gives the feature wall an organic, artisan quality that contrasts beautifully with the clean, linear profile of the Thermo Alder cladding and benches.

Beyond its visual impact, juniper is prized for its aromatic and therapeutic properties. When the sauna heats up and humidity rises, the juniper panels release their characteristic essential oils, filling the room with a fresh, forest-like fragrance. Juniper oil has long been associated with respiratory benefits, improved blood circulation, and antiseptic properties. In Finnish and Baltic sauna traditions, juniper has been a staple of the bathing experience for centuries, and incorporating it into a modern bespoke build like Clarendon Road connects the homeowner to that heritage in a meaningful, sensory way.

The upstand lighting behind the juniper wall is a carefully considered design detail. Positioned to cast light upward across the textured surface of the juniper mosaic, it accentuates the depth and dimension of the crosscut stems, creating shadows and highlights that shift subtly as the viewer’s perspective changes. The effect is warm, inviting, and distinctly premium, turning what could be a simple wall into the focal point of the entire room.

Bespoke Details and Craftsmanship

The Custom Window Liner

One of the more technically demanding aspects of the Clarendon Road installation was the bespoke window liner. The existing room featured a window that needed to be retained, and our team designed and fabricated a custom timber liner to frame it within the sauna interior. The challenge here was that the existing walls were not fully square, a common reality in residential properties, particularly period or older homes. Our installation team scribed the window liner on site, carefully measuring and trimming the timber to achieve a perfect fit against the irregular wall surfaces. This kind of precision work cannot be prefabricated in a workshop; it requires experienced hands, sharp eyes, and the patience to get it right on site. The finished result is seamless, with the window appearing as a natural, designed element of the sauna rather than a compromise.

Frost White Cerakote Hardware

The door handle and hinges were finished in Frost White Cerakote, a ceramic-based coating originally developed for the firearms industry and now widely used in high-end applications where durability, corrosion resistance, and a flawless finish are required. Cerakote withstands extreme temperatures and is highly resistant to moisture, making it an ideal choice for sauna hardware that will be exposed to heat and humidity on a daily basis. The Frost White colour was chosen to complement the warm tones of the Thermo Alder and juniper, providing a crisp, clean contrast that reinforces the contemporary feel of the design. It is a small detail, but one that speaks to the level of consideration that goes into every Finnmark bespoke project.

Under-Bench Speaker System

To complete the sensory experience, under-bench speakers were installed, allowing the homeowner to play music, podcasts, or ambient soundscapes during their sauna sessions. Positioning the speakers beneath the bench keeps them hidden from view, maintaining the clean aesthetic of the interior while delivering sound that fills the room from below. Whether the client prefers to unwind with calming music or listen to something more energising, the integrated audio system makes the sauna a truly immersive retreat.

Bench Layout: Designed for Lying Down

The bench layout at Clarendon Road was specifically designed with lying down as the primary bathing position. In Finnish sauna culture, lying flat on the upper bench is considered the ideal way to bathe; it allows the body to be at a consistent temperature from head to toe, promotes deeper relaxation, and enables the bather to fully surrender to the heat. Many residential saunas are designed primarily for seated use, often due to space constraints. At Clarendon Road, the room dimensions allowed our design team to prioritise a generous, full-length upper bench that comfortably accommodates lying flat, making this a sauna that encourages a more traditional, meditative approach to bathing.

The Installation Process

The Clarendon Road sauna was completed over a seven-day on-site installation by our specialist fitting team. A bespoke build of this complexity requires careful sequencing – from the initial preparation and insulation of the room, through the framing and cladding of walls, to the construction of the bench system, integration of the heater, fitting of the door and window liner, installation of the juniper feature wall and lighting, and the final connection of the audio system and controller. For those considering building their own sauna, our DIY Sauna Build Guide provides comprehensive step-by-step instructions.

Each stage demands precision. The scribing of the window liner to accommodate walls that were not fully square is just one example of the kind of adaptive craftsmanship that distinguishes a Finnmark bespoke installation from a standard fit-out. Our team brings years of experience to every project, and that expertise is what allows us to deliver results of this calibre consistently.

It is important to note that the property's external cladding was not included in Finnmark's scope of work for this project. Our involvement was focused entirely on the interior sauna build, the design, material supply, and installation of the sauna room itself.

Why Choose a Bespoke Sauna Installation?

The Clarendon Road project illustrates the advantages of choosing a bespoke sauna installation over a standard modular cabin. A modular sauna is designed to fit a generic space; a bespoke build is designed to fit your space, your preferences, and your lifestyle. Every dimension, material, and component is selected and configured to create something that is uniquely yours.

With a bespoke installation from Finnmark Sauna, clients benefit from access to our full range of premium Finnish heaters, our extensive selection of sustainably sourced sauna timbers, and the expertise of our in-house design and installation team. We manage the entire process from initial consultation through to completion, ensuring that every detail is considered and every standard is met. Explore more of our completed projects in our sauna case studies.

As the UK’s first “Sauna from Finland” certified retailer, Finnmark Sauna brings an unmatched depth of knowledge and authenticity to every project. Whether you are looking to convert an existing room, build a garden sauna, or integrate a sauna into a new-build or renovation, our team is here to guide you through every step.

Interested in a bespoke sauna installation? Contact our team today to arrange a free consultation and discover how we can bring your sauna vision to life.