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House rewires and consumer unit upgrades: signs, process and cost

8 min readLast reviewed June 2026

Rewiring is one of the more disruptive electrical jobs, so it is worth understanding when you actually need one versus a smaller upgrade. This guide explains the warning signs, what each job involves, and what drives the cost, so you can make an informed decision.

The short answer

A rewire replaces the old fixed wiring throughout a property; a consumer unit upgrade replaces just the fuse board with a modern unit that includes proper protection. You may need a rewire if the wiring is decades old or showing warning signs, while a consumer unit upgrade is a smaller job that brings your protection up to current standards.

What are the signs you need a rewire?

Some common indicators that wiring may be reaching the end of its safe life: - The property has not been rewired in several decades. - Old rubber, fabric, or lead-sheathed cabling is present. - An old fuse board with rewirable fuses rather than modern circuit breakers. - Frequent tripping, flickering lights, or warm or discoloured sockets and switches. - A burning smell near electrical fittings, which should be treated as urgent.

Not every old house needs a full rewire, and a good electrician will test before recommending one. An EICR is the proper way to establish the true condition rather than guessing.

What is the difference between a rewire and a consumer unit upgrade?

These two jobs often get confused: - A full or partial rewire replaces the actual wiring, cables, and accessories in the property. It is the bigger job and more disruptive. - A consumer unit upgrade replaces just the fuse board with a modern unit, typically adding RCD or RCBO protection that older boards lack.

Upgrading the consumer unit improves protection, but it does not fix tired wiring behind the walls. Sometimes a consumer unit upgrade is all that is needed; sometimes it is the first step that reveals wiring issues. Testing tells you which.

What does a consumer unit upgrade involve?

Replacing a consumer unit is usually a one-day job for a competent electrician. It involves isolating the supply, removing the old board, fitting the new unit with appropriate protective devices, testing every circuit, and certifying the work.

A modern consumer unit gives you better protection against electric shock and faults, clearer labelling, and the headroom to add circuits such as an EV charger or solar in future.

How does a house rewire work?

A rewire is staged so it is as manageable as possible: - First fix: new cabling is run, which involves lifting floors and chasing walls. - Second fix: sockets, switches, and the consumer unit are fitted and connected. - Testing and certification: every circuit is tested and the work is certified.

It is disruptive, and in an occupied home we plan it room by room to keep things liveable. We talk you through the sequence and timescale up front so there are no surprises.

What affects the cost of a rewire?

Rewiring is priced per property because every house is different. The main factors are: - The size of the property and the number of circuits, sockets, and rooms. - Whether it is a full or partial rewire. - Access: solid floors, plastered walls, and finishes affect labour. - Whether the property is occupied during the work. - Any additional work such as a new consumer unit or extra circuits.

We survey the property and give a written, itemised quote, so you can see exactly what is included rather than working from a rough national average.

FAQs

Common questions.

How long does a house rewire take?

It depends on the size of the property and whether it is occupied, but a rewire is a multi-day job rather than a one-day one. We give you a realistic timescale for your specific home as part of the quote, and plan around you where the property is occupied.

Do I need to move out during a rewire?

Not always. Many rewires are done with people still living in the property by working room by room, though it is dusty and disruptive. For larger or empty properties it can be faster to do it all at once. We plan the approach with you.

Will a rewire need replastering and redecorating?

A rewire involves chasing walls and lifting floors, so some making good is part of the job. We make good to a sound standard, but final decorating is usually handled separately. We are clear in the quote about what making good is included.

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