What is First Fixing Electrics?
First Fix Electrics in Detail.
Rita Cani
4/7/20255 min read


First Fix Electrics.
If you’re building or renovating a home, you might hear the term “first fix electrics” thrown around. It’s a key part of the electrical installation process, but what does it actually mean? And what’s the difference between the first and second fix?
Whether you’re a homeowner preparing for a renovation, a budding electrician, or just curious about how homes get their electrics installed, this blog post is here to break everything down in a clear and simple way. Let’s dive into the world of first fix electrics and why it’s such a crucial step in any building or refurbishment project.
What is First Fixing Electrics?
First fixing electrics is the stage in an electrical installation when all the cables, wires, and electrical back boxes are put in place. It happens before the walls are plastered and before any carpets, furniture, or fixtures are installed.
Imagine your house is like a skeleton at this stage. The floors may be bare, and the walls are often just timber frames or bare brick. This makes it the perfect time for electricians to hide all the wiring and make sure that everything is in the right place.
The first fix includes things like:
Running cables through walls, ceilings, and floors
Installing electrical back boxes where switches and sockets will go
Laying the groundwork for built-in lighting, extractor fans, and appliances
Planning and positioning wiring for things like internet, TV, and security systems
In simple terms, the first fix is all about getting the invisible parts of your electrics into place — the bits that need to be hidden inside walls or under floors.
What is the Second Fix?
Now that you know what the first fix is, you might be wondering what comes next. That would be the second fix.
Second fix electrics is the stage where everything becomes visible. After the plastering is done, and the walls are painted or decorated, electricians return to fit all the visible parts of the electrical system.
This includes:
Installing switches and sockets onto the back boxes
Connecting light fittings and pendant lights
Wiring up built-in ovens, hobs, and extractor fans
Fitting cover plates and testing everything to make sure it works safely
In short, the second fix brings the electrical system to life. It’s the final stage where you start to see everything take shape — the lights turn on, the plugs work, and your home starts to feel complete.
Why is First Fix So Important?
The first fix stage might not be the most glamorous part of a renovation — there’s no shiny new sockets or beautiful light fixtures just yet. But it’s incredibly important for a few reasons:
1. Planning and Precision
During the first fix, electricians work closely with builders, plumbers, and homeowners to plan exactly where every light, switch, and socket should go. Get it wrong, and you could end up with a socket hidden behind a wardrobe or a light switch in an awkward place.
2. Hiding Wires
The first fix is the best time to hide all the messy stuff — cables, conduits, and wiring for things like speakers or alarms. If you wait too long, you’ll need to cut into finished walls or floors to add new wiring, which can be expensive and time-consuming.
3. Safety
Good electrical work during the first fix lays the foundation for a safe home. All wiring must meet legal regulations and building standards. Poor wiring can lead to serious issues, including electrical fires.
What Happens During First Fix Electrics?
Let’s take a closer look at what actually happens during a typical first fix:
1. Site Preparation
Before the electricians start work, the site needs to be ready. That usually means the walls are still open, and there’s no plaster, paint, or flooring in the way. Sometimes, floorboards may be lifted or temporary scaffolding put in place.
2. Cable Routing
Electricians start by routing cables through the property. This could involve drilling holes through studs, notching joists, and running cables between floors. Every wire is positioned based on a carefully planned electrical layout.
3. Installing Back Boxes
Once the cables are in place, electricians install back boxes — small metal or plastic containers that sit in the wall. These will later hold your sockets and switches. Getting the height and position right is really important here.
4. Marking Positions
During the first fix, electricians mark where all fittings will go — light switches, ceiling lights, sockets, TV points, and so on. These markings guide the rest of the construction process, like plastering and decorating.
5. Wiring for Systems
Modern homes often include more than just power and lighting. The first fix can also include wiring for:
Internet and data points
Smoke detectors
Security systems
Heating controls (like smart thermostats)
Audio and speaker systems
All of these require careful planning to make sure the right cables go to the right place.
When Does First Fix Happen?
The first fix stage typically happens after the basic structure of a building is complete, but before any finishes are applied. That means:
After walls and floors are built
Before plastering, painting, or wallpapering
Before flooring is installed
Before kitchen units or bathrooms are fitted
It’s a narrow window of time where the building is ready for cables, but not yet closed off.
How Long Does First Fix Take?
The length of time depends on the size of the project. For a small house extension or a single room, it could take just a day or two. For a full house rewire or new build, it might take a week or more.
Electricians often work alongside other tradespeople, so timing and coordination are important. If delays happen during the first fix, it can affect the whole build schedule.
First Fix Tips for Homeowners
If you’re a homeowner going through a build or renovation, here are a few tips to make the most of the first fix stage:
1. Plan Ahead
Think about where you’ll want sockets, switches, and lights. Do you charge your phone next to your bed? Do you want USB sockets in the kitchen? It’s easier to get this right during first fix than to change it later.
2. Communicate with Your Electrician
Don’t be afraid to ask questions or request changes. Your electrician can offer advice and help you think through your needs.
3. Think About the Future
Even if you’re not installing a home network or smart lighting now, you might want to later. Ask your electrician to add the necessary wiring during the first fix. It’s much cheaper to do it now than to retrofit it later.
Common Mistakes to Avoid
Poor Planning: Changing your mind after plastering can be expensive.
Overloading: Trying to cram too many wires into one circuit can cause issues.
Ignoring Other Trades: Make sure electricians work in sync with builders and plumbers.
DIY Without Knowledge: Electrical work must follow safety regulations. Always hire a qualified electrician for the first fix.
Final Thoughts
First fixing electrics might not be the most visible part of a building project, but it’s one of the most essential. It sets the stage for a home that’s safe, functional, and built to your lifestyle.
Getting it right means thinking ahead, communicating well, and working with experienced professionals. From hidden wires to perfect socket placement, the first fix is all about laying the groundwork — so when the second fix comes around, everything just fits together beautifully.
Whether you’re building a dream home or updating an old one, understanding first fixing electrics helps you make smarter choices — and gives you a much smoother project overall.
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