Decorative Lighting Specification Guide: Dimensions, Finishes, Voltage, and Installation Requirements

The decorative lighting specification sheet provides the size, material, surface finish, electrical parameters and installation instructions of the product. In the case of standard products, it assists buyers to determine rapidly if the fixture is appropriate for a project. It acts as the technical foundation to quote, make samples, and approve custom products.

This article will cover the main specification parameters in a decorative lighting specification sheet and how to understand overall dimensions, mounting dimensions, voltage, light source, dimming method, load capacity and IP rating. It also points out the information which must be verified with the manufacturer prior to ordering.

1. What Does a Decorative Lighting Specification Sheet Include?

It’s more than an introduction to a product: it’s a complete decorative lighting specification sheet. It is an essential technical document that will be utilized during design, procurement, production, transportation, installation and final acceptance. Most manufacturer’s specification sheets have the following four kinds of information; although they may be arranged in different orders.

Decorative Lighting Specifications

1) Product Dimensions

The fixture geometry and installation space are defined by the dimension specification, this comprises the overall dimensions, mounting dimensions, adjustable dimensions and product weight.
Typical information includes: Overall Height, Width / Diameter, Projection (wall light projection), Canopy Size, Suspension Length (rod or cable length), and Net Weight.

2) Material and Finish Specifications

Material specifications describe the strength, weight, durability, and decorativeness of the fixture.
The following is usually specified on a specification sheet: Base metal material (Brass, Stainless Steel, Aluminum, including alloy grade), Shade material (Glass, Fabric, Acrylic), Decorative materials (Crystal, Marble, Wood), Surface finish (Electroplated Brass, Brushed Brass, Powder Coating, PVD, coating thickness, color tolerance, UV resistance rating, etc.).
The specification sheet may also contain technical information on metal wall thickness, glass thickness, marble type, crystal grade and colour codes (RAL or Pantone) for high end custom projects.

3) Electrical Specifications

Electrical requirements ensure that the fixture will meet the electrical power supply requirements and performance of the fixture for the light. Another part of them is among the most crucial one at the time of International procurement. Common specifications are: Input Voltage, Frequency, Wattage, Lamp Base, Light Source (integrated LED or replaceable lamp), Color Temperature, CRI (Color Rendering Index), Luminous Flux, and Dimming Compatibility.

4) Installation Specifications

The installation specifications will be used to assess whether the fixture can be correctly installed onsite. Typically include installation instructions (suspended, ceiling mounted, wall mounted or floor standing), canopy dimensions, mounting hole locations, range of suspension rod/cable adjustments, product weight, load-bearing specifications, installation environment (Indoor / Outdoor), fall protection specification and ventilation clearance.

2. Understanding Decorative Lighting Dimensions

The size of a fixture is only one factor in determining its size. They are also directly involved with transportation, installation, and visual impact in the space. If the fixture is for an engineering project, it is not sufficient to confirm just the diameter or height of fixture. Also, you need to check the installation clearance, adjustment range and site conditions are met.

Lighting Fixture Dimensions

1) Overall Dimensions

The most basic parameters of a specification sheet are overall dimensions. Most contain Overall Height, Width, Diameter, Length and Net Weight.
These dimensions are not only important to make sure that the fixture is proportionate to the space but also they play a part in packaging, transporting, and lifting plans. For instance if the chandelier in the lobby is 1800 mm in diameter, it can be fully produced, but if it is too big to fit in the shipping package and it is too large to fit in the container/elevator, it may never get to the installation site.
For custom fixtures, verify the proportions against the actual space during the design stage. A common practice is to create a full-scale CAD layout or a 3D model to confirm the relationship between the fixture, ceiling, furniture, and building structure before production begins.

2) Mounting Dimensions

One of the most common specifications that can get the construction site reworked during procurement is the mounting dimensions. These generally cover Canopy Size, Mounting Hole Pattern, Location of junction box, Overall Size of the top driver box, Maintenance Access, Minimum installation clearance, and Installation depth.
Some projects do state the dimensions of the fixture, but fail to mention the size of the canopy. For example, a 100 mm junction box is used for a building, but an 80 mm fixture canopy is used, they are unable to cover the entire box. As an alternative, too big a canopy could provide an obstruction for sprinkler heads, HVAC diffusers or ceiling details. Size(s) of mounting should be checked as per real project by architectural and electrical and MEP drawings.

