Keep the washitsu (和室, Japanese-style room) or convert it to a Western-style room? That is the question INA&Associates hears from property owners on a daily basis. This article moves beyond intuition and draws together data from MLIT (Ministry of Land, Infrastructure, Transport and Tourism; 国土交通省) housing surveys, the 2023 revised Genjō-kaifuku Guideline (原状回復ガイドライン, Japan's MLIT restoration-to-original-state guidelines), and trends from our own managed portfolio to give owners a practical decision framework — including wa-modern interior design principles and common pitfalls to avoid. The article is supervised by our CEO, Daisuke Inazawa (Licensed Real Estate Transaction Specialist / Chintai Fudōsan Keiei Kanrishi — 宅地建物取引士／賃貸不動産経営管理士, Certified Rental Property Manager).

Key Takeaways

The share of homes with washitsu is declining, yet specific tenant segments still show a clear preference for them
Tatami resurfacing cycles run 6–8 years; flooring lasts roughly 15 years — on a simple cost comparison, conversion appears advantageous
The 2023 revised Genjō-kaifuku Guideline maintains the principle that ordinary tatami surface wear is the landlord's responsibility
The claim that "tatami is good for your health" has limited medical backing beyond its moisture-buffering properties
The height of a ko-agari (小上がり, raised tatami platform) — 30 cm, 40 cm, or 60 cm — fundamentally changes how the space functions

1. Do You Really Need a Washitsu? — Where Things Stand in 2026, by the Numbers

Whether a washitsu is necessary should be determined by data, not gut feeling. Cross-referencing housing statistics, rental search data, and our own transaction records reveals a more nuanced picture than a blanket "unnecessary" verdict would suggest.

Washitsu Prevalence Trends in Housing Market Surveys

The MIC (Ministry of Internal Affairs and Communications; 総務省) Housing and Land Survey and the MLIT Housing Market Trends Survey both show a long-term decline in the share of newly built custom homes that include a washitsu. While figures should be verified in the latest editions, the broad trend is clear: a rate that exceeded 70% in the 2000s has fallen to below 50% in recent years.

That said, this decline applies to the new-build flow, not the existing stock. The Housing and Land Survey shows that homes containing at least one washitsu still account for a substantial share of total housing stock. Given that the rental properties most of us manage are predominantly over 20 years old, "how to handle the washitsu" will remain a live operational question for at least the next two decades. Using new-build preference trends alone to justify blanket conversion of existing stock ignores location and tenant profile — and risks overshooting the mark.

Reading Rental Demand for Washitsu Through Search Data

Based on publicly available articles from portals such as SUUMO and LIFULL HOME'S, users who actively filter for "washitsu included" remain a minority of total searchers (exact figures are not disclosed by these platforms, so treat any specific numbers as estimates). However, segments with a clear preference for washitsu do exist: families, elderly single-person households, and inbound visitors seeking short-term stays.

The Japan Tourism Agency (観光庁) Survey on Consumption Trends of Inbound Visitors consistently shows that a meaningful share of overseas visitors prioritize an "authentically Japanese" accommodation experience. In the short-term rental and monthly-mansion segment, a washitsu can actually command a premium.

How Location and Target Tenant Flip the Value Equation

In practice, a washitsu cannot be labeled uniformly as either an "asset" or a "liability." The same room reads very differently depending on where the property sits and who you are trying to attract.

In suburban areas with strong demand from families or corporate-lease tenants, a washitsu tends to be a neutral-to-positive factor. Prospective tenants can immediately picture using it — for childcare, hosting overnight guests, placing a butsudan (家仏壇, Buddhist home altar), and so on — which makes it easier to convey during viewings. Conversely, in urban locations targeting single tenants in their twenties, a washitsu tends to be a negative: furniture layout is constrained and tatami carries a perception of being troublesome to clean, both of which drag down viewing scores.

