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What is a changeover? Understanding Layout Changes: From Processes and Costs to Important Considerations

2026-08-09

What is a custom interior design? Do I need a custom interior design? To what extent can a custom interior design be done on a pre-sale apartment? What are some things to keep in mind? This custom interior design guide will explain everything for you, including the meaning, projects, process, and costs of custom interior design. Master the key points of custom interior design so that even if you don't know where to start, you can create the ideal layout for your future home.

What does "客变" mean?

The full name of "customer change" is "customer modification". When building a pre-sale house, the developer will pre-configure the standard layout, flooring material and basic equipment. However, when the project progresses to the point where the structure is completed and before the interior decoration work such as partition wall construction and water and electricity piping is about to begin, the developer will send a letter to the homeowner who has signed a contract, asking them to submit a request for design changes within a specific period of time to adjust their new home to the way they envision it.

In addition, the notification time and application period for customer changes will vary depending on the construction progress and regulations of each construction company, and are not the same for all projects.

Why Custom Interior Design? Three Major Benefits at a Glance

In the past, when buying a traditional completed house, if one was dissatisfied with the layout, they faced the predicament of "demolishing and rebuilding" after taking possession, which not only wasted time but also incurred expensive demolition and cleanup costs. What are the benefits of choosing to buy a pre-sale house and customize the design?

Benefit 1: Saves on future demolition and rework costs.

If you find that the layout is unsuitable after taking possession of the property and want to change the partitions or water and electricity systems, you must first demolish the walls, remove the waste materials, and then redo the masonry and piping. The process is complicated and the cost will be several times higher than adjusting directly during the customer renovation stage.

Benefit 2 of the customer-oriented layout: The layout truly fits the lifestyle.

Every family has a different member structure and lifestyle. By changing the layout of a pre-sale home, you can make the space suit your daily life in advance.

Whether you're a baking enthusiast who needs a spacious open kitchen; a thoughtful family who likes to stock up on a lot of food and wants to plan a separate storage room for your mother; an audio-visual enthusiast who wants to install concealed pipes during the construction phase to create an invisible surround sound theater without exposed wires; or even a three-generation family living together who wants to widen door frames and ensure barrier-free movement, all these needs can be met before the building is completed.

Benefit 3 of customer conversion: Shortens the subsequent decoration construction period

The core value of custom-made houses lies in making customized adjustments during the unfinished stage. The condition of the house at the time of handover can be described as a "semi-finished product," allowing the interior design team that comes in later to directly enter the formal stage of woodwork and system cabinets, shortening the waiting time before moving in.

What does the customer-side transformer require modification? What are some common customer-side transformer projects?

(I) Four major categories of interior passenger space design

Customer modifications are not about blindly making large-scale changes without any restrictions; they can be mainly divided into the following four core projects:

1. Change in pattern

The position and size of non-structural partition walls can be adjusted. For example, two small rooms can be combined to create a large master bedroom, an unused storage room can be converted into a dressing room or study, the opening direction of doors can be adjusted, or a wall can be removed to make the public area more spacious. As long as load-bearing walls, shear walls, or the main structure of the building are not affected, most interior walls can be freely adjusted.

2. Water and electricity pipeline and socket configuration

Based on the future placement of furniture and equipment, the locations of sockets, air conditioning drain outlets, double-switch switches, etc., will be replanned, and the low-voltage configurations such as telephone lines and network lines will be located simultaneously.

As modern families have higher demands for technology and convenience in their lives, they often install USB sockets on both sides of the bed, reserve independent power supplies for bidet toilets and dedicated sockets for electronic wardrobes in the entryway, and plan in advance for the drainage system required for automatic dishwashers.

3. Return and exchange of building materials and equipment

If the kitchen appliances, imported bathroom fixtures, or even the floor tiles provided by the building contractor do not match your expected design style (such as: micro-cement milk tea style, Japanese wabi style), you can apply for a refund from the contractor during the customer change period, get the materials back with a deduction, and then purchase and install other materials according to your preferred style.

