Renovation and AREI: When Do You Need New Electrical Plans?
Not every renovation needs the same records. Learn how to distinguish substantial changes, existing parts, updated plans and inspection scope.
When does renovation lead to new plans and inspection?
The electrical scope matters, not the word “renovation”. Book 1 V06 requires substantial changes or extensions to be inspected before they enter service. That conformity inspection is generally limited to the added or modified parts. If the change affects an unchanged part, that part is included for the affected properties and mentioned in the report.
For substantial work on a domestic installation, the single-line diagram and position plan are prepared or updated. For a non-substantial change, a dated and signed short description may replace a new single-line diagram, but the position plan still shows the change. The AREI/RGIE does not provide a simplistic table that classifies every moved socket. Agree the scope with the electrician and, where necessary, the control body before work starts.
A practical decision path
- Is the work non-electrical? Painting and flooring do not alter the electrical installation.
- Is equipment merely maintained? Record an equivalent replacement and confirm that properties and protection remain unchanged.
- Are new conductors, circuits, sources or boards introduced? Treat this as a possible substantial change or extension until professionally classified.
- Do voltage, connection type, earthing or protection change? Effects may extend beyond the new component.
- Which existing sections are affected? Define them by circuit, board and actual cable path.
A new sub-board, dedicated EV or heat-pump circuit, board replacement or supply conversion therefore needs early professional review. A cover plate, lamp or equivalent switch replacement with no electrical-property change is closer to maintenance. These examples do not decide an individual case.
There is no blanket “contamination rule”
The popular term suggests that any intervention automatically subjects the whole house to current rules. Book 1 does not say that. Inspection of a substantial change is limited to changed or added parts. Only when a change affects properties of an unchanged part is that part inspected for those properties. Independent hazards can become visible during a visit, but that does not create an all-or-nothing rule.
Precise scope records matter more than the slogan. Identify circuits, cable sections, protective devices and rooms touched by the works. Mark the existing installation, new work and shared supply or protection points. This supports a professional scope decision but does not unilaterally limit the approved control body.
What Part 8 actually does
Part 8 contains specific derogations for existing parts, partly based on their installation period. It does not declare every old installation acceptable. Each derogation has a defined scope and often extra conditions. Equipment must remain safe; age never legitimises an immediate danger. New or substantially modified sections are designed to the currently applicable provisions.
For each existing section, record installation period, previous reports, cable and protection data, and later changes. A 1960s building can contain work from several decades. The construction year alone does not prove which derogation applies to one circuit.
Documentation for renovations
Survey without unsafe assumptions
Start with existing inspection reports, drawings, invoices and labels, then compare them with the real board. A qualified person can isolate circuits systematically and record which points actually lose supply. Live work and sealed equipment are not DIY survey methods. A suspected cable path is labelled as a hypothesis until verified.
Build a circuit inventory with identifier, rooms served, visible cable type and cross-section, protective device, RCD group, known junctions and fixed appliances. Keep unknown values separate from confirmed facts. Photographs preserve labels and condition but replace neither measurements nor a diagram.
Divide the renovation into work packages
Separate immediate safety defects, changes necessary for the construction scope, and optional comfort additions. This reveals what must be resolved before commissioning and what can wait. Review shared points first: main board, earthing, supply cable and common RCDs may connect several rooms. A new kitchen circuit is spatially local but electrically touches the board and its protection chain.
For every package, record initial state, intended change, affected existing properties and final state. Do not postpone the substantial/non-substantial classification until walls are closed. Inspection scope, measurement access and required tests influence sequence and timing.
Produce an as-built record
Do not copy intended positions into the final plan without checking. Compare sockets, switches, lights, boxes and fixed equipment room by room. Then match every circuit to its protection, conductor data and board position. When older parts installed before 1 October 1981 appear on the single-line diagram, identify them as older parts.
Give each diagram a number, revision and revision date. A short change note should name affected rooms or circuits. Retain previous released versions because they help explain when existing sections arose. Keep current documents available on site for supervision, inspection, maintenance, repair and later alteration.
Inspection and findings
Provide readable plans and supporting documents to the approved control body. A measurement or installation defect is not fixed by redrawing it: technical work must correct the cause. After remediation, align the installation and documents again. The inspection report, signed drawings, measurements and relevant product evidence then belong in the installation file.
PlanElec's bounded role
PlanElec connects floor plan, topology, board, single-line diagram and position plan, making shared references and PDFs easier to maintain. The detailed material list and working dossier remain pilot capabilities with declared coverage limits. They provide no price, manufacturer order, official report or conformity certificate. Qualified people remain responsible for design, work and assessment.
Three scope examples
A bathroom is rebuilt
New cables, sockets, lighting and protective measures form a new work package. Record which existing supply and board branch feed it. The electrician checks current bathroom zones, protection, conductors and bonding against the actual installation. Other rooms are not automatically “contaminated”, but shared or affected properties still require professional attention.
An existing circuit is repaired
For an equivalent replacement, record type and properties and verify safe restoration. If location, conductor, protection or function changes, reassess the scope. Calling work a repair cannot hide an actual extension.
The distribution board is replaced
A new board touches many shared protection and assignment records. Identify every outgoing circuit before removal. After installation, labels, RCD groups, phases, conductors and diagrams must agree with the actual population. Resolve unknown legacy circuits before reconnection instead of carrying forward generic labels.
Questions for the planning meeting
- Which parts are new, moved, replaced or unchanged?
- Which existing facts are documented and which require measurement or access?
- Which common supply or protection points are affected?
- Is the work a substantial change or extension, and who confirms that classification?
- Which drawings, descriptions, measurements and manufacturer documents are needed?
- When must inspection and document release occur in the construction sequence?
These questions create no legal guarantee. They prevent technical and documentary tasks surfacing only when the inspection is imminent.
In an occupied building, plan safe intermediate states as well. Unfinished circuits remain clearly isolated and labelled. Temporary supplies require professional execution and separate records. At each phase, identify which sections already match the as-built plan and which remain work in progress.
Houses with existing plans
If a current single-line diagram and situation plan exist:
- Update the plans — add new circuits, modified positions
- Mark clearly what is old and what is new
- Present updated plans to the inspector
Houses without plans (pre-1981)
Many older houses have no existing documentation. In that case (Art. 9.1.2):
- Survey the entire installation — including unmodified parts
- Create a complete new single-line diagram — for the entire installation
- Create a situation plan — draw all sockets, switches, lighting points
Warning: This is one of the most common reasons renovations become significantly more expensive than planned — the documentation requirement for the entire installation.
Plan effort without invented fixed prices
Cost depends on survey effort, missing records, circuit count, measurements, construction scope and control body. Old web ranges are not a quotation. Request separate estimates for survey, design, installation, inspection and possible corrective work. PlanElec is currently free in Early Access with no active payment flow, but that does not remove professional services.
The PlanElec advantage for renovations
With PlanElec, you can:
- Document the existing installation
- Add new circuits and review them with an advisory self-check of limited coverage
- Clearly separate old vs. new
- Export the result as PDF for the inspector
- Early Access currently free; payment processing is not active yet
Checklist for renovators
Before starting renovations:
- Check: Do my works trigger a re-inspection?
- Find existing electrical plans (if available)
- Budget for documentation + inspection
- Involve an electrician early (for the installation work)
- Use PlanElec for documentation (create plans yourself)
After renovation:
- Updated plans created?
- All new circuits in the single-line diagram?
- Inspection body contacted?
- Inspection report and any findings reviewed with the electrician?
Official source
- FPS Economy: RGIE/AREI Book 1, Version 06
- Especially relevant: section 3.1.2, subsection 6.4.7.3, Part 8 and dossier duties in Part 9.