When we conduct site surveys, we always check the age profile of commuters at the nearest station and whether a nursery, supermarket, or university exists within 500 meters. These neighborhood indicators are the final input for deciding whether to keep a washitsu. As a next step, articulate your target tenant profile in writing, then compare vacancy periods across at least three comparable listings on the portals. For a broader discussion of vacancy reduction strategy, see our article on vacancy management in rental property operations.

2. The Functional Case for Washitsu — Separating Evidence from Folklore

Claims about washitsu benefits range from well-supported to purely anecdotal. Here we go back to primary sources and draw a clear line between the two.

Moisture Buffering (Academic Data on Igusa Absorption and Release)

Multiple studies by NARO (National Agriculture and Food Research Organization; 農研機構) and the tatami industry have confirmed that igusa (い草, rush grass) absorbs and releases moisture. Publications available through NARO and building-environment engineering papers indexed on J-STAGE document how tatami surfaces respond to changes in ambient relative humidity.

That said, a tatami mat cannot regulate the humidity of an entire dwelling on its own. The order of magnitude for moisture absorption per tatami mat is a few hundred grams — meaningful, but only when combined with dehumidifiers and proper ventilation design. In older buildings without 24-hour mechanical ventilation, relying solely on tatami's moisture buffering is insufficient to lower the dew point, and mold on the underside of mats is a documented consequence. Treat moisture buffering as a supplementary benefit, not a selling point in isolation.

The layered structure of tatami — surface material over a straw or composite base — absorbs light impact noise more effectively than hard flooring. Research from BRI (Building Research Institute; 建築研究所) kenken.go.jp on floor impact sound confirms that surface flexibility contributes to reducing light impact noise.

For everyday noise from children running or objects being dropped, a washitsu has a clear advantage. Heavy impact noise, however, is a structural issue that tatami cannot address. Proposals to "switch to tatami" as a remedy for inter-floor noise complaints in apartments are a common misunderstanding — low-frequency heavy impact noise is barely affected. When marketing a washitsu to families with children, limit your claims to light impact noise reduction and be transparent about what tatami cannot do.

Versatility (Guest Room / Childcare / Altar / Remote Work)

A washitsu allows effortless switching between floor-level and standing use, making the space inherently multi-functional. A single six-mat room can serve as overflow guest sleeping space, a childcare area for naps and diaper changes, a home altar alcove, and a mental-reset nook for remote workers — none of which a Western-style room replicates as naturally. Since the pandemic, we have seen growing interest from clients who rediscovered the washitsu as a "decompression zone" during work-from-home hours. Even in custom-built detached homes, demand for a tatami corner adjoining the living room is recovering.

Fact-Checking the "Health Benefits" Narrative

Claims such as "sleeping on tatami improves back pain" or "the scent of igusa has a calming effect" have limited support in peer-reviewed medical literature. A search of PubMed and similar databases does not turn up sufficiently powered human-intervention trials to substantiate these claims. The physical properties — moisture buffering and impact absorption — are real and documented; "health benefits" as a primary marketing angle should be approached with caution. For advertising copy, stick to the demonstrable physical characteristics and avoid claims that go beyond the evidence.

3. Owner's Perspective: Lifecycle Cost of Keeping a Washitsu vs. Converting to Western-Style

This is the question owners care most about. Here is how the numbers compare.

Resurfacing Cycles and Maintenance Cost Benchmarks for Tatami, Fusuma, and Shoji

As a practical benchmark: tatami surface replacement (omote-gae) runs every 6–8 years at roughly JPY 4,000–12,000 (approx. $27–$80) per mat; full tatami replacement every 10–15 years at JPY 15,000–35,000 (approx. $100–$233) per mat (regional and grade variation applies — verify locally). Fusuma (襖, sliding paper doors) re-papering costs approximately JPY 2,000–6,000 (approx. $13–$40) per panel face; shoji (障子, translucent sliding screens) run roughly JPY 3,000–6,000 (approx. $20–$40) per panel.