However, it's important to note that developers typically offer "materials and labor included" quotes, meaning that in case of changes, they usually only refund the cost of materials, not the installation wages. Furthermore, the "wholesale price" from developers' bulk purchases is often much lower than the market retail price, so a full refund doesn't necessarily save you money. For example, if the contract states an 80,000 NTD refund for kitchen appliances, but the market price for the same quality appliances is 120,000 NTD, you'll have to absorb the 40,000 NTD difference yourself.

4. Changes in flooring materials and paint coatings

If you want to change the flooring material in the living room, dining room, and bedroom, or apply to the builder to leave some walls unpainted in the standard lily white color and keep them in their original plaster state so that special paint or wallpaper can be applied directly later, these are all within the scope of the client's contract.

(II) Common Modification Items for Passenger Transformers

Partition Project

Adding or removing partition walls
Adjust door position and opening direction
Adjust wall length and thickness

Water and electricity configuration

Adjust the position and number of sockets and switches
Planning for low-voltage electrical configurations such as television, internet, and telephone.
Reserve locations for air conditioning power supply, refrigerant pipes, and drainage.

Lighting configuration

Change the type of lighting fixture (e.g., convert ceiling lights to track lights).
Adjusting the position of the lights, switch control, and circuit configuration

Water supply and drainage engineering

Adjust the positions of the kitchen sink, gas stove, and dishwasher.
Plan the location of bathroom drainage, bidet toilet sockets and equipment.

Woodwork reservation

Plan ahead for the necessary electrical outlets and low-voltage wiring for wooden structures such as TV walls and display cabinets.
Reserve HDMI, network, power and other future usage needs

Customer change process in 4 steps, how to read the customer change diagram?

Customer Transformer Process 1: Receiving Customer Transformer Notification and Drawing Request

Developers typically notify homeowners 2-3 months before the project reaches a certain floor, informing them of the timeframe and application deadline for any modifications. At this time, homeowners should proactively request electronic plans from the developer as a basis for all subsequent modifications. The following are common documents to request:

Floor plan: Solid thick black lines represent structural load-bearing walls and columns, while hollow double lines represent non-structural lightweight partitions, which are adjustable within the customer's space.
Water and electricity pipeline and switch configuration diagram: The "S" on the diagram, along with the number or legend, indicates the switch location. Pay attention to whether the flow is convenient.
Outlet and low-voltage wiring configuration diagram: The diagram will have special symbols to mark the locations of low-voltage wiring holes such as network and telephone, which will determine the future location of TV wall, electronic devices, and desk area.
Floor tile and ceiling plan: Pay attention to the slope markings and drainage gradients in humid areas such as kitchens and bathrooms, as these will affect the waterproofing and drainage.
Building materials and equipment list: A detailed list of the brands, specifications and models of all flooring materials, kitchenware and bathroom fixtures.

The thickness, coloring, and symbol methods may vary slightly depending on the drawing specifications. Please refer to the legend in the annotations on the drawing for details.

Customer change process 2: Demand planning and customer change diagram drawing

Homeowners need to confirm the living needs and space usage habits of family members within the time limit and translate their layout ideas into professional custom design drawings. Since construction companies only recognize standard construction drawings, it is recommended to hire a designer at this stage to help produce custom design drawings that meet the standards, ensuring that the construction company can fully understand and construct according to the drawings.

