An electrician measuring cable inside an open old fuse board in a hallway

What affects consumer unit replacement costs in Bristol

7 min read
Costs
Consumer unit replacement quotes in Bristol vary because the job depends on the board, the circuits, the protection fitted and what the electrician finds behind the old enclosure. This guide explains the cost drivers in plain terms, so that a householder can see why one quote is higher than another and which questions to ask before agreeing to the work.

Replacing a consumer unit is one of the most common electrical jobs in Bristol, and it is also one of the most variable in price. The board itself is only part of the cost. The rest depends on how many circuits must be served, what protection the new unit includes, how the work is tested and certified, and what the electrician finds when the old enclosure is opened. This guide explains each of those factors so that a householder can read a quote with a clear picture of what is being bought.

Unit type and the number of ways

A consumer unit is sold according to the number of ways it can take, which is the number of devices it can hold. A unit with a small number of ways suits a simple flat with few circuits, while a larger house with a separate kitchen circuit, a cooker, an electric shower and several lighting circuits needs a bigger board. A quote that proposes a larger unit is not necessarily overpriced, because the extra ways allow the installation to grow and avoid a second visit later.

The type of enclosure also matters. Since 1 January 2016, BS 7671 has required a consumer unit in a home to have a non-combustible enclosure, in practice usually steel, or to be housed in a non-combustible cabinet, as the IET's note on the requirement explains. Within that rule, the make and finish of the enclosure affect both price and the appearance of the finished wall. Ask each firm to name the unit it proposes, so the difference between quotes can be checked against a specific product rather than a general description.

RCBOs compared with RCDs

Protection is one of the largest variables. A board can use a shared residual current device, which protects several circuits at once, or individual RCBOs, which protect each circuit on its own. An RCBO board costs more because it contains more devices, but it can make faults easier to isolate, because a tripped device identifies the affected circuit directly. The choice depends on the layout of the house and the advice of the installer.

Both designs must be selected to suit the installation. The IET's BS 7671 standard sets out the requirements for protection in new and altered installations, and a quote that follows it will explain how protection has been arranged. Ask the firm why it has chosen the protection it proposes and how the choice relates to the circuits in the house.

Testing and certification

Testing and certification add cost, but they are part of the job. Once the new board is installed, each circuit should be tested for continuity, insulation resistance, polarity and earth fault loop impedance, and the results should be recorded. The paperwork that follows is what proves the work was completed to the required standard. A quote that omits testing or certification is not comparable with one that includes them.

Replacing a consumer unit is notifiable work under regulation 12(6A) of the Building Regulations 2010, so the quote should show whether the firm will self-certify it through a competent person scheme or whether a building control fee must be added. Certification for notifiable work is normally provided by a registered firm. The NICEIC and NAPIT schemes both operate registers of firms that carry out electrical work and issue certificates, and a quote from a registered business should explain which certificate will be provided. Ask for a copy of the certificate template before work starts, so you know what you will receive.

Remedial work uncovered

The most unpredictable cost is the work that is only discovered once the old enclosure is open. Common examples include missing or inadequate earthing, damaged cables inside the board, overheated connections, a neutral that has been connected to the wrong terminal or an earth bonding that has been removed or never fitted. These items are often outside the scope of a simple board swap, but they must be dealt with before the installation can be signed off.

A sensible quote allows for this possibility. Some firms include a contingency. Others state that any remedial work will be quoted separately and agreed before it is carried out. The second approach is often fairer, because it lets the householder decide how to proceed. Ask the electrician to explain what they would look for before the job starts and how any findings would be reported.

Connections, earthing and bonding

Many replacement quotes include a check of the earthing and bonding of the installation. This means confirming that the main earthing conductor is connected correctly, that metal services such as water and gas pipes are bonded where required, and that the earth continuity is adequate. These checks take time, and they may reveal work that is needed elsewhere in the house, such as a bonding connection that was never completed.

Older houses in Bristol often need more attention here. Their installations were designed to standards that differ from current requirements, and they may have had partial upgrades over the years. An electrician who checks the earthing and bonding during the replacement is doing necessary work, even though it adds to the cost. A quote that treats these checks as optional should be questioned.

Access and location

The location of the old board affects the time needed. A board in an accessible hallway can be replaced more quickly than one in a cupboard under the stairs or a loft space. The enclosure may need to be moved if the existing position does not meet current requirements, and that can require new cables and plastering. Ask each firm whether it has assumed that the board will stay in place or be moved, and whether any making good is included.

Access to the property also matters. Some properties have limited parking, stairs that restrict the movement of materials or a fixed layout that makes it hard to protect the floors. These factors affect the time needed on site and should appear in the quote.

Labour time and access on the day

Much of the cost of a board replacement is labour, and labour depends on how long the job takes on site. The electrician must isolate the supply, remove the old board, check the cables that enter it, fit and wire the new enclosure, label every circuit and test the installation before reconnecting. A board with many circuits takes longer than a simple one. A board in a difficult location, such as a cupboard with little space or a loft hatch, adds time for safe access and for protecting the surrounding area.

Some firms quote a fixed price for the board, and others charge a day rate and estimate the time needed. Both can be sensible, but they distribute risk differently. A fixed price puts the risk of overrun on the firm, while a day rate leaves more of the risk with the householder. Ask each firm which model it uses and what would change the price, so that the comparison reflects the same assumptions.

Making sense of the total

When the quotes arrive, it helps to split each total into its main elements before comparing them. A typical breakdown includes the unit and its protective devices, the labour for removal and installation, the testing and certification, any remedial work allowed for, the making good and the cost of the materials that are not part of the unit. Once the totals are split this way, it is easier to see whether a difference lies in the equipment, the time or the risk allowance.

A lower total is not always cheaper in the long run. A firm that allows little time for testing or that excludes remedial work may appear competitive, but the difference will usually reappear as a variation or a second visit. A higher total is not always better value either, particularly if it includes items the house does not need. The useful question is whether each element is necessary for the property and whether the scope has been stated clearly.

Making a fair comparison

Lay the quotes side by side and check each one against the same list: the unit type and number of ways, the protection proposed, the testing and certification, the allowance for remedial work and any making good. Then ask each firm to explain the difference between its total and the others. The guide on BS 7671 wiring regulations explained for Bristol owners sets out the standard that the work should meet.

Readers who want a method for setting several board quotes side by side can use the comparing quotations guide. Any quote for a specific installation can be requested through the quote request page, and the services overview and frequently asked questions cover the wider scope of the work.

Sources and further reading

  1. BS 7671 - 18th Edition (The IET)
  2. NAPIT (NAPIT)
  3. NICEIC (UK Electrical Certification and Training)
  4. New non-combustible enclosure requirement for consumer units (IET)
  5. The Building Regulations 2010, regulation 12 (legislation.gov.uk)