3) Adjustable Dimensions

Adjustable dimensions are required for pendant installation and are given the desired installation tolerance. These parameters are often adjustable, such as the range of the suspension cable, combinations of suspension rod lengths, setting angle of the fixture, head rotation angle of the wall-light, and the height adjustment range of the floor-lamp.
It is for instance possible to have an 8 m ceiling height in the lobby and a mock-up room height of 4 m. Where modular suspension rods or adjustable steel cables are used, the same product can also be used for a variety of applications and drastically cut the redesign and new tooling expense.
When designing a custom project, the specification sheet should include Minimum Hanging Height and Maximum Hanging Height to prevent problems at site due to suspension cables that are too short or too long.

3. Common Material and Finish Specifications for Decorative Lighting

Materials and finishes not only affect the look of a decorative fixture, but also its weight, strength, corrosion resistance, maintenance and service life. The words “brass” or “glass” alone do not suffice in procurement of projects. Material type, method of fabrication and finishing should also be specified.

1) Metal Material Specifications

The most important material for making decorative lighting is metal. The strengths, weights, corrosion resistance, and fabrication capabilities of various metals are widely different.

A specification sheet will usually describe the metal type (Brass, Stainless Steel, Aluminum, Iron), material grade (304 stainless steel, 316 stainless steel, etc.), whether it is a tube, sheet or solid, wall or sheet thickness, and its manufacturing process (casting, tube bending or CNC). The following table shows some of the more common metals used.

In the case of large chandeliers, the material specification is directly related to the total load bearing requirement. Solid brass provides a heavier look and feel, but is much heavier than aluminum alloy. The hollow tube will also lighten the overall weight of the chandelier and is more appropriate for extra large chandeliers or hanging at high levels.

Material Specification Sample

2) Glass, Stone, and Crystal Specifications

The materials used to decorate fixtures are important elements of the fixture’s appearance and make up an important part of the luxury decorative lighting. Generally, a specification sheet will include the glass type you are looking for such as blown glass, pressed glass, bent glass, crystal type such as K9 crystal, optical crystal, etc., stone type such as natural marble, engineered stone, thickness of the glass, and color and/or texture specifications.

Glass Specifications

Typical requirements include: low-iron extra-clear glass can generally achieve visible light transmittance of approximately 91% or higher; bent glass should be fully annealed to prevent later cracking caused by residual stress; decorative blown glass should maintain a wall-thickness tolerance of ≤0.5 mm to keep the lighting effect consistent across the batch. Stone components should receive a sealing treatment to reduce staining, oil penetration, and long-term darkening. K9 high-transparency crystal can achieve light transmittance of 92% or higher.

For natural marble, some variation in veining and color should be accepted as a natural characteristic. However, the sample should be approved in advance to avoid disputes caused by pattern variation after mass production.

K9 Crystal Specifications

3) Surface Finish Specifications

The surface finish specification dictates the surface color, the fixture’s gloss and its durability. They also impact on colour stability, UV resistance and salt-spray resistance.
Typical specifications comprise the type of finish (Electroplated, Powder coated, Painted, PVD), the finish (Polished, Brushed, Matte, Antique), colour coding (RAL, Pantone, colour reference), and Gloss Level. Here are some common requirements:

For engineering projects, suppliers are usually required to provide a Finish Sample for approval. The approved sample should then serve as the color reference for mass production and final inspection, reducing the risk of color variation between batches.

4. Which Electrical Parameters Should Be Confirmed for Decorative Lighting?

Electrical specifications determine whether the fixture meets local power supply standards, lighting requirements, and control-system requirements. They are also one of the areas most likely to cause problems in international procurement because standards vary by market.

1) Voltage and Frequency

Each country and region has its own power supply standards, so it is necessary to be consistent with the target market requirements in terms of voltage and frequency.
Common power supply specifications include 120V/60Hz for North America, 220–240V/50Hz for Europe, and SELV solutions such as DC12V or DC24V, which are commonly used in decorative lighting. The specification sheet should distinguish between the fixture input voltage and the LED module operating voltage. For example, it should state “AC220V input, DC24V LED module” rather than simply “24V.”

Electrical Specifications

Apart from this, special areas like swimming pools and bathrooms must be protected from electric shock in accordance with the installation zone. Overall luminaire safety may be IEC 60598-1 and the relevant product specific luminaire standards. Low voltage alone should not be used as the basis for determining safety.

The driver, power supply or control system may not be compatible with the local mains supply, and the fixture may flicker, have a reduced service life or fail to operate the driver. In this, case export projects typically employ a power supply configuration that matches the final country of installation.

2) Light Source Type

Normally the specification sheet will indicate what type of light source the fixture is fitted with and if it can be changed during future lightings.
They are integrated LED, LED Bulb, E26/E27 lamp holders and replaceable lamp bases (GU10 and G9).
Therefore, integrated LED can be widely used in modern decorative fixtures, and the appearance and design flexibility are better than traditional LED. Standard lamp holders make products easier to maintain since a lamp can be replaced without replacing the whole fixture.