Demand planning direction:

Resident planning: How many family members will live here now and in the future? Are there any needs such as newlyweds, newborns, pets, or elderly relatives living together, which will affect the number of rooms and space configuration?
Space usage requirements: Whether a study, work area, kitchen island, multi-functional room, or larger public space is needed, as a basis for adjusting the partitions.
Furniture and appliance configuration: Have the sizes and locations of large furniture, televisions, refrigerators, washing machines, etc., been determined to avoid affecting the planning of sockets, water and electricity, and traffic flow?
Equipment requirements: Whether to plan to install dishwashers, bidet toilets, dryers, air conditioners, etc., and to reserve drainage, power supply and pipelines in advance.
Storage needs: Whether additional storage space is needed in the entryway, kitchen, or bedroom, as a reference for cabinet and socket configuration.
Flexibility for future use: Consider whether there are future changes in family members or the addition of equipment, and make appropriate provisions for sockets, network holes and wiring to improve the flexibility of space use.

Notes on passenger diagram changes:

First, confirm the dimensions of the furniture and appliances, then plan the locations of sockets and equipment.
Reserve space for future needs, such as robot vacuum cleaners, smart home devices, projectors, etc.
Confirm that subsequent doors, cabinet doors, and drawers will not interfere with each other when opened.
All changes should include complete information, such as equipment specifications, height, distance, and relocation dimensions. For example, a new 110V double socket should be installed at a height of 300mm and a distance of 450mm from the right wall.
Pay attention to whether the air conditioner drainage, refrigerant pipes, and outdoor unit configuration meet the requirements.
Confirm the developer's and customer's specifications to avoid altering unmodifiable items such as structural walls, fire-fighting equipment, and main pipelines.

Customer change process 3: Submit to the construction company, participate in the customer change meeting and review the drawings.

After the designer officially submits the customer change drawings to the developer, the developer will first overlay and revise the internal construction drawings to confirm whether the changed partitions and water and electricity routes will conflict with the structural, fire protection, and other floor piping systems. After this step is completed, a "drawing review meeting" is usually arranged, in which the homeowner, designer, and developer's construction department check the contents of the drawings item by item, and sign and stamp them after confirming that there are no errors.

Customer renovation process 4: Finalize the plan and carry out construction, and conduct acceptance inspection before handover.

After the drawings are confirmed to be correct at the meeting, both parties sign the final customer change confirmation form or contract appendix. The developer will then carry out construction according to the drawings. The discussion at the customer change stage is now officially finalized, and the next step is to wait for completion and handover of the property.

During acceptance, it is recommended to prepare the finalized drawings from the drawing review meeting (either paper or electronic) and compare them item by item on-site.

How are passenger vehicle/transformer costs calculated?

Customer conversion costs are roughly divided into two parts: engineering costs on the construction side and planning service fees on the design side.

1. Customized design fees from design companies

If you choose to hire an interior design company, the fees are usually calculated based on the square footage or apartment type, or you can sign a comprehensive interior design contract that includes the renovation costs. Although this is an expense, professional designers can accurately determine the height of electrical outlets and the safety of water and electricity circuits, avoiding oversights that homeowners might have when planning their own projects.

Priced based on actual area: approximately NT$2,000 to NT$5,000 per ping (3.3 square meters).
Priced according to apartment type: approximately NT$30,000 to NT$100,000 per unit.
Interior design contract: Subject to actual terms

2. Additional charges and deductions for construction projects by the developer.

The fees charged by the developer are calculated item by item according to the "Addition and Subtraction Details Sheet". As the name suggests, there is a charge for new projects and a refund for canceled projects. Unlike the service fee of the design company, this fee is paid directly to the developer and there is usually no room for negotiation.

Additional items: relocating switches, increasing the number of sockets, building more partition walls; the developer will charge for materials and construction fees.
Additional cost reduction: If you return the kitchenware or floor tiles provided by the developer, the developer will refund the material cost.

What are some things to keep in mind when dealing with customer-related issues? A compilation of frequently asked questions (FAQs).

Q1 What are some things to keep in mind when changing passenger-carrying equipment?

