Your sauna door does more than open and close. It holds heat inside the room, keeps bathers safe, and sets the visual tone for the entire space. Choosing the wrong size, swing direction, or glass type can mean failed inspections, wasted energy, or an uncomfortable sauna experience. Whether you're building a custom sauna from scratch or replacing a worn-out door on an existing room, this guide covers everything you need to make the right decision — from rough opening measurements to building code requirements for outswing doors.
Sauna Door Sizing: Standard Dimensions and How to Measure
Sauna doors are narrower and sometimes shorter than standard residential doors. Most sauna doors come in widths of 24 inches, 30 inches, or 36 inches, with heights of either 72, 73, 77, or 80 inches. The most common residential sauna door size is 24 inches wide by 80 inches tall, which fits comfortably in a standard stud-framed wall while minimizing the opening that allows heat to escape every time someone enters or exits.
Smaller 24-inch-wide doors are ideal for compact home saunas because the narrower opening reduces heat loss. Larger 30-inch and 36-inch doors are used in commercial saunas, ADA-compliant installations, and situations where a wider entrance is preferred for comfort or accessibility. If you're building a sauna that needs to meet ADA accessibility standards, a 36-inch-wide door is typically required to accommodate wheelchair access — you can find purpose-built options in our ADA-compliant sauna collection.
Understanding Rough Openings
The rough opening is the framed hole in your wall where the door will be installed. It needs to be larger than the door itself to allow room for the door frame (jambs), shimming, and adjustment during installation. As a general rule, your rough opening should be approximately 2 inches wider and 2 inches taller than the door size. For example, a 24-inch by 80-inch door typically requires a 26-inch by 82-inch rough opening.
Always check the manufacturer's specifications for the exact rough opening dimensions, as these can vary between brands. A Scandia cedar sauna door in 24x80, for instance, calls for a 27½-inch by 82¼-inch rough opening, while ProSaunas doors have their own specific requirements listed on each product page. Measuring incorrectly is one of the most common mistakes in DIY sauna builds, so take the time to get this right before ordering.
Choosing the Right Door Height
Some sauna builders deliberately choose shorter doors — 72 or 73 inches tall instead of the standard 80-inch residential height. The logic is simple: hot air rises and pools at the ceiling. A shorter door creates a larger gap between the top of the door frame and the ceiling, which helps trap that valuable layer of hot air inside the sauna even when the door is opened briefly. This is especially effective in saunas with 7-foot ceilings, where the door height makes a noticeable difference in heat retention.
That said, 80-inch doors are the more popular choice for home saunas because they feel natural and comfortable for taller users. If your sauna has an 8-foot ceiling, an 80-inch door still leaves over a foot of wall above the frame to trap hot air, which is more than enough for strong performance. Our ProSaunas 24x73 glass sauna door is a great option if you want the shorter profile, while the ProSaunas 24x80 tinted glass door gives you full residential height with a modern frameless look.
Inswing vs. Outswing: Why Sauna Doors Must Open Outward
This is one of the most important safety considerations in sauna design, and it is non-negotiable: sauna doors must swing outward, away from the interior of the sauna room. This is not simply a preference or a tradition — it is a safety requirement rooted in building codes and common-sense risk prevention.
The Safety Case for Outswing
Saunas operate at extreme temperatures, often between 150°F and 220°F. In that environment, heat exhaustion, dizziness, and even loss of consciousness are real possibilities, especially for first-time users or those who stay in too long. If a bather collapses near the door of an inswing sauna, their body could block the door from opening, trapping other occupants inside a dangerously hot room with no way out. An outswing door eliminates this risk entirely — even if someone falls against the door, it can still be pushed open from the inside.
There is also a practical ventilation benefit. An outswing door does not take up floor space inside the sauna when opened, which matters in compact rooms where every square foot counts for bench placement, heater clearance, and safe circulation. If you're planning a smaller build, our DIY sauna building guide covers layout planning in detail.
Building Code Requirements for Outswing Doors
Multiple building codes and standards address sauna door swing direction. The International Building Code (IBC) Section 1010.1.2 requires doors to swing in the direction of egress travel when serving 50 or more occupants or in high-hazard occupancies. While most residential saunas fall below the 50-person threshold, the broader principle of egress safety still applies, and many local jurisdictions enforce outswing requirements for saunas regardless of occupancy count.
