Why this comparison matters in 2026
Nature-inspired textures and warm colours provide a timely starting point. Houzz reported that U.S. searches on its platform for "biophilic design" increased 112%, while "chocolate brown" rose 153%, comparing January-March 2026 with the same months in 2025. These are Houzz search trends, not Google keyword volumes or proof of demand for a particular cladding product. [1]
For a timber project, our design takeaway is to compare tactile black surfaces and warm grain-led finishes together. Then look beyond the mood board: what treatment has the wood received, how should it be detailed, and what appearance will the owner maintain?
What is Shou Sugi Ban?
The term is widely associated with Japanese-inspired charred timber. Traditional yakisugi uses sugi, commonly called Japanese cedar. Charring creates a dark surface, while subsequent brushing can expose more grain and produce a less heavily carbonised appearance. Modern specifications should identify the actual species, burning method, brushing level and coating rather than relying on the name alone. [2]
What is thermally modified wood?
Thermal modification is controlled heat treatment of the timber, rather than simply burning its face. Heat-and-steam processes can change moisture behaviour through the board, improving dimensional stability and resistance to biological degradation under the relevant treatment conditions. The exact result depends on the wood and process. [3][4]
ThermoWood is a registered trademark owned by the International ThermoWood Association. "Thermally modified wood" is the generic description; the two terms should not be used as automatic proof that any supplier belongs to the trademark programme. [3]
Shou Sugi Ban vs. thermally modified wood: at a glance
This is a process comparison, not a ranking of every commercial product. Product-specific technical data takes priority. [2][3][4][7][8][9]
Can wood be both thermally modified and charred?
Yes. Documented architectural applications use thermally modified timber with an additional charred surface. That means a black board might be surface-charred only, thermally modified and then charred, or made dark by another finishing process. [5][6]
Ask two separate questions: "Was the timber thermally modified through the board?" and "Was the face actually charred with flame?" Where both are specified, request the production sequence and an approved finished sample. A treatment combination should still be assessed as a finished product, not as an automatic addition of every claimed benefit.
Black cladding or warm timber: choosing the visual direction
For a high-contrast facade, consider dark vertical boards beside pale render, stone or a light entrance surround. For a softer composition, explore warm timber on a recessed entrance, soffit or screen. Using both colours in different building elements can keep the palette connected without making every surface identical. These are design options, not performance claims.
Do not use colour as a process certificate. Commercial charred-look products can be embossed and tinted without flame charring. That may meet a visual brief, but it is different from an instruction to supply genuinely flame-charred wood. Put that requirement into the quotation and sample approval. [6]
Maintenance: keeping the colour is a separate decision
Before choosing a finish, decide whether the project should retain its original colour or develop a weathered appearance. For charred siding, cleaning and any recoating should follow the specific manufacturer and coating instructions. Do not assume that every charred surface has the same maintenance schedule. [7]
For thermally modified cladding, untreated brown surfaces can gradually grey outdoors. Lunawood's May 2026 cladding care guide distinguishes this colour change from its product's stability and decay resistance, and recommends compatible surface treatment where brown colour retention is required. This distinction is useful when comparing products; another supplier's performance claims or care schedule should not be transferred automatically. [8]
For your chosen board, request a written cleaning method, approved maintenance coating and realistic inspection guidance for the actual exposure. Ask for weathered examples of the same species and finish, rather than relying only on a freshly produced sample.
Does charred or thermally modified wood mean fireproof?
No such conclusion follows from either treatment name. A 2026 study on treated beech and birch found differences in early flame spread, but the investigated modifications did not change the Euroclass-related classification in the reported small-flame assessment. That is a result for the tested specimens, not certification of other species, products or wall systems. [9]
Treat fire performance as a documentation question. Where a project has fire or bushfire requirements, ask the responsible designer or certifier to review evidence covering the proposed product and its intended installation. A photograph of a black surface is not that evidence.
Which option costs less? Compare the same specification
A useful quote comparison starts with a common brief, not a price attached to a broad product name. Ask each supplier to price the same species and grade, finished dimensions, profile, effective cover width, length mix and finish. List any thermal treatment and surface charring separately so the offers describe the same scope.
Then compare the total purchasing scope: usable coverage, allowed waste, finishing, trims, fixings, packing and the agreed delivery terms. Keep material price separate from installed cost. This approach makes a quotation more useful than an unsupported universal price per square metre.
Which should you specify?
Start with the process requirement. Choose a genuinely charred option when flame-created surface character is essential. Evaluate thermally modified timber when documented moisture-related stability is a priority. Discuss a combined specification when both are part of the brief. The final choice still needs to match the species, exposure, detailing, finish and maintenance plan. [2][3][5]
For procurement, we recommend approving a representative sample range, a profile drawing with effective cover width, a written process description and the relevant technical documents together. A beautiful sample is useful, but a sample plus a clear specification is easier to purchase consistently.
Frequently asked questions
Is Shou Sugi Ban just black-painted timber?
No. Genuine charred timber has a deliberately burned surface. Paint, stain and embossed charred-look finishes may produce a similar colour or texture, but they are not the same production method. Ask for a written process description. [2][6]
Can thermally modified wood also have a black charred finish?
Yes. Thermal modification and surface charring can be combined. Specify both when both are required; a black colour by itself does not establish either treatment. [5][6]
Does thermally modified wood stay brown outdoors?
Not necessarily. Without a suitable colour-retaining treatment, it can weather towards grey. Confirm the coating and maintenance guidance for the particular product. [8]
Which option is maintenance-free?
Do not assume either is universally maintenance-free. Separate the desired appearance from the material's technical performance, and follow the selected product's care instructions. [7][8]
What information makes a cladding quotation easier to compare?
Provide the project location, application, quantity, species preference, finished size, profile, cover width, length requirements and finish reference. Add any required test documentation and delivery terms before comparing offers.
Explore exterior timber options with MUMU DESIGN
MUMU DESIGN offers Shou Sugi Ban and thermally modified cladding options with custom dimensions, profiles and finishes. Send your drawings, project location, quantity and finish references to discuss a suitable product specification and sample options. [10]
Shou Sugi Ban cladding | thermally modified cladding | request a project quotation
The most useful question is not simply "black or brown?" It is "which wood, which process, which finish and which evidence fit this project?"
Sources and further reading
[1] Houzz Research. 2026 U.S. Houzz Emerging Summer Trends Report (20 May 2026).
[2] Nakamoto Forestry. About Yakisugi (Shou Sugi Ban).
[3] International ThermoWood Association. ThermoWood: process and trademark.
[4] Lunawood. Thermal Modification of Wood.
[5] Lunawood. Garth Private Residence: an example of charred thermally modified cladding.
[6] Thermory. Ignite: embossed and tinted thermally modified spruce.
[7] Nakamoto Forestry. Shou Sugi Ban Siding Maintenance.
[8] Lunawood. ThermoWood Cladding Maintenance and Care (May 2026).
[9] Cermak et al. Assessing the Fire and Thermal Behavior of Modified Beech and Birch Wood. BioResources 21(3), 2026.
[10] MUMU DESIGN. Shou Sugi Ban and thermally modified cladding product information.