For a six-mat washitsu held over 15 years, budgeting two resurfacing cycles plus fusuma and shoji re-papering yields an estimated total maintenance cost of roughly JPY 80,000–150,000 (approx. $533–$1,000). Flooring, by contrast, requires almost no maintenance over the same 15-year window. That said, tatami work can be scheduled during vacancy periods following tenant move-out, which means the cash outlay does not necessarily extend vacancy time.

Washitsu Renovation Cost and Payback Period (Conversion to Flooring)

Converting a six-mat washitsu to a Western-style room — including subfloor repair — typically runs JPY 150,000–300,000 (approx. $1,000–$2,000) (verify with local contractors). Solid wood flooring pushes the figure toward the higher end. For more on flooring selection, see our piece on why solid wood flooring adds value in rental properties.

Payback is assessed by combining the rent increase post-conversion with any reduction in vacancy period. If conversion raises monthly rent by JPY 3,000 and the upfront cost is JPY 200,000 (approx. $1,333), simple arithmetic gives a payback of roughly 5.5 years. However, the simultaneous risk of losing tenants who specifically wanted a washitsu must be factored in. At INA&Associates, every investment decision of this type is accompanied by a simple NPV model that lines up projected rent, vacancy periods, and 15-year cumulative maintenance costs for both scenarios. We evaluate net cash over the full lifecycle — not just surface yield.

Cost Allocation Under the 2023 Revised Genjō-kaifuku Guideline

The MLIT Guideline on Disputes Concerning Restoration to Original Condition (Revised Edition) maintains the principle that ordinary wear and deterioration of tatami surfaces, fusuma paper, and shoji paper is the landlord's responsibility. Tenant liability is limited to damage caused by intentional acts, negligence, or use beyond what is considered normal.

In practice, billing tenants a blanket "full tatami replacement fee" at move-out is a departure from guideline principles. The portion attributable to age-related wear must be separated out. Tenants can only be charged for damage that exceeds normal wear — cigarette burns, pet soiling, dragging furniture. The 2023 revision reinforces a mat-by-mat approach: where only certain mats are damaged, charge only for those. For a deeper look at monetizing older washitsu properties, see our article on turning vintage Japanese-room properties into high-yield assets.

Rent Impact Simulation

In recent cases we have handled, converting a washitsu in a central Tokyo studio building produced roughly 1.4× the number of viewing requests and a monthly rent increase of JPY 3,000–5,000 (approx. $20–$33) (individual, anonymized cases). Conversely, in a suburban family property, simply replacing the tatami — without any structural conversion — was enough to close the deal. The right call depends entirely on location and target tenant. For available renovation subsidies, also refer to our apartment renovation subsidy guide.

4. Designing an Attractive Wa-Modern Interior

Avoiding the "awkward East-meets-West" look requires consistent decisions across three layers: materials, color, and light.

Spatial Composition (Wall, Ceiling, and Floor Material Selection)

For walls, choose diatomite plaster (珪藻土), juraku-style finish (聚楽風塗装, a traditional Kyoto earth-clay plaster look), or washi wallpaper — all of which have a deliberately warmer color temperature than the bright white typical of Western-room wallboard. For the ceiling, either a sukashi (目透かし, spaced-board) ceiling or a soft off-white painted finish works. Tatami edging — its presence, absence, and color — determines much of the room's overall impression.

Furniture and Color Layering

The key to a cohesive wa-modern scheme is limiting saturation to three tiers. Across the three layers — floor (tatami), walls, and furniture — keep saturation differences small while allowing larger value (lightness) contrasts. Choose low-profile furniture as the default; lowering the eye line brings out the texture of the tatami. Limit accent colors to one, introduced through movable items such as cushions or a single-stem vase. Placing high-saturation colors in fixed elements makes it impossible to refresh the space with the seasons.