3) Wattage, Luminous Flux, and Color Temperature

These are three parameters that are used together to determine how the lighting performs, and are some of the most critical optical parameters in the specification sheet.
Wattage (W), Luminous Flux (Lumens), Color Temperature (Kelvin), and Color Rendering Index (CRI) are typically specified on the specification sheet.
Brightness is not directly proportional to wattage. With increasing efficiency of LEDs, wattage does not necessarily translate to the same lumens, but can vary considerably from one light source to another. In the case of engineering projects, it is more important to consider the luminous flux, therefore.
Color temperature sets the mood to the place. Common options include:

• 2700K: warm yellow light, suitable for high-end residences and hotel guestrooms.
• 3000K: warm white light, commonly used in hotel lobbies, restaurants, and commercial spaces.
• 4000K: neutral white light, suitable for offices and public areas.
• Above 5000K: cool white light, mainly used for display or functional lighting.

For high-end decorative lighting, a CRI of 90 or above is generally recommended so that wood, stone, fabrics, and artwork render with more natural and accurate colors.

4) Dimming System Compatibility

In large commercial and stage-lighting applications manufacturers typically state the type of dimming that is supported, usually including options like Triac Dimming, 0-10V Dimming, DALI, Casambi, Zigbee or DMX.
Not all control systems will work with a dimmable fixture. A DALI driver, for instance, cannot be directly plugged into a Triac dimming device and different manufacturers can also have compatibility problems with each other.
In engineering projects using a fixture, make sure that the protocol of the fixture driver, the power supply and the control system are all identical. This will eliminate the possibility of being installed with the fixtures but not properly dimming them, or, having the control system operating abnormally.

5. How Do Installation Specifications Affect a Project?

Installation specifications are crucial not only to ensure proper installation, but also to the cost of construction, future maintenance needs and operational safety.

1) Installation Method

There are various methods of lighting decoration, which can be discerned from the type of lights. As a rule, the appropriate mounting type is designated on the specification sheet, e.g. Pendant Mounted, Ceiling Mounted, Wall Mounted, Recessed Mounted or Floor Standing.

The different installation methods have varying site requirements. Thus, in the event that there is a large chandelier, for example, another load-bearing system in the form of an embedded steel structure or a support needs to be installed in place of the conventional gypsum board ceiling. Also, the position of the junction box and the height at which it is mounted need to be checked with the wall lights.

Lighting Installation Drawing

2) Fixture Weight and Load-Bearing Requirements

The Net Weight, Gross Weight, recommended load bearing and fixing requirements are generally detailed in the Specification sheet.
The specification sheet for large-sized chandeliers is not supposed to list the weight only. The number of suspension points, load at each suspension point, center of gravity, and canopy structure shall all be stated in the specification sheet. The lighting fixture shall not be hung directly over gypsum board or suspended ceilings. The use of an embedded steel structure, anchors, and suspension points will depend on the site conditions and load at each suspension point.

3) IP Rating and Installation Environment

The IP Rating shows the level of protection against the penetration of dust and water into the fixture and is a key consideration when evaluating the appropriate installation location.
Common ratings include:

• IP20: for dry rooms in an interior, for instance bedrooms, living room, hotel guestrooms.
• IP44: Bathroom, Corridor, Semi-Open Area.
• IP65: for outdoor, outside courtyard, landscape lighting, and places where rain will fall for long periods of time.
• IP68: Designed for use in swimming pools, water features and underwater luminaires. Besides the IP rating, the specification should also include the maximum installation depth, the method used to seal the cable from the outside and the location of the driver.

This is just the IP rating that is related to dust and water resistance of the enclosure. It is not an indication of higher corrosion resistance of the fixture. For instance, the use of the proper metal material or surface finish is a requirement for a fixture even if it is dry rated to IP65 even in a coastal application, it can still corrode, fade, or suffer coating failure.

4) Maintenance and Replacement Access

Once a decorative fixture is installed, it needs to be cleaned, light sources may need to be replaced, or drivers require maintenance. Future access and maintenance conditions should therefore be also covered in the specification sheet.
Key points to verify will include if the driver can be easily removed and replaced without the need to disassemble the unit, if the LED module can be serviced later, if the shades or glass or crystal can be removed easily, and if there is enough access to maintain the unit or if an access opening has been provided.
In the case of large hotel chandeliers, for instance, they may be constructed in such a way that the modules or numbered installation sets can be removed. A local glass element, crystal component or light source is damaged and maintenance staff can only replace the damaged element, not the whole fixture. This can substantially lower the long-term maintenance expenses and downtime.

