For any property, electrical renovation, whether partial or complete, is a critical aspect of the overall renovation. It ultimately determines the capacity of the electrical network to handle various appliances, such as electric ovens, induction hobs, electric heaters, air conditioning units, and electric vehicle chargers.
I often see how a lack of foresight and practical advice from electricians can lead to unexpected additional work and costs for homeowners, especially years later, when they would like to install new electrical appliances.
This guide offers insights into the phases of electrical installation, what to consider, and how to plan to cost-effectively realize all your future needs.
Electrical Renovations by Type
Full Electrical Renovation of Apartments and Condominiums
This type of renovation typically involves less extensive work and more limited options. For instance, installing an outdoor unit, whether a camera or larger equipment, requires permission from the residents' association. In very old condominiums, expanding the power capacity might also be restricted due to an outdated electrical network, although in my experience, this is now quite rare. In such cases, renovating the condominium's electrical network becomes necessary.
Single-Family House Electrical Installation
Installing the electrical system in a single-family house offers the greatest possibilities, making early planning for electrical equipment crucial. Failing to lay the groundwork at the beginning can lead to significant costs and even demolition work later on, which is undesirable, especially for well-equipped kitchens or beautifully designed gardens.
Typically, important considerations for single-family houses include, but are not limited to: solar panel preparation, electric vehicle charger installation, outdoor lighting, intercom systems, electric gates, garden storage or garages, garden lighting, and garden sprinkler or irrigation systems and pumps.
Panel Apartment Electrical Installation
Panel and apartment electrical installations share some similarities, but a significant difference exists: in panel apartments, general dismantling or wall chasing is not permitted, and grooves can only be cut vertically, not horizontally. Additionally, drilling or carving certain walls in panel apartments requires a structural stability permit.
Power expansion may also necessitate careful planning. We usually address cable and wire placement in two ways: one involves creating a plasterboard ceiling, allowing all covered cables to run above it. The other option utilizes floor skirting boards and stucco moldings designed to accommodate cables. While this approach has dimensional limitations, there are fortunately many adaptable solutions available.
During my electrician work, I've surprisingly found that some solutions considered standard in the industry fail to stand the test of time, even in relatively new, 8-10 year old houses. Drawing on this practical experience, I build systems for which I can confidently provide 10-year guarantee.
Below, you can gain insight into the implementation process, accompanied by practical tips presented without technical jargon.
Electrical Design and Installation Work Phases
1) On-site Inspection, Consultation, Joint Planning
The initial step in electrical installation work is the inspection of the site and joint planning. This involves – if an electrical design plan isn't already completed – reviewing the property collaboratively and discussing the desired electrical equipment. With over a decade of experience, we've encountered numerous solutions and needs.
Consequently, we'll ask many questions and offer practical suggestions at this stage, addressing points that might not initially come to mind. It's crucial to clarify all usage areas from the outset, as this forms the basis for circuit construction and the sizing of wires, the electrical network, and the small distribution board, also known as circuit breaker box.
While not exhaustive, here are some considerations when renovating and planning your electrical network:
- Location and function of switches and sockets
- Where do we want to switch on lights – from one or multiple locations?
- Should sockets be childproof? This is advisable for lower sockets but unnecessary for higher ones, such as those for cooker hoods.
- Where will the doorbell be located?
- Where will we work, and might we need multiple sockets for a laptop, printer, scanner, or router simultaneously?
- Where will the washing machine be, and will there be an electrically heated towel rail?
- Will there be electric heating? Even if not currently planned, it's worth considering, as even modern gas appliances often have a digital display and heating control unit requiring a power source.
- Lighting
- What types of lighting fixtures will provide the appropriate amount of light? Consider ceiling lights, spotlights, reading lights, and ambient/mood lighting.
- Will there be an LED strip? Where will it be powered? It's beneficial to plan the high and low current power supply separately in advance, as LED strips require a power supply (often called a transformer) that occupies space. Early consideration prevents ending up with an unsuitable placement at the renovation's end. A typical example is kitchen counter LED lighting.
- Will the lighting or LEDs be dimmable or of fixed brightness? This is important to decide early for switch and control design.
- Kitchen
- Location and size of the extractor hood?
- Power requirements of the electric hob and oven: is it necessary to install a 3-phase connection during the electrical network renovation?