Although a customer conversion project may only involve "signing a drawing and attending a few meetings" for a short period of one or two months, it involves multiple aspects such as scope, costs, and contractual responsibilities. Below are four easily overlooked points to note:

Time is of the essence; opportunities are fleeting: client changes cannot be made at any time. Developers typically only open the window once, and the deadline is fixed. It is recommended that as soon as you receive a notification from the developer, you immediately confirm the deadline and begin planning your needs or contacting a designer for assistance as early as possible to avoid missing this unique opportunity for adjustment due to hesitation and indecision.

Obtaining complete drawings is crucial for accurate planning: precise changes to the layout and plumbing/electrical systems require a sound basis. It's recommended to request the original floor plan, the structural plan of the immediate floor above, electrical wiring diagrams, plumbing diagrams, and low-voltage wiring diagrams from the developer in CAD format. If a complete set isn't available, at least the building floor plan and plumbing/electrical plans are essential for planning discussions.

Avoid excessive client-mandated changes: While client-mandated changes offer greater flexibility, excessive and frequent changes can easily lead to additional costs, increase construction complexity, and even result in rejection by the developer, potentially delaying the overall project schedule. It is recommended to clearly define long-term living needs and submit them all at once.

If public safety regulations are involved, the developer has the right to refuse to make changes:

The following items are crucial to the fire safety inspection and building regulations of the entire building and are considered "absolutely forbidden" for customer-transformed vehicles:

The path and outlet location of the kitchen exhaust duct are crucial in determining whether the emission of cooking fumes will affect neighbors or violate building codes.
Extending balconies alters the original building and escape routes, and is generally considered illegal construction in Taiwan; therefore, applications are never accepted at this stage.
The location and quantity of fire-fighting equipment such as sprinklers and smoke detectors are mandatory according to fire protection regulations. They are crucial to the public safety and fire safety acceptance of the entire building and cannot be arbitrarily adjusted.

Confirm every detail of the contract and leave no room for ambiguity regarding liability: all increases or decreases in costs, scope of work, and whether returned materials will be refunded along with wages should be clearly stated in the contract or in the billing details to protect your rights.

Q2 Can a newly built house be converted into a rental property?

Custom renovation is a mechanism specific to pre-sale homes. Newly built homes, on the other hand, are already completed, with partitions, plumbing, electrical systems, and building materials all fixed, so the same customer renovation process cannot be applied to pre-sale homes. If you purchase a newly built home and want to adjust the layout or equipment, you must return to the logic of general interior design, achieving your ideal layout through wall knocking, demolition, and rewiring.

Interior design for clients should not be a mistake.BSTUDIO Tailor-made for your destined home

While a custom substation may seem like a cost-saving tool, it involves complex building structures, intricate plumbing and electrical configurations, and intricate blueprints. Homeowners who attempt to install it themselves often overlook crucial details and may even find themselves at a disadvantage when comparing blueprints with those of the builder or construction company.

If you are about to enter the renovation phase, or have already received a notification from the builder but don't know where to start, the BSTUDIO interior design team can accompany you to review the drawings, take stock of your living needs, assist in assessing the feasibility of layout changes, and grasp the key details of water and electricity planning, laying the most solid foundation for future decoration.

BSTUDIO Advantages:

Background of integrated architecture and interior design: B-Studio's core team is led by architects, and its services span architectural design, interior design, self-built projects, and urban renewal, and can assist in interpretation from an architectural perspective.
Aesthetics and Craftsmanship Quality Recognized: B-Studio has won numerous international design awards and can help plan a home that balances layout, flow, and spatial aesthetics.
The "Heaven, Earth, and Man" design concept starts from the essence of life, understanding the lifestyles and long-term needs of the residents, and then working backward to determine how the layout and pipelines should be adjusted.
Extensive experience in exposed concrete and Japanese minimalist style: Proficient in exposed concrete architecture and Japanese minimalist design, suitable for interior design styles that lean towards minimalism, wabi-sabi, and natural materials.

Don't let the developer's blueprints limit your imagination of your home. Let a professional designer plan ahead for your future new home!

Contact BSTUDIO for passenger transformation planning