Condo rules in Japan that affect furnishing and light renovation: a guide for foreign owners

Owners share the building

When you buy a condominium unit in Japan you own the unit and a share of everything else: the structure, the exterior, the corridors, the elevators and the shared pipes. MLIT's English booklet for foreign unit owners (March 2026) explains that owners are responsible for the common areas as well as their own unit, through the management association (kanri kumiai) of which every owner is a member.

MLIT's model bylaws draw the line between the two. Ceilings, floors and walls belong to your unit except for the parts that form the building's structure. For the front door, only the lock and the paint on the inside belong to you. Window frames and glass are not part of your unit (Article 7). Balconies, front doors and windows are common parts that you have the exclusive right to use (Article 14). The structural floor slab, the shared vertical pipes and the pipe spaces are common parts too (Exhibit 2).

The bylaws and where to read them

Each building has its own bylaws (kanri kiyaku), and MLIT's booklet calls them the highest rules of the building. They apply to owners and tenants. Most are based on MLIT's Standard Condominium Management Bylaws, last revised on 17 October 2025. In April 2026 the Condominium Management Center published a provisional English translation of the model, which it notes is not an official translation.

The model leaves detailed rules for using the building to separate use regulations (Article 18). Ask whether rules on work hours, deliveries and application forms are set there. Ask the management company for both documents, and for the application form itself. Your building's rules may differ from the model, so the model is a guide to the questions to ask and your own documents give the answers.

What usually needs the board's approval

Under Article 17 of the model, if you plan to repair or remodel your unit, or attach or replace fixtures, in a way that may affect the common parts or other units, you apply to the president of the association and receive approval in advance. The application includes design drawings, specifications and a work schedule. The board decides by resolution, the president or a person they appoint may inspect the work, and if the work later affects the common parts or other units, the owner who ordered it puts it right at their own cost.

MLIT's commentary on Article 17 gives examples of work that needs approval:

• New flooring
• Installing a prefabricated bathroom unit
• Air conditioning fixed directly to the main structure
• Fitting or replacing branch pipes and wiring
• Changing the layout of rooms

Flooring and sound ratings

Flooring affects neighbours directly, because footsteps carry to the unit below. MLIT's guidance for approving work (Attachment 2 to the commentary) says the condition for replacing floor finishes is to confirm sound insulation equal to or better than when the building was new. It adds that the effect of flooring depends on the structure, the method and the materials, so an expert should check it.

The guidance gives two examples. In a building that had wooden flooring from new, the board checks that the new flooring's sound rating is at least the original one and that it is laid as the manufacturer's catalogue specifies. In an older building that had carpet from new and has a thin slab, the board may set a minimum sound rating as a condition. The required rating is decided building by building. We could not find an official English explanation of these ratings, so ask the management company for the required value in writing and give it to your contractor before choosing a floor.

Windows, doors, balconies and the structure

Because windows and front doors are common parts, the model makes the association responsible for improving them as part of planned repairs (Article 22). If the association cannot do this in time, an owner may do the work at their own cost with approval. MLIT's guidance says the board checks colour, shape, position and any loss of security or sound insulation.

Fixing things to a balcony outside the places set aside for them, such as an air-conditioning outdoor unit, needs approval, and the board checks for obstruction of evacuation routes, damage to waterproofing and bolts driven into the structure. Drilling into the structural concrete or driving in anchor bolts also needs approval. This matters for furnishing too: before fixing shelves or tall cabinets to a wall, ask whether that wall is structural.

Work hours, neighbours and notices

Work that does not need approval may still need a notice. Article 17(7) of the model asks owners to notify the president in advance of work during which contractors enter the building, materials are carried in, or noise, vibration or smells may reach others. MLIT's guidance suggests that the notice states the work hours, the content of the work and the contractor's name, and that work causing noise or vibration is announced to other residents, for example on a notice board.

MLIT's booklet also stresses that a quiet home is highly valued in Japanese condominiums and that noise can damage relations with neighbours. Agree the working days and hours with your contractor before you apply, and keep to them.

This is general information only. For your own building, ask its management company, a licensed architect, or the relevant office.

What furnishing alone does not need

MLIT's guidance gives examples of work that needs neither approval nor notice because it has no effect on others, such as changing a light bulb, a tap washer, a shower head or a heated toilet seat. Choosing and placing freestanding furniture, rugs, lamps and art is not building work and falls outside Article 17. Delivering it may still be covered by your building's use regulations, so ask about notice, hours and elevator protection before the first delivery.

If you live abroad, MLIT's booklet notes that from April 2026 you can appoint a domestic manager with an address in Japan to act for you in the association, for example to vote at general meetings and pay management fees. Ask the management company how they accept applications and notices from an owner overseas.