- Where will the kitchen counter be? Numerous appliances here may require power, such as kettles, toasters, coffee makers, food processors, and blenders.
- Will there be a dishwasher, and where?
- Bathroom and restroom
- Toilet and bathroom fans: consider automatic operation, noise level, size, and design.
- Shaver and hairdryer sockets.
- Towel dryer socket.
- Spotlights, LED lights, and potential mood lighting.
- Jacuzzi or sauna.
- Garage
- Power for DIY and garden tools operated from garage circuits, such as lawnmowers (consider current consumption).
- Possible 3-phase installation for specific high-power consumers.
- Electric vehicle charger.
- Electric garage door with remote control.
- Garden and outdoor space
- Outdoor and garden plinth lighting.
- Irrigation system.
- Electric gate and driveway.
- Pool.
- Low-voltage systems
- Alarm system.
- Intercom.
- Camera system.
- Home cinema, Hi-Fi, and other sound systems.
- Thermostat cable installation (this can also be 230V).
- Other building electricity elements:
- Solar panels: planning in advance avoids later dismantling of walls and roofs down to the circuit breaker box (small distribution board).
- Energy storage systems.
- H-tariff (for air conditioning and heat pumps).
- Electric shutters.
- Electric fireplace.
- Electric heating.
- Dryer.
- Fire protection systems.
- Television and computer – the latter may require at least five sockets at the workstation, as the computer itself, printer, monitor, scanner, and a potential router will already use these.
Practically anything is achievable, but it's vital that during the electrical network planning, appropriate wire outlets are placed where we intend to locate devices in the future, even if they are not currently in use.
2) Dismantling Old Fittings, Creating a Temporary Power Source, Marking the Cable Routes
The renovation of an electrical network in an existing house naturally starts with the professional dismantling of the old fittings. A common question is whether the old conduits and wires can be reused to save costs during the electrical installation work in the apartment. While it's a rare occurrence, practical experience shows that in most cases and parts of the house complete renovation and replacement of all wires is essential.
For safe and efficient work, we establish a temporary power source at the start of the electrical installation. This involves temporarily installing a miniature circuit breaker box with IP67 protection, meaning it's resistant to dust, solid materials, and water immersion.
Based on the design plans, the routes for conduits and wires are marked, along with the locations for the fitting boxes.
3) Groove and Socket Cutting
A significant part of the electrician's work is cutting grooves and socket recesses. While it might seem straightforward to a non-expert, it's a very time-consuming and physically demanding task, often being the most physically strenuous phase of a home electrical installation.
Practical experience shows that unexpected obstacles like water pipes, drains, and steel support beams are common surprises. Therefore, even the most meticulous planning doesn't guarantee a trouble-free process, but this is a natural aspect of the profession and construction.
4) Installation of Junction and Fitting Boxes, Installing Conduit Pipes
This stage is often one of the most visually significant elements of electrical installation, where homeowners see clear progress in the work.
At this point, conduit pipes are embedded in the wall or, in many garage and outdoor installations, run externally. Correct conduit pipe sizing during the design phase is crucial because it ensures the later installation of the proper amount and size of wires.
Of course, there are situations where conduit pipes aren't used, such as when ceiling depth limitations are significant. In such cases, MM wall cable, typically no more than 4 millimeters thick, is installed directly in the ceiling.
Conduit pipes and junction boxes are usually secured with gypsum or another quick-setting material, allowing the complete wiring process to begin immediately without delays for the electrician.
For cable duct installations, this involves fixing the ducts, then inserting the wires and attaching the duct covers.
5) Cutting and Inserting Wires, Connecting or Splicing Wires Together
To create all the circuits, we insert wires of the appropriate size and cross-section, and then the wire connections are completed.
Based on my experience, the vast majority of errors occur at the connections, which can lead to overheating. Therefore, in addition to correctly sizing the wires during the apartment's electrical system implementation, I strive to minimize the number of necessary connections.
A frequent question is whether old wires in existing conduit pipes, protective conduits can be replaced section by section during an electrical network renovation in an existing building. While theoretically possible, the condition of the conduit pipes, protective conduit might warrant a complete new installation due to maintenance needs or future expansions. Occasionally, old circuit wires may have already rotted within the conduit pipe, requiring the entire section to be removed and replaced.
