How Parks and Recreation Departments Should Compare Sports-Lighting Proposals

Direct answer

Sports-lighting proposals cannot be compared on price until they are normalised to the same calculation grid, the same maintained illuminance target, the same light-loss factor, and the same pole and fixture count. Two proposals quoting different assumptions produce different totals for reasons unrelated to product quality. Normalise the assumptions first, then compare price, warranty terms, and the documentation each vendor will actually deliver.

Who this is for

Parks and recreation directors, facility managers, purchasing agents, and municipal engineers reviewing two or more sports-lighting proposals for a court, field, or multi-surface complex. It is written for the person who has to defend a recommendation to a council or board, not only to choose a supplier.

Why price comparison fails without normalisation

A sports-lighting proposal is a bundle of assumptions with a number at the end. Change any assumption and the number changes.

Consider two proposals for the same field. Proposal A calculates to 30 maintained footcandles on a 30-foot grid with a light-loss factor of 0.90. Proposal B calculates to 30 maintained footcandles on a 15-foot grid with a light-loss factor of 0.80. Proposal B will almost always require more fixtures, more wattage, or taller poles — and will therefore cost more. That does not make Proposal B worse value. It may mean Proposal B is being honest about depreciation over the maintenance interval and Proposal A is not.

The same applies to pole count. A layout using four poles instead of six may cost less in structure and trenching while producing worse uniformity. Uniformity is not visible in a price column.

Inputs required before proposals can be compared

Before you can rank proposals, you need the following defined once, by the owner, and issued to every bidder in identical terms:

1.Sport, level of play, and governing standard. Recreational, high school, collegiate, or tournament play carry different illuminance and uniformity targets. Confirm which standard and which edition the governing authority has adopted.

2.Calculation grid spacing and extent. State the spacing and whether the grid covers the playing surface only or includes runouts and surrounds.

3.Maintained illuminance target. State it as maintained, not initial.

4.Light-loss factor and its components. LLF is not a single number; it combines lumen depreciation, luminaire dirt depreciation, and other factors. Require each bidder to state the components and the maintenance interval assumed.

5.Mounting height and pole locations. Either fix them, or require each bidder to state theirs and justify any change.

6.Spill and glare evaluation points. Name the boundary points and the observer locations. Without named points, spill claims cannot be compared.

7.Existing infrastructure to be reused. Poles, foundations, conduit, and