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[Renovation] Electrical construction and how to request an electrician [DIY renovation]
Hello everyone, this is DIY Renova.
We are currently skeleton renovating a detached house that is over 30 years old.While doing what you can do with DIY yourself, "electrical work" is an area that amateurs should not do.So, this time, while continuing to renovate our home, we have thoroughly compiled the construction items that we actually consulted and requested by the electrical appliance store to ensure that there are no missing parts.
We hope this will be helpful to those who have questions such as, "How much should I ask an electrical appliance store?", "How much should I do on my own?" or "What should I do now?"
If you're wondering "How much renovation or remodeling can I actually do on my own home?" or "Where should I even start?", please visit this page. If you're looking to learn more about specific renovation processes or construction details, don't miss this page as well!
So, here you go.
How much electrical work should I request?Drawing a line with DIY
In Japan, it is prohibited by the Electrician Act for those who are not qualified as electricians to carry out indoor wiring and construction around distribution boards.In other words, in principle, you will need to request a professional to do the following construction work:
- Replacement of distribution boards and change capacity (amperes)
- Expansion and relocation of outlets
- New dedicated circuits (induction, air conditioners, EV outlets, etc.)
- New lighting circuit installation and change
- Installing the ventilation fan (power connection)
- New power supply (for outdoor outlets and water heaters, etc.)
Even if you can do this by imitating these things, if a fire or electric shock occurs, there is a risk of damages being compensated as illegal construction.If you don't have a qualification, all you can do is DIY at most, set up existing extension cords, smart home appliances, and install a router.
Please also read the article below in connection.
List of actual construction items requested (author's experience)
1. Adding amperes to the distribution board
Old-fashioned 30A contracts are the norm for wooden houses that are over 30 years old.However, I am currently using induction cookers, dishwashers, and washing machines with dryers.Contract changes to 40A to 60A must be made..This requires an application to TEPCO, so you will need to consult with an electrical appliance store and request an application on your behalf.
In particular, distribution boards require a Class 1 electrician qualification rather than a Type 2 electrician, so I think almost everyone must ask a professional.
2. Expansion and relocation of outlets
- A place for home appliances that require special circuits such as refrigerators and washing machines
- Multiple outlets to work rooms and desks
- Outdoor waterproof outlet
The key is to determine the location in advance, taking into account the furniture layout you plan to use in the future.
3. New lighting and switches
- Number and placement of downlights
- Power source for indirect lighting
- Switch height and position
Considering usability, please also consult with us about a "three-way switch" that can be turned on and off in multiple locations.
4. Installing ventilation fans (shower unit, washbasin, toilet)
- Ventilation fans are installed in each waterway (shower unit, washroom, toilet)
- Instructions must be given to the position of the duct hole on the exterior wall before DIY installation.
- "Natural exhaust type that can be ventilated to some extent even during power outages" is also an option
5. Power supply wiring for gas water heaters
Even though it is called a gas water heater, it requires a power source to ignite and control, so it requires a waterproof outdoor power source.Don't forget to request this one too.
6. Inspection and replacement of existing wiring (electric leakage check)
In buildings that have been built for a long time, the covering often deteriorates.Risk of electricity leakage or firewill increase.Now that the structure is exposed,Check the health of existing wiring and replace all of the wires if there is a problem.It's safe to do!
7. Intercom removal (wi-fi type installation planned)
Wired intercoms will be removed as they will not be used in the future.Instead, I plan to add a Wi-Fi-enabled smart intercom afterwards, so I asked them to leave just the power supply.
8. LAN wiring (1-2 locations)
Basically, Wi-Fi is used, but wired LAN is stable in work rooms and NAS installation locations.We will also anticipate that the location of the router or repeater will be moved in the future.Now, just one or two places to pass the LAN cable inside the wall.That's a smart way.
*Please note that internet companies often do not handle LAN wiring, and later installations will result in a mall that will make your appearance worse.
9. Installing a fire alarm (visible alarm)
As it is legally mandatory, it must be installed in each room.For households with elderly people or hearing loss, consider the type that is notified with light and sound.
in particular,
Things to tell when contacting an electrical shop
By organizing the following information in writing or email, it will be easier to request a quote.
- Site address and contact information
- Construction progress (e.g. structure exposed during demolition)
- List of desired construction details
- Location of outdoor drilling and through-hole work (marking is required when installing DIY)
- Preferred visit date (suggestions for 2-3 days)
Frequently asked questions: The relationship between internet connections and electrical work
Many people probably wonder, "Isn't LAN wiring an internet company?"
The answer is "Internet contracts and connections can be made by internet companies, and indoor wiring can be made by electrical shops."
Many internet companies (such as en Hikari, NURO, Docomo Hikari, etc.) will handle the installation of fiber optic lines, but they are not compatible with LAN wiring and outlet ports in each room, or are expensive.
By completing LAN wiring along with electrical work, you won't undermine the aesthetic look and save on wiring construction costs.
Prepare before the meeting
Below is a summary of the things you should prepare in advance to ensure smooth on-site meetings with the electrical appliance store.
- The entire house floor plan (printing recommended): Preparation to allow direct writing of locations on site
- Planning of furniture and appliances: Refrigerator, washing machine, microwave, TV stand, desk, etc.
- Notes on the number and location of the desired outlets and lighting: It's fine to imagine a live activity line, even if it's rough
- Desired location for internet or LAN wiring: Please specify if you would like to install the router or wired work room if you would like to have a wired router installed.
- Notes on how to charge EVs and future solar power generation plans
- Desired location of ventilation fan and whether or not there is a through hole installed(Please let me know if you are going to install the exterior walls yourself.)
- Notes on areas where there are problems with existing wiring: burn marks, burnt odor, difficulty in the switch, etc.