Of course, there are situations where "saving" shorter sections is worthwhile. An example could be ceiling wiring where, due to the decoration and unique characteristics of the ceiling, we attempt to carefully remove the old wires and pull the new ones through the existing conduit pipes.
6) Installing and Connecting a Small Distribution Board
The small distribution board or circuit breaker box is the heart of the system, where all circuits converge. Correct sizing of the electrical system and the miniature circuit breakers are critical here, as it ensures safe and long-lasting operation.
For both single-family homes and apartments, during electrical installations, the existing power (amperage) might be insufficient for the entire system. This is usually identified during the initial meeting, inspecting the property. In such cases, it’s advisable to start the power expansion process with a registered electrician before any work begins, as it can take several months.
When connecting or replacing any small distribution board, it's crucial to not only select the appropriate miniature circuit breakers ("fuses") for the wire sizes and overall load but also to connect them professionally, which includes tightening them to the specified torque!
Manufacturers specify the required torque for their modules' screws to ensure the connection is neither too loose nor too tight. A loose connection can cause overheating due to poor contact, while an overtightened connection can damage the device's screws, leading to loosening over time and a faulty connection. An electrician shall use a special torque screwdriver for this purpose.
While not exhaustive, here are some tightening torques for moduls and brands commonly encountered during installing a small distribution board:
- Hager miniature circuit breakers: 2.8 Nm per terminal.
- Schneider Electric miniature circuit breakers: 2 Nm at the top or bottom. (Click the link to find this data after fully expanding the technical data section.)
- OBO V50 Surge protection: 4 Nm. (This "torque" parameter is listed on the third page of the linked catalog.)
Mandatory components of the small distribution board:
- Miniature circuit breakers (fuses)
- Residual current circuit breaker (RCD), also known as: FI relay or life safety relay
- Surge protection: Increasingly extreme weather and lightning strikes strongly justify installing effective protection for expensive devices like electric hobs, gas boilers, heat pumps, air conditioners, laptops, and TVs to dissipate and protect against potential voltage surges. This is significantly more cost-effective than replacing damaged equipment.
Optional components:
- Bell module
- Relays
- Smart home systems (If planned for the future, it's important to note this early in the design phase due to sizing considerations.)
- Phase indicator light, LED – especially recommended for 3-phase systems
- Main switch (worth installing if there are multiple circuit breakers, allowing the entire system to be de-energized with a single switch)
- Fire protection main switch (primarily relevant in apartment buildings or properties specifically intended for rental)
To conclude this stage of the electrical installation, the system is then powered up and tested in a trial run. During this phase, we typically perform measurements related to the electrical safety inspection, primarily testing the operation of the residual current circuit breaker.
Following these stages, there is a pause in the electrician's work to allow for cladding, repairs, and painting.
7) Installation of Electrical Fittings
The installation of electrical fittings, switches, sockets, light fixtures, and the connection of the electric stove or hob occurs in this final stage of electrical installation.
It's crucial that the connection of an electric stove or hob is performed only by a professional electrician. Without an invoice and official confirmation of the installation, the device's warranty will be void, and the manufacturer may withdraw it in case of unprofessional installation. For such a high-value appliance, it's not worth the risk.
After installing all switches, sockets, etc., the final testing and commissioning of the completed system takes place.
8) Electrical Safety Inspection, Measurements
Here, a comprehensive instrumental test of all electrical circuits is conducted, and the measurement results are provided in documented form. This inspection is mandatory for new constructions, as well as for rental and sale.
9) Preparation and Handover of Documentation
The final step of the complete implementation is the preparation of the complete documentation generated during the electrical installation, which includes, among other things:
- Electrical safety inspection measurement results and certificate of conformity
- Issuance of the Equipotential Bonding (EPB) declaration (mandatory for connecting the gas meter and commissioning the gas boiler)
- Handover of the maintenance and user manual
- Issuance of other related certificates and documentation (Small Distribution Board inspection report, CE certificate of conformity, etc.)
10) Maintenance
Maintaining existing electrical systems is important for both apartments and single-family homes. In addition to providing written instructions, we will also explain and demonstrate maintenance procedures in person, as practical experience enhances retention.
If you have any questions or would like to inquire about the expected costs, please feel free to contact us!