New York City's health code for saunas and steam rooms, for example, explicitly requires doors that swing outward freely or are of a free-swinging type. The ADA Standards for Accessible Design (Section 612) address sauna and steam room doors specifically, requiring that doors not swing into the clear floor space at accessible benches. Many state and local health departments impose their own outswing requirements for commercial saunas as a condition of operating permits.
For residential installations, while enforcement varies by jurisdiction, virtually every sauna manufacturer, industry group, and experienced builder recommends outswing doors as a baseline safety practice. Every pre-hung sauna door we carry at Haven of Heat is designed to open outward from the sauna room. If your local building inspector reviews your sauna project, an inswing door will almost certainly be flagged.
What About Latches and Locks?
Sauna doors should never have locks that could trap someone inside. Most sauna doors use simple magnetic catches or roller latches that keep the door closed during use but can be pushed open with minimal effort from either side. Spring-loaded hinges are also common — they gently pull the door closed after entry but never lock it. The goal is a door that stays shut to retain heat but can always be opened easily, even by someone who is disoriented or physically weakened from the heat. This is another reason to avoid repurposing standard household doors for sauna use — their latch mechanisms are not designed with this safety consideration in mind.
Glass Sauna Doors: Tempered vs. Insulated Glass
Glass has become the most popular material for sauna doors, and for good reason. A glass sauna door lets natural light into the room, creates an open and airy feel, makes the sauna look more spacious, and allows people outside to see in for safety monitoring purposes. But not all glass is appropriate for sauna use, and understanding the differences between tempered and insulated (dual-pane) glass is essential.
Tempered Glass: The Standard for Sauna Doors
Tempered glass is the industry standard for sauna doors, windows, and walls. It is manufactured through a process of extreme heating and rapid cooling that makes it approximately four times stronger than standard annealed glass of the same thickness. Tempered glass used in sauna applications can withstand temperatures up to 470°F — well above the maximum 230°F that saunas typically reach — and it handles thermal shock from sudden temperature changes, such as when cold water splashes against a hot door.
The most critical safety feature of tempered glass is how it breaks. If it does shatter (which is rare under normal sauna conditions), it breaks into small, rounded granular pieces rather than the large, sharp shards that standard glass produces. In a sauna where people are barefoot and often have wet skin, this is a crucial safety distinction. The IBC (Section 2406) specifically requires safety glazing in sauna enclosures, and tempered glass meeting CPSC 16 CFR 1201 standards satisfies this requirement.
Most glass sauna doors use 5/16-inch (8mm) tempered glass for frameless designs, which provides an excellent balance of strength, weight, and thermal performance. Our ProSaunas pre-hung frameless glass doors use 8mm tempered glass and are available in both clear and tinted options across multiple frame wood species.
Insulated (Dual-Pane) Glass
Insulated glass consists of two panes of glass separated by an air gap (typically around 11mm), sealed together as a unit. The trapped air between the panes acts as an insulating layer, reducing heat transfer through the glass. The Scandia cedar sauna door, for example, features dual-pane 4mm-thick glass with an 11mm air space, offering noticeably better insulation than a single pane of tempered glass.
Insulated glass doors are especially beneficial in these situations: outdoor saunas where the exterior temperature is very cold, saunas in unheated spaces like garages or basements, and any installation where you want to minimize heat loss through the glass to reduce the demand on your sauna heater. The trade-off is that insulated glass doors are heavier and typically more expensive than single-pane tempered glass doors.
There is one important consideration with insulated glass in sauna environments: over many years of extreme heat cycling, the seals between the two panes can eventually degrade, allowing moisture to enter the air gap and cause fogging between the panes. High-quality sauna-specific insulated glass doors are engineered with seals rated for the temperature range, but this is something to be aware of compared to single-pane tempered glass, which has no seal to fail. For custom glass walls and large window panels, single-pane tempered glass is often the preferred choice for this reason.
Clear vs. Tinted Glass
Both tempered and insulated glass sauna doors are available in clear and tinted (typically bronze) options. Clear glass provides maximum light transmission and full visibility into and out of the sauna, which is ideal for safety monitoring and for making the sauna feel open and connected to the surrounding space. Tinted bronze glass offers a warmer aesthetic, reduces glare, and provides a modest degree of privacy while still allowing you to see through the door. The tint does not significantly affect the thermal properties of the glass — it is primarily an aesthetic choice. Browse our full selection of glass sauna doors to compare clear and tinted options side by side.
