How to Compare Quotes for DALI Lighting Control: A Line-by-Line Evaluation Method

Why DALI bids are hard to compare

Two bids for the same DALI lighting control scope can differ by a wide margin and neither will be wrong — because each bidder resolved a different set of open questions in their own favour. The open questions are almost always the same six: how many addresses are being commissioned, what the controller licence actually covers, whether network gateways and their configuration sit inside the price, whether the interface to other building systems is included, how long warranty and support run, and what will trigger extra charges later. Comparing totals hides every one of these. Comparing structures exposes them.

Figures and rates in the worked example below are explicitly illustrative; they exist to demonstrate the comparison method, not to quote anyone's prices.

Step 1: Write the scope schedule before anyone quotes

Publish a scope schedule with your invitation to tender. At minimum it should state:

• number of individually addressable control gear and control devices, broken down by zone;
• the zone and scene count;
• required control functions: occupancy, daylight, time scheduling, manual override, emergency testing;
• systems the controller must interoperate with, and which protocol each uses;
• the required commissioning deliverable: address list, scene schedule, as-built drawing, operator training, post-occupancy adjustment window;
• warranty and support terms;
• the format bidders must submit in.

Where the client has not decided something, say so and require bidders to price it as an option. A quote that prices an unresolved question as included is a variant, not a compliant bid.

Step 2: Demand a bid form with the same line items

Use the seven-line structure from the estimating method, so that every bid can be dropped into the same table:

1. DALI-2 control gear;
2. input devices;
3. bus power supplies, cable and containment;
4. application controllers, gateways, licence — split hardware from recurring licence;
5. commissioning and programming;
6. integration and interface works;
7. training, documentation, warranty and post-handover support.

Then require a plain-language qualification list. Any bidder who will not open their structure is telling you something useful.

Step 3: Normalise the quantities

Before comparing money, compare counts. Put the bid lineup against your own schedule and check:

• Does their address count match yours? A lower count often means ganged luminaires or a group-based design, which changes the control functions available.
• Does their subnet count respect the bus limits — 64 control gear plus 64 control devices per subnet and around 250 mA of bus current, with the cable-length limits of IEC 62386-101 applied to the actual routes? A single subnet proposed for an area that clearly needs two will show up as a low hardware line and a high commissioning line later.
• Are input devices individually addressed certified products, or are they feeding a proprietary sensor bus?

Step 4: Compare the controller line on its ownership terms

The same controller can appear in a bid at half the price of another with a completely different cost curve over ten years. Ask each bidder to state, in the quote:

• licence model: perpetual, subscription, per-site, per-device;
• what the licence includes and what is an add-on module;
• device count ceiling and the cost of exceeding it;
• who hosts the management platform and who holds the data;
• what happens to control functions if the licence lapses.

A perpetual licence plus support contract and a subscription are not the same product merely because year-one numbers are close. Convert both to a five-year and a ten-year total and compare those.

Step 5: Interrogate the commissioning line

Commissioning is where bids diverge most, and it is also where the sharpest questions are available:

• Are hours quoted, or is commissioning a lump sum? Ask for the assumed hours and productivity basis.
• Is post-occupancy adjustment included, and for how long — typically a defined window after handover during which settings are tuned?
• Are out-of-hours and access restrictions priced?
• Is emergency-lighting test configuration and the first annual test included?
• What is the day rate for changes requested after the commissioning period closes?

A low commissioning line combined with a high variations rate is a known commercial pattern. Price the risk, not just the number.

Step 6: Check the compatibility and certification evidence

DALI-2 and D4i products are certified against the IEC 62386 parts through the DALI Alliance, whose certified product database is public (accessed 11 November 2026). Ask for the specific product entries for drivers, input devices and controllers, not just a marketing statement. Then check the interface claim: a controller that reads luminaire data (Part 251), energy and power (Part 252) or diagnostics (Part 253) only delivers value if the specified drivers support those same parts. A mixed set from different certification generations is a legitimate, low-cost choice — but it must be a deliberate one.

Step 7: Score, don't just rank

Convert every bid to the same commercial basis, then score against weighted criteria that reflect the risk the client is actually carrying. An illustrative weighting for a small commercial fit-out:

Do not let a weighted score override a hard disqualifier: a bid that omits the licence or excludes commissioning entirely should be returned for clarification rather than averaged into silence.

Worked example: three bids normalised (illustrative figures)

Scope: 120 addressable luminaires, 40 input devices, two subnets, 25 scenes, one interface to a building management system. All figures invented for arithmetic.

On subtotals Bid B looks cheapest. Normalise it: add the licence at the client's own estimate for a comparable platform ($1,980 over five years, illustrating the difference between models), add an integration allowance ($1,400) and add commissioning for the balance of addresses Bid B omitted (25 unexplained addresses at the same productivity as Bid A, about $1,300). Bid B moves to roughly $16,500. Bid C, meanwhile, has embedded a multi-year licence in year one, so its ten-year position improves relative to the others.

The conclusion is not that Bid B was dishonest. It is that three bidders answered three different questions because the invitation allowed them to.

Red flags worth an explicit clarification request

• Address count lower than the layout implies, with no explanation of ganging.
• Controller described without a licence term.
• Commissioning as a lump sum with no hours and no post-occupancy window.
• Certification claimed for the system rather than for the named products.
• Warranty stated for hardware but silent on software updates and support.
• Emergency-lighting testing mentioned in the narrative but absent from the priced lines.
• Withdrawal or validity periods too short to complete a fair evaluation.

Lifecycle tip: keep the comparison alive

The bid comparison table is also the template for the ten-year cost review. Keep the columns, replace quoted prices with actual invoices, and add maintenance, replacement drivers, licence renewals and the costs of any variation. Two years in, that table tells you whether the cheapest bid was cheap.

Sources and date

• DALI Alliance certified product database and certification overview: https://www.dali-alliance.org/dali2/ (accessed 11 November 2026).
• DALI Alliance data specifications, Parts 251–253 (luminaire data, energy reporting, diagnostics), accessed 11 November 2026.
• IEC 62386-101 bus installation limits as summarised in industry technical material: up to about 64 control gear plus 64 control devices per subnet, roughly 250 mA bus current, cable limits around 300 m at 1.5 mm² (accessed 11 November 2026).

Standard, certification and database details are as published by the named bodies. All prices, weights and productivity assumptions in this article are illustrative model inputs used to demonstrate comparison mechanics and are not supplier quotations.