Beancross Rd, Polmont, Falkirk FK2 0XS Open today · 9am–5:30pm 07367 086350 07861 958262 AboutAbout Our story & team Reviews Verified Google reviews Garden RoomsAll Garden Rooms Explore the full range Home Offices Work-from-garden studios Garden Gyms Private fitness spaces Garden Bars & Lounges Entertain in style Annexes & Guest Rooms Extra living space SaunasBarrel Saunas Jonas Grand From £8,995 Jonas Grand From £8,995 Jonas S From £6,495 Jonas Teak From £6,995 Joris Grand From £9,495 Teak From £8,495 Cube Saunas Ebony From £10,995 Ebony From £10,495 Ula Classic Beige Full-Glass From £9,995 Ula L From £11,495 Ula L From £12,495 Ula Micro From £8,495 Ula Mini From £8,995 Ula Mini From £9,495 Ula Mini From £9,295 Modular Saunas Celsium Herkus L From £12,995 Tauras Grand Ebony From £16,995 Tauras Modular Air with Aiste Grand Hot Tub From £19,995 Hot TubsAll Hot Tubs Wood-fired thermowood soaking tubs Aiste Grand From £6,995 Benas From £5,495 Log CabinsAll Log Cabins 30 designs, 34mm to 68mm walls Cabin Range & Prices Full 2026 price list Cabin Photo Gallery Real Scottish installations Sheds, Garages & Summerhouses From £500, installed 2026 Shed Price List Sheds, garages, playhouses Glamping & Residential Cabins Pods, barrels & lodges Other ServicesBBQ Huts Year-round outdoor cooking Glamping & Residential Holiday-let & annex builds Sheds, Garages & Summerhouses From £640, installed Outdoor Kitchens Built for Scottish weather Composite Decking Low-maintenance decks Bespoke Design Service Full design & build Our WorkRequest Estimate Modular Saunas # Celsium Herkus L.Architectural modular. Zero compromise. A premium modular cube sauna in charred timber with panoramic glass, the design-led flagship of our modular range. Request Your Estimate 07367 086350From £12,995 · Delivered & installed Overview ## Celsium Herkus L Modular Sauna. The Celsium Herkus L is our design-led modular flagship, a properly-insulated cube sauna in Shou Sugi Ban charred timber, with a full-height panoramic glass end wall and a Harvia heater that reaches temperature in 30 minutes. Unlike a barrel, a modular cube is a fully-insulated timber-frame structure, 100mm rockwool between studs, vapour barrier, and knot-free western hemlock interior lining. It costs more to build, but it holds temperature, sits square into architectural garden schemes, and gives you a full-height interior rather than a curved ceiling. This is the sauna to specify when the garden is a design piece rather than a lawn, sitting alongside a garden room, next to a hot tub deck, or as a standalone architectural feature in a contemporary courtyard. Key features ## What makes it different. ### Fully-insulated cube construction 100mm rockwool insulation between timber studs, vapour barrier, interior hemlock lining. Holds temperature 30% better than an uninsulated barrel. ### Shou Sugi Ban ebony exterior Charred and oiled spruce cladding, architectural black that ages to graphite. ### Panoramic glass wall Full-height toughened glass end wall with matching glass door. ### Harvia electric heater 9kW Finnish-made heater with rock cradle and digital control panel. ### Full-height interior Genuine 2.1m ceiling height, you can stand comfortably (barrels can't offer this). ### Bespoke sizes available This is the L; also available as M and XL. Interior layouts can be tailored to your space. Specification ## The numbers behind the object. Capacity5–6 adults External footprint3.0 x 2.4 m Interior ceiling height2.1 m Cladding (exterior)Shou Sugi Ban charred spruce Insulation100mm rockwool Lining (interior)Knot-free western hemlock HeaterHarvia electric 9kW Heat-up time≈ 30 minutes Power requirement3-phase 400V or 32A single-phase RoofEPDM flat, hidden gutter Warranty10 yr structural Living with it ## How it actually works day to day. Insulation is the single biggest reason to spend more on a modular over a barrel. The Herkus L holds soaking temperature with the heater at low duty-cycle, meaning the running cost across a Scottish winter is materially lower than an uninsulated wood barrel of the same capacity. The full-height interior changes the sauna experience. You can stand up to shower off between sessions, and the vertical wall lets you fit a wall-mounted backrest so tall users aren't compromised by the barrel curve. It's a modular product, the base spec is what you see, but panel sizes, glass layouts, bench configurations and finishes can all be tailored at order. We handle the bespoke consultation in our design service. Best for ## Who typically buys this one. - Design-led garden schemes where the sauna is an architectural feature - Buyers who want a fully-insulated sauna for lower running costs - Owners over 6' who find barrel ceilings restrictive - Clients wanting a bespoke interior layout or non-standard dimensions Real installations ## Celsium Herkus L in Scottish gardens. Every photograph on this page is a genuine Signature Garden Rooms installation. Frequently asked ## Straight answers. If your question isn't listed, call Ryan on 07367 086350. Why choose a modular over a barrel?Three reasons: (1) insulation, modular holds temperature far better, lower running cost; (2) architectural fit, cubes sit square into modern garden schemes; (3) headroom, 2.1m ceilings mean tall users aren't stooped. Barrels are cheaper and heat faster; the choice depends on how much you'll use it and how it sits in the garden. How long does it take to heat up? Can it be customised? Does it need a foundation? What power does it need? How is the roof detailed? How long is the warranty? What's the lead time? Next step ## Ready to talk about the Celsium Herkus L Modular Sauna? Tell us your garden, your access, and roughly when you'd like it in. We'll come back with a considered price, honest lead time, and any planning notes for your site. Request Your Estimate 07367 086350 Fully insured · £5m public liability · Falkirk-based, working across Central Scotland Explore the site ## Popular pages & service areas Other services - insulated bespoke garden rooms in Falkirk - premium log cabins in Central Scotland - Nordic BBQ huts for Scottish gardens - saunas and hot tubs supplied and installed - outdoor kitchens built for Scottish weather - composite decking installers near you - timber sheds, garages and summerhouses - bespoke garden building design and build - garden rooms in Falkirk - garden rooms in Stirling - garden rooms in Glasgow - garden rooms in Edinburgh - garden rooms in Livingston - garden rooms in Dunfermline - recent installs across Central Scotland - verified Google reviews (4.6★) Bespoke, fully-insulated garden rooms designed and built across Falkirk and Central Scotland. Explore - Garden Rooms - All Services - Our Work - Service Areas - About - Reviews Contact - Beancross Rd, Polmont,Falkirk FK2 0XS - 07367 086350 - 07861 958262 - ryan@amrgardenbuildings.co.uk Opening hours - Mon – Fri9:00 – 17:30 - Saturday9:00 – 17:00 - Sunday9:00 – 16:00 Leave a Google review © 2026 Signature Garden Rooms. All rights reserved. · Formerly AMR Garden Buildings · Owned and run by Ryan Meldrum PrivacyCookiesTermsContact CallRequest Estimate