Frameless Glass Sauna Doors: The Modern Standard
Frameless glass sauna doors have become the dominant style in contemporary sauna design, and most of the glass doors available today fall into this category. A frameless door uses a full sheet of tempered glass with no wood or metal frame around the glass panel itself. The glass is mounted directly to hinges, and the door hangs within a wooden jamb and header assembly that frames the opening — but the glass itself has clean, uninterrupted edges.
Why Frameless Doors Are Popular
The appeal is both visual and functional. Frameless designs create a sleek, minimal look that pairs well with modern sauna interiors, whether you're using thermo-aspen, alder, or cedar paneling. Without a frame wrapping the glass, the door feels lighter and more open, and the glass is easier to clean since there are no frame edges where moisture and residue can collect.
From a performance standpoint, frameless doors with proper door stops and magnetic catches seal well against the jamb, and the minimal hardware means fewer components that can corrode or degrade in the high-heat, high-humidity sauna environment. ProSaunas, one of our most popular door brands, builds all of their pre-hung glass doors in a frameless configuration with 8mm tempered glass, available with black alder, aspen, or thermo-aspen frames.
Frameless vs. Framed: Which Is Better?
Framed glass doors — where the glass panel is surrounded by a wood frame — are still available and have their place. They tend to offer slightly better insulation because the wood frame adds a thermal break around the glass, and some people prefer the traditional look. The Bathology Elements 310 and the Scandia combination doors with cedar frames and glass inserts are examples of high-quality framed or semi-framed options.
For most modern builds, however, frameless glass doors are the better choice. They look cleaner, maintain well in the sauna environment, and are widely available in all standard sizes. If you're building a contemporary sauna and want the most polished look, a frameless tempered glass door is the way to go.
Wood Sauna Doors: When They Make Sense
While glass dominates the market, wood sauna doors remain a strong choice for certain applications. A solid wood door provides the best insulation of any sauna door type, making it ideal for outdoor saunas in very cold climates where heat retention is a top priority. Wood doors also deliver a traditional Finnish sauna aesthetic that many purists prefer.
Cedar is the most popular wood for sauna doors because of its natural resistance to moisture, decay, and warping. It also stays relatively cool to the touch at sauna temperatures and has a pleasant natural aroma. Many wood sauna doors include a glass insert or window panel — this gives you the insulation benefits of a wood door while still providing visibility into the sauna for safety and a touch of natural light. These combination doors, like the Scandia cedar models with dual-pane glass inserts, are an excellent compromise between full glass and solid wood.
Pre-Hung Doors vs. Standalone: What to Buy
Almost every sauna door sold today comes pre-hung, meaning the door is already mounted on a frame with hinges attached and a threshold included. This is a significant advantage for both DIY builders and professional installers. A pre-hung door is easier to install because the door is already aligned within its frame, the hinges are properly set, and you simply need to shim and secure the entire assembly into your rough opening.
Buying a standalone door slab and building your own frame from scratch is possible but not recommended unless you have specific carpentry experience with sauna construction. The tolerance requirements are tighter than standard residential doors because the door needs to close firmly enough to retain heat without using a mechanical latch. Our sauna door installation guide walks through the full process for pre-hung doors step by step.
Sauna Door Materials: What to Look for in Frames and Hardware
The glass or wood panel gets most of the attention, but the frame, hinges, handles, and threshold are just as important for long-term performance in a sauna environment.
Frame Wood Species
The most common frame materials for sauna doors are cedar, aspen, thermo-aspen, black alder, and hemlock. Each has different characteristics. Cedar is naturally moisture-resistant and aromatic. Aspen is light-colored, smooth, and affordable. Thermo-aspen has been heat-treated for enhanced moisture resistance and a rich, darker appearance. Black alder offers a striking dark color that contrasts beautifully with clear glass. When choosing a door, consider how the frame wood will coordinate with your interior sauna wall paneling and bench materials for a cohesive look.
Hinges
Sauna door hinges need to handle the weight of the door (glass doors with frames can weigh 150 to 200 pounds) while resisting corrosion from heat and humidity. Most quality sauna doors use two or three heavy-duty hinges made from stainless steel or aluminum with protective coatings. Spring-loaded hinges that automatically close the door are common and help maintain heat retention between entries. Look for hinges with adjustable tension so you can control how aggressively the door self-closes.