6. Which Specifications Should Be Confirmed Before Purchasing or Customizing Decorative Lighting?

Specifications must be carefully reviewed before ordering, and in a systematic order.

Drawing Review Before Ordering

1) Does the Product Specification Meet the Project Requirements?

First, confirm that the fixture meets the actual requirements of the project. The following items should be checked carefully:

• If the product size is appropriate to the space;
• Whether the fixture weight is less than the load bearing capacity of the building;
• If the materials, colours and surface finishes meet the design purpose;
• Whether the lighting is able to satisfy the lighting requirements of the space;
• If an installation does not correspond to the provisions on site.

If custom projects – use approved technical drawings as a final basis for production. This reduces rework due to changing of specification later.

2) Do the Electrical Specifications Meet Local Standards?

Electrical specifications must meet the requirements of the target market. Confirm the following:

• Whether the input voltage and frequency match the local mains supply;
• Whether the light source and driver comply with local standards;
• Whether the method of dimming is suitable for the project control system;
• Whether the plug, power cord, and wiring method comply with local regulations.

3) Are Custom Dimensions, Colors, or Installation Methods Required?

Common customization requirements include:

• Adjusting the fixture dimensions or number of tiers;
• Changing the suspension rod or cable length;
• Changing the metal color or surface finish;
• Changing the glass, crystal, or stone material;
• Adjusting the installation method and fixing structure;
• Customizing the voltage, dimming system, or light-source parameters.

Any customization needs should be agreed upon in the quoting phase. As design changes occur on a regular basis during the production process, it can impact the delivery timeline and project budget.

4) Checklist for Confirming Specifications with the Manufacturer

Before placing the formal order, confirm each item in the following checklist:

For certification and compliance requirements in different markets, refer to our “Decorative Lighting Certification Guide: UL, ETL, CE, RoHS, and Compliance Requirements” for applicable markets and key procurement considerations.

7. How to Read a Decorative Lighting Specification Sheet

Don’t only look at appearance, wattage, and voltage when looking at a specification sheet. For each parameter, determine if it is well-defined and if measurable acceptance criteria are given. The following three typical examples illustrate common issues.

1) Type One: Ambiguous Parameter Definitions

Case 1 – Original specification: LED power 30W, color temperature 3000K, high color rendering.
Problem Analysis
“30W” does not specify whether it refers to the LED module power or the total luminaire input power. If 30W refers to the LED output side, the total input power will be higher after driver losses are included, which will also affect thermal design and electrical load calculations. Recommended specification: total luminaire system power 30W ±5%;
“3000K” does not define an allowable color temperature tolerance. Fixtures installed in the same space may therefore show noticeable warm/cool variation and create an uneven visual effect;
“High color rendering” provides no numerical requirement. It should specify CRI Ra ≥90 and R9 >50 for restaurants, hotel guestrooms, and spaces where accurate skin tone, wood, and fabric rendering is important.
Improved specification: Total luminaire input power 30W ±5%, color temperature 3000K ±50K, CRI Ra ≥92, R9 ≥50.

Ambiguous Parameter Definitions

2) Type Two: Finish Description Without Acceptance Criteria

Case 2 – Specification: Surface finish: black metal coating.
Problem Analysis
The specification does not specify polyester powder coating or fluorocarbon coating and it does not define coating thickness or salt-spray requirements. A supplier can provide a typical thin layer of paint which will fade in 6 months of outdoor use.
Enhanced specification: Outdoor-use super durable black polyester powder coat, coating thickness 80-120 μm, batch colour difference ΔE<2, no exposed metal, no pinhole, no peeling and no noticeable runs.

3) Type Three: Incomplete Electrical and Dimming Parameters

Case 3 – Specification: 220V, dimmable LED.
Problem Analysis
The specification does not specify what the luminaire class, isolation requirements for the driver or dimming protocol is. It would then be quite a challenge in matching the fixture to the intelligent control system, and it would also be quite easy to create flickering.
Improved specification: Class II LED luminaire using a compliant isolated driver, input AC220V, 50Hz; supports 0–10V dimming with a dimming range of 5%–100%, with no visible flicker; driver complies with IEEE 1789 flicker requirements.

8. Conclusion

The specification sheet of a decorative lighting should contain all the details regarding the dimensions, materials, surface finishes, electrical design, and installation conditions, and it needs to be coherent with the finalized drawings. In cases of custom work, the more detailed the specification sheet is, the easier the whole process will be to control.

Postmodern Lighting can offer you help regarding specification sheet review, material and surface finish recommendation, electrical design, technical drawing, and custom quotation according to your drawings and target market conditions.