A glass door flanked by full-height tempered panels is the most-requested upgrade on a custom sauna. This guide covers where to buy a glass front online for any budget and exactly how to frame, seal, and heat-size one onto a sauna planned in SaunaDesignPro.
Both reference saunas — the Auroom Cala Glass (indoor) and Mira L (outdoor) — use the same recipe: a hinged glass door set into a full-height fixed glass wall in 8 mm tempered safety glass, with a cool-touch handle and self-closing hinges. The framing is deliberately minimal so the wall reads as glass. "Same or better" means 8 mm tempered as the floor, 10 mm for very large spans, always sauna-rated.
SaunaDesignPro's Marketplace carries only a couple of ProSaunas doors and Thermory framed panels, so this field guide exists to help customers source a full tempered-glass front from any supplier and build it onto a SaunaDesignPro shell — barrel, cube, indoor room, or a custom design. It covers four sourcing paths, two build methods with diagrams, and the heater-sizing math glass demands.
Spec floor
8 mm tempered glass
Large spans
10 mm tempered
Sourcing paths
4 (kit, modular, components, frameless)
Build methods
2 (framed sandwich, frameless)
Heater rule
Add ~1–1.5 cu ft of volume per sq ft of glass
Heater clearance
12–18" electric; 18"+ wood stove
Door air gap
3/4"–1" under the door (fresh-air intake)
The glass rules that govern every option
Whichever path you choose, the same physics apply. Get these wrong and it's a safety issue, not a finish issue.
Tempered only — never residential windows. Tempered safety glass is about four times stronger than annealed, shrugs off thermal shock, and crumbles into blunt granules instead of shards. House-window vinyl, aluminum, or pine frames melt, warp, or degrade.
Single pane beats dual pane. There's no sealed air gap to fail under daily heat cycling; failed dual-pane seals trap permanent condensation. Reserve insulated dual-pane for outdoor saunas in genuinely brutal winter climates.
You cannot modify tempered glass after it's made — it can't be cut, drilled, or ground. Frame the opening, measure it at multiple points, then order the glass.
Tint and privacy options: clear/low-iron for maximum light, bronze tint, frosted/etched, or one-way mirror (which reverses at night).
Four ways to buy a glass front online
Ordered roughly by how much building the customer wants to do. Path C reproduces the Auroom look most faithfully for the money; Path D pushes past it to fully frameless.
Path A — Turnkey kit: buy the whole sauna. The Cala Glass and Mira L ship as flat-pack kits with the glass front engineered in.
Path B — Modular framed system: bolt-together prefabricated framed 8 mm tempered glass sections that lock together on an aluminum floor channel (e.g. Tylo / TyloHelo GLASPARTI panels).
Path C — North-American component build: a pre-hung 8 mm frameless tempered door on a wood jamb (ProSaunas, Scandia, Almost Heaven) flanked by framed sidelight panels. Best value and most faithful Cala/Mira result.
Path D — Architectural frameless: order bare custom-cut tempered panels (8–10 mm) from a US fabricator and hang them with frameless hardware. Use all-metal, temperature-rated fittings.
Anatomy of a glass front
A full glass front is almost always one outswing glass door plus one or two fixed glass panels set into a structural opening. The glass carries none of the building's weight — a header and jack studs do that; the glass just fills the hole. The door swings out for safety, hangs on self-closing hinges, wears a cool-touch handle, and keeps a 3/4"–1" bottom gap that also feeds fresh air.
Build method 1 — the framed "sandwich" method (DIY-friendly)
The approach behind Path C and the one most home builders should use: sandwich each fixed panel between two slim wood stops cut from the same species as your cladding, and hang the pre-hung door in its jamb — no specialty glazing tools.
Frame a plumb, square opening to your glass size + 1/2" in width and height, with a header and jack studs.
Measure at top/middle/bottom and both sides/center, use the smallest reading, then order door and panels together as a matched set.
Rip stops ~1–1.5" wide from cedar, thermo-aspen, or hemlock (never pine, vinyl, or aluminum); set exterior stops first with a continuous clear-silicone bead.
Set the glass on cork/foam setting blocks (never wood-to-glass contact) — a 3′x6′ pane is ~55–60 lb, so it’s a two- or three-person job.
Add interior stops snug, not tight; over-driven screws create stress points that crack glass during heat cycling.
Seal both faces, slope the interior sill into the room so condensation drains inward, hang the door, and let silicone cure ~24 hrs before the first fire.
Size the heater for the glass
Glass is a heat sink — it dumps warmth out of the room far faster than an insulated wall. Add a glass front without upsizing the heater and you get long heat-ups and a sauna that never quite gets there.
The rule: add roughly 1 to 1.5 cubic feet to your volume calculation for every square foot of glass, then size the heater to that adjusted volume. Auroom's own guidance for the all-glass-front Mira L (~268 cu ft interior) is 9 kW in most climates and 10.5 kW where it's cold.
Worked example: a 6′ x 6′ x 7′ room is 252 cu ft (~5–6 kW bare); a 6′ x 7′ (42 sq ft) glass front adds +42 to +63 cu ft, giving about 294–315 cu ft and 6–8 kW — often a full size up.
Keep at least 12–18" of clearance between an electric heater and any glass (18"+ for a wood-burning stove), and follow the heater’s own minimums.
Ventilation, indoor/outdoor, and mistakes to avoid
Keep the glass fixed — operable windows are a liability. Pair fixed glass with a low fresh-air intake near the heater and a high exhaust on the opposite wall; the 3/4"–1" door gap is supplemental make-up air.
Don't order glass before the opening is framed and measured — tempered can't be trimmed.
Never use non-tempered glass — it can shatter into shards from thermal shock.
Don't forget glass in the heater math — a full glass front can add 40%+ to effective heating volume.
No vinyl, aluminum, or pine framing — vinyl melts, aluminum makes hot spots, pine bleeds sap.
Always leave a ~1/2" expansion gap, and never use a flat or reverse-sloped sill (it traps water and grows mold).
Frequently asked questions
What glass do I need for a sauna front?
Tempered safety glass only — 8 mm as the spec floor, 10 mm for very large spans, always sauna-rated. It is about four times stronger than annealed glass, resists the thermal shock of loyly, and crumbles into blunt granules instead of shards if it breaks. Never use residential windows with vinyl, aluminum, or pine frames.
Single-pane or dual-pane glass?
Single-pane tempered is right for nearly all installs — there is no sealed air gap to fail under daily heat cycling, and failed dual-pane seals trap permanent condensation between the panes. Reserve insulated dual-pane glass for outdoor saunas in genuinely brutal winter climates.
How does a glass front change heater sizing?
Glass acts as a heat sink, so add roughly 1 to 1.5 cubic feet to your room-volume calculation for every square foot of glass, then size the heater to that adjusted volume — often a full size up. Keep the heater 12–18" off the glass (18"+ for a wood stove).
Which sourcing path most faithfully matches the Cala/Mira look?
Path C — a pre-hung 8 mm frameless glass door plus framed tempered sidelights, framed into your shell — is the best-value, most faithful result for standard DIY carpentry.