Handles
Sauna door handles must remain cool enough to grip safely at sauna temperatures. The standard design uses a wooden handle on the inside of the door (since wood conducts heat poorly) and either a wooden or stainless steel handle on the outside. ProSaunas doors, for example, feature a brushed stainless steel handle on the exterior and a wood handle on the interior — a practical design that looks sharp while keeping sauna users safe from burns.
Sauna Door Placement and Ventilation Considerations
Where you place your sauna door affects both the room's heat performance and the quality of air circulation. In most sauna layouts, the door is positioned on the wall opposite or adjacent to the heater, never directly next to it. This placement creates a natural airflow path: fresh air enters through a lower intake vent near the heater, heats up, rises, circulates across the bathers on the upper bench, and exits through a higher exhaust vent on the far wall.
The small gap at the bottom of a sauna door (typically ¾ inch to 1 inch) also contributes to airflow and can act as a supplemental fresh air intake. If your sauna is sealed too tightly with no gap under the door and insufficient ventilation, the air quality inside will suffer and the heater may struggle to produce good steam. Proper ventilation is covered in depth in our sauna insulation guide and vapor barrier best practices article.
Glass Windows and Walls: Expanding Beyond the Door
If you love the look of a glass sauna door, you may want to extend the glass to include a full glass wall, sidelight panels, or additional windows. This is increasingly common in modern sauna design and creates a truly stunning finished room. Our custom tempered glass panels can be ordered in any size or tint for full glass walls or large windows, and our round tempered glass sauna windows are a popular option for adding a design accent to wood-clad walls.
When planning a glass wall, use single-pane tempered glass (not insulated) to avoid long-term seal failure from heat cycling. The glass should be at least ¼ inch thick for windows and 5/16 inch or more for full wall panels. All glass in sauna enclosures must be safety-rated per the IBC, so tempered glass is required — standard window glass is never acceptable. For a full walkthrough on the installation process, see our guide to adding a glass wall to your sauna.
Common Mistakes to Avoid When Buying a Sauna Door
Using a standard residential door. Regular interior doors are not built for sauna conditions. They will warp, delaminate, and potentially off-gas harmful chemicals when exposed to sustained heat above 150°F. Standard door hardware can also become dangerously hot. Always use a purpose-built sauna door.
Ordering the wrong rough opening size. Measure twice, order once. Check the manufacturer's exact rough opening specifications rather than assuming a standard 2-inch oversize will work. Getting this wrong means either a door that does not fit or costly reframing.
Choosing the wrong hinge side. Sauna doors are available with hinges on the left or right. The hinge position is determined while standing outside the sauna, facing the door. Left hinge means the hinges are on your left and the handle is on your right. Think through your room layout, bench placement, and traffic flow before ordering.
Ignoring heater sizing. Glass doors, while beautiful, do not insulate as well as solid wood doors. If you choose a full glass door (especially a large one), you may need a slightly more powerful sauna heater package to compensate for the additional heat loss through the glass. This is especially true for outdoor saunas or saunas in unheated spaces. Use our sauna heater sizing resources to confirm you have the right kW rating for your room size, insulation level, and door type.
Forgetting about clearance. Since the door swings outward, you need clear space on the exterior side. Make sure no furniture, walls, fixtures, or traffic paths are within the door's swing arc. This is especially important in basement saunas and tight indoor installations.
How to Choose the Right Sauna Door for Your Build
Selecting the right door comes down to matching your priorities with the right product type. For a modern, clean look with maximum natural light, a frameless tempered glass door from ProSaunas in either clear or tinted glass is the top choice. For maximum insulation in a cold-climate outdoor sauna, a wood door with an insulated glass insert (like the Scandia cedar models) will serve you best. For commercial or ADA-accessible installations, a 36-inch-wide ADA door ensures compliance and easy access for all users.
If you're tackling a full DIY sauna room kit or building a custom sauna from the ground up, the door is one of many components you'll need to coordinate. Browse our complete sauna door collection to see every option we carry, and explore our full lineup of sauna accessories to complete your build. If you want help choosing the right door for your project, our product experts are available anytime at 360-233-2867.
*Haven Of Heat and its affiliates do not provide building, electrical, or professional advice. All content is for general informational and educational purposes only. Always consult licensed contractors, inspectors, or local authorities for installation, building code, and safety requirements specific to your location.
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