- Write down the questions you want to ask in bullet pointsExample: "Do you need two outlets for the toilet?" "Where can I pull the 200V air conditioner?"
- Take photos of the site with your smartphone or camera: Also useful when you want to share via email or LINE
By preparing these in advance, you will be able to improve your estimate accuracy and prevent the risk of unnecessary construction and redoing.
Time to request electrical work
When to do electrical work, the cost, finish and work efficiency will vary greatly depending on when you order it.Especially when requiring a skeleton renovation or a complete renovation, it is ideal to request and consult with us at the following times:
- When the dismantling is finished and the structure is exposed(The pillars, studs, and attics can be seen)
- Just before reupholstering the roof and exterior walls, under construction(Easy to adjust the through holes of the exterior wall)
- Before installation of pipes and insulation materials(You can work before the wiring is hidden)
At this stage, you will find the following benefits:
- Shortest and optimized wiring routes: It doesn't even turn into a mold or exposed wiring later, and it's finished neatly.
- Easy to drill holes in exterior walls and ceilings:If you do it later, you may have to do twice as much work.
- Easy to adjust with other contractors (carpenters, water, gas).: It is less likely to interfere with construction work other than electricity, preventing problems
Conversely, if you request additional electrical work after blocking the wall, you may need to re-stick the cloth or re-install the ceiling.It is best to consult in the early stages of renovation..
A draft request letter for estimates when making a request
I got it!Reflecting the following contents:Final Email DescriptiveFinished:
Added/Reflected Points
- LAN wiring: Request for 1-2 additional locations (Wi-Fi is mainly for use in the future)
- Ventilation fan: In addition to the shower unit,Request to install in the bathroom and toilet
- Please consult if there is a ventilation system that can be used even in the event of a power outage.
- Additional installation of fire alarms (visible alarms) also requested
Drawing email to the electrical shop (final version)
Subject: Electrical work consultation, on-site confirmation and quote request (skeleton renovation of detached houses)
XX Electric
Thank you for your help.My name is XX (your own name).
Currently, a wooden detached house built in the year.Skeleton renovations underway.
Now regarding electrical workPlease check on-site and estimateI would like to contact you.
CurrentlyBuilding demolition workSo we plan to remove the roof and exterior walls from next week onwards.
*As the exterior wall construction is planned to be carried out by DIY,Pre-meeting about external through holes and wiring locationsI would like to do so.
■Consultation/Request Schedule:
- Adding amperes to the distribution board
- Plans to increase current contract capacity (e.g. 30A → 60A)
- Please contact us, including application to Tokyo Electric Power Company
- Expansion and relocation of outlets
- Consultation regarding expansion and change of placement in each room or outdoor area
- New lighting and switches
- I would like to discuss the location of the installation while the ceiling is open
- Installing ventilation fans (3 locations)
- I would like to install an electric ventilation fan in the shower unit, bathroom, and toilet
- I would like to ask if it is possible to handle such a mechanism that can operate even in the event of a power outage (e.g. manual opening and closing or natural ventilation).
- Power supply wiring for gas water heaters
- I would like to secure a dedicated circuit for gas water heaters that are scheduled to be installed outdoors.
- Check and replace existing wiring
- Because it is old,Check for leakage or deterioration and replace if necessaryI would like to ask you to
- Removing the intercom
- I would like to remove existing wired intercoms.
- I plan to install a Wi-Fi system myself in the future.
- Added LAN wiring (1-2 locations)
- Basically, Wi-Fi is used, but wired LAN can be used in work rooms, etc.Install one or two LAN lines and outletsI would like to ask you to
- Installing a fire alarm (visible alarm)
- There is no fire alarm inside, so please install it in an appropriate location.
- Future EV support (optional)
- We are currently considering laying wiring for a 200V circuit (if possible)
■ Site information and visit requests:
[Site address] 〒XXX-XXXX
XXX-cho, XX City, XX Prefecture
[Contact] 090-XXXX-XXXXX
[Construction status] Currently being demolished (structure and wiring visible)
[Preferred date of visit]
・First preference:
・Second-order:
・Third preference:
・(Please include the candidate dates on 2-3 days)
We apologize for the inconvenience, but we would appreciate your confirmation before replying to the dates you can visit.
We look forward to your cooperation.
XX (your name)
Email address: 〇〇〇〇〇
Phone number: 〇〇〇-〇〇〇〇-〇〇〇〇〇
Things to check during meetings
When you actually have an electrical shop in place, it is safe to check and consult with the following points.
- Uses of each room and the number of outlets and locations required(Taking into consideration the furniture arrangement)
- Types and number of lighting, and switch arrangement(3-way switch and dimming)
- Check the location of the ventilation fan and the location of the through holes inside the exterior wall
- Location of the distribution board and future expansion room (number of circuits)
- LAN wiring location and cable type (Cat6, etc.)
- The need to check the status of existing wiring and replace the deteriorated parts
- Preparation wiring for future installation of EV outlets and solar panels
- Location and type of fire alarm (light alarm, etc.)
- Prioritize what work should be done before ceilings or walls are closed
During the meeting, if possible, it will be easier to talk by writing directly on a "printed floor plan" or "photos for which construction is scheduled."
Conclusion: Find out what you can and can't do
How was the article?
Electrical work is closely related to "what is determined by law" and "what is related to safety."
Even though DIY renovations are a booming trend, the general rule is to ask a professional to do any construction work that could lead to fires, electric shocks, or accidents.
"How far is DIY, and where is the area of the electrician?"
"Where's the wiring you'll never have to worry about later if you do it now?"
Make sure to carefully identify these and work together with trusted companies.
The article below is relevant, so please try it if necessary.In addition,Click here for articles about electricityPlease try looking from.See you then!
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