Lighting Design (Color Temperature and Distribution)

A color temperature of around 2,700 K (warm white / incandescent tone) is the standard choice. JIS Z 9110 (Japanese Industrial Standard for lighting design; 照明基準総則) places general living-room illumination at roughly 30–75 lux; a washitsu sits toward the lower end of that range to create a composed, settled atmosphere. Rather than a single ceiling fixture, a multi-source plan — a pendant combined with a floor lamp — introduces shadow and depth that a single ceiling light cannot produce.

Ko-Agari and Tatami Corner Dimensions

The height of a ko-agari (小上がり, raised tatami platform) changes its function: 30 cm feels like a gentle step up, with shallow drawer storage; 40 cm is the most comfortable for sitting on the edge and offers a good balance of storage capacity and ease of access; 60 cm maximizes storage but is not suitable for elderly residents who have difficulty stepping up and down. When we are involved in the construction process, we default to 40 cm and adjust based on the client's household composition. For floor area, 4.5 tatami mats (approximately 7.4 m²) is the practical minimum for a tatami corner — anything smaller struggles to accommodate sitting and lying down comfortably. Six mats (approx. 9.9 m²) gives more freedom for furniture placement.

5. Failure Cases and How to Avoid Them (Based on INA&Associates Cases)

Designs that look elegant on paper sometimes fall apart in the field. Here are real patterns we have encountered, shared in anonymized form.

The Classic "Awkward Hybrid" Pattern

A recurring renovation mistake is selecting a Japanese-patterned wallpaper for a washitsu that connects to the living room, while leaving everything else in standard Western-room finishes. A washitsu context only reads as coherent when at least two of the three key elements — tatami, sliding doors (fusuma or shoji), and wall finish — are treated in a Japanese register. Changing only one produces a result that reads as cheap rather than curated.

Tatami Selection Errors (Edging, Size, and Material)

Edgeless tatami (縁なし畳, Ryukyu-style) is popular in wa-modern schemes, but sizing standards differ by region, and without precise field measurements, the mats will not fit flush against existing floor framing (框, kashira). Skipping site measurements before ordering almost always results in visible gaps after delivery.

Inadequate Daylighting Leading to a Gloomy Result

A washitsu relies on the soft, diffused light that passes through shoji screens. North-facing rooms or properties with adjacent buildings close to the windows often suffer from chronic underlit conditions. The remedy is either resin shoji panels (ワーロン等) combined with indirect lighting, or routing natural light through a ranma (欄間, transom window above the sliding door). Indirect lighting aimed downward from the upper wall highlights the weave texture of the tatami and adds visual depth. Leaving a fluorescent tube ceiling fixture in place while pursuing a wa-modern aesthetic will make the space look inexpensive — the quality of light simply does not match the intention.

Restoration-Cost Disputes at Move-Out

We have taken over management of multiple properties where a previous owner billed tenants for full tatami replacement at move-out and ended up in a formal dispute. Under the Genjō-kaifuku Guideline, age-related deterioration is the landlord's responsibility. Without a properly documented breakdown separating ordinary wear from tenant-caused damage — anchored in the lease terms and the length of the tenancy — these disputes can escalate to small-claims proceedings. When we take over management, we invariably audit the move-in condition photos and verify that any special clauses are consistent with those photos and with guideline requirements. For a special clause shifting restoration costs to the tenant to be enforceable, it must satisfy three conditions: the clause was explained to the tenant, the tenant gave informed consent, and the cost being shifted is reasonable and beyond ordinary wear. A boilerplate clause without these three elements will not hold up.

6. Practical Maintenance for Washitsu

Once you understand the costs and effort involved, a washitsu is far less intimidating to manage.

Annual Tatami Care Schedule

Day-to-day care means dry wiping — no wet mops. Once or twice a year on a dry day, stand the mats on their edges and let them air in the shade. Concentrating dehumidifier use immediately after the rainy season ends reduces the incidence of mites and mold significantly. The standard cycle is resurfacing every 6–8 years and full replacement every 15 years. In rental operations, check mat condition at every move-out and decide on resurfacing, partial replacement, or full replacement based on actual condition. Imposing a rule like "replace everything after X years" regardless of condition tends to generate unnecessary expenditure.

Fusuma and Shoji Re-Papering: DIY vs. Contractor

Fusuma can be re-papered by a capable DIYer, but shoji frames frequently need straightening before paper can be applied cleanly, making professional work the safer choice. Comparing natural washi shoji to resin shoji (products such as Warlon): resin costs 1.5–2× more upfront but lasts 3–5× longer and is dramatically more resistant to tearing in households with children or pets.

Managing Washitsu in Homes with Pets or Young Children

Washi tatami or resin tatami (synthetic surface mats) significantly outperforms natural igusa against claw marks and pet accidents. Surface hardness is noticeably higher than natural rush, making these mats well-suited for long-term rental use. They resist fading, and restoration costs at move-out are meaningfully lower. The upfront premium over natural igusa is roughly 1.3–1.7×, but over a 6–8-year service life the additional cost is readily recouped. At INA&Associates, washi tatami has become our standard specification for pet-friendly properties.

7. Frequently Asked Questions

Q. Can I place a bed on tatami? A. Yes, but use load-distributing plates under the legs. Indentations from bed legs can be classified as damage beyond ordinary wear at move-out, potentially making the tenant liable.

Q. Does a washitsu reduce a property's sale value? A. For owner-occupied family homes, the effect is broadly neutral. For investment studio units, it tends to be a mild negative. Buyer segment is the determining factor.

Q. Is a washitsu dangerous for young children? A. If anything, tatami is superior at absorbing impact from falls. Exercise caution with open flames near the tatami surface.

Q. Is a washitsu a liability in a pet-friendly rental? A. Natural igusa is vulnerable to claw marks. Switching to washi or resin tatami eliminates most of that risk.

Q. How much does it cost to convert a six-mat washitsu to a Western-style room? A. Including subfloor work, JPY 150,000–300,000 (approx. $1,000–$2,000) is the typical range (verify locally). Flooring grade will move the figure up or down.

Q. Can a genuine washitsu be created inside a condominium? A. Subfloor depth and ceiling height are constraints, but thin tatami mats combined with a simplified shin-kabe (真壁, post-and-beam style) wall finish can convincingly evoke the aesthetic.

Q. Can I achieve a Japanese atmosphere without an actual washitsu? A. Placed tatami tiles, washi pendant lighting, and low-seat furniture together create a "Japanese ambience" without permanent structural work — an option well-suited to rental properties.

Q. How can a tenant protect tatami during a tenancy to keep restoration costs down? A. Interlocking foam tiles or a thin rug prevent surface abrasion. However, blocking airflow beneath a covering causes mold on the underside of the mat, so lift and air the covering regularly.

Citations and References

MLIT, "Housing Market Trends Survey" https://www.mlit.go.jp/statistics/details/jutaku_list.html
MLIT, "Guideline on Disputes Concerning Restoration to Original Condition (Revised Edition)" https://www.mlit.go.jp/jutakukentiku/house/torikumi/honbun2.pdf
MIC, "Housing and Land Survey" https://www.stat.go.jp/data/jyutaku/
NARO (National Agriculture and Food Research Organization) https://www.naro.go.jp/
BRI (Building Research Institute) https://www.kenken.go.jp/
J-STAGE (Architectural Institute of Japan and related journals) https://www.jstage.jst.go.jp/
Japan Tourism Agency, "Survey on Consumption Trends of Inbound Visitors" https://www.mlit.go.jp/kankocho/

Supervised by: Daisuke Inazawa (Licensed Real Estate Transaction Specialist / Certified Rental Property Manager / Representative Director, INA&Associates Inc.)