Design guide: retrofit and refurbishment of existing installations
Method, regulatory requirements and design checks for retrofit and refurbishment of existing installations, from data collection to commissioning.
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Overview
Most projects do not start from scratch: they work on existing installations, with poles, lines and constraints already in place. This Centro Studi Lumeitalia guide sets out the working stages of a retrofit and refurbishment of existing installations project: gathering baseline data, defining performance requirements, calculation, component selection and on-site verification. The aim is not a recipe valid everywhere, but an orderly path that removes implicit decisions and makes the design verifiable by whoever must approve, build and commission it.
Applicable standards
The regulatory reference for retrofit and refurbishment of existing installations is not a single document but a coordinated set of standards covering performance, safety and environmental impact. In design practice the following documents drive the main choices.
EN 13201 / EN 12464 — performance requirements to be met.
IEC 60364 — verification of the existing electrical installation.
Italian CAM for lighting — constraints in public projects.
Baseline data to collect
Design quality depends on the quality of initial data. Before opening the calculation software you need the real geometry of the area, expected operating conditions, client constraints and applicable local rules. Recording these systematically prevents undeclared assumptions from surfacing at commissioning, when correcting them costs far more.
In this specific case, data collection must document the existing situation with measurements and photographs, record information on the existing electrical installation and clarify who will handle maintenance: the planned cleaning and replacement cycle feeds directly into the maintenance factor used in the calculation.
From requirement to calculation
Once requirements are set, the lighting calculation must prove the proposed solution meets them under the worst expected conditions, not ideal ones. The model must reproduce the real geometry, plausible surface reflectances and a maintenance factor consistent with the management plan. A calculation run with optimistic parameters yields an installation that is compliant on paper and inadequate after a few years of service.
Good practice is to attach both results and assumptions: the maintenance factor adopted and its justification, reflectances, real heights and spacings, and the photometric files used. This documentation makes the design reproducible and lets the commissioning engineer reconstruct the reasoning.
On-site verification and commissioning
Commissioning compares field measurements with design values, accounting for tolerances and measurement conditions. The protocol should be agreed in advance: measurement grid, instruments, ambient conditions, supply status and luminaire operating hours at the time of verification. Without a shared protocol, the discussion on results shifts from numbers to interpretations.
Recurring critical points
The difficulties that most often emerge in retrofit and refurbishment of existing installations projects are not about product selection, but about defining requirements and verifying results.
Assessing the real condition of poles, lines and boards before replacing luminaires.
Avoiding energy savings that mask a failure to meet standards.
Scheduling works to reduce disruption for residents and users.
Design approach
An orderly method drastically reduces variations during works and disputes at commissioning. Three choices make the difference from the earliest stages.
Detailed asset survey with a record per light point and structural checks on supports.
A lighting design proving compliance with the required classes.
Functional lots by homogeneous area with progressive commissioning.
Parameters to verify
Asset survey — good practice — record per light point
Compliance check — EN 13201 / 12464 — classes and requirements achieved
CAM requirements — Italian CAM — mandatory in public works
Most frequent mistakes
Non-conformities found at commissioning almost always come from three causes: requirements not declared or declared without a reference standard, calculation run on idealised geometry, and an optimistic maintenance factor. All three can be avoided at zero cost during design.
Existing conditions surveyed with measurements, photos and electrical schematic
Performance requirements declared with the reference standard
Maintenance factor justified and consistent with the management plan
Calculation run on real geometry, not an idealised one
Applicable local and environmental constraints verified
Commissioning protocol agreed before works start
As-built documentation handed over to the operator
Key takeaways
A retrofit and refurbishment of existing installations project holds up over time when requirements are declared, the calculation reproduces real conditions and on-site verification follows an agreed protocol. Component selection matters, but comes later: without measurable requirements even the best product delivers a result that cannot be demonstrated. Centro Studi Lumeitalia makes its technical office available to review requirements and design checks.
Methodological note: This content is written for technical information purposes by Centro Studi Lumeitalia and does not replace the lighting design or a full reading of the standards cited. Applicable performance values are those of the standards in force at design time.
Domande frequenti
Is a retrofit enough to be compliant?+
No: replacing the luminaire improves efficiency, but compliance depends on the overall lighting result, verified by calculation.
When should poles be replaced too?+
When structural checks reveal corrosion, or when the existing geometry cannot achieve the required class.
Where should a retrofit and refurbishment of existing installations project start?+
From a written definition of performance requirements and verification conditions: this step drives every later choice and makes the result either disputable or defensible at commissioning.
Which documents should be requested from the supplier?+
Photometric files of the proposed luminaires, declaration of conformity, lifetime data declared per IES LM-80 with its conditions, the maintenance schedule and warranty terms.
Lumeitalia — Sistemi LED professionali
Lumeitalia è il brand di illuminazione LED professionale di Mya Tech S.r.l., azienda italiana fondata nel 2011 a Trezzano sul Naviglio (MI); il brand è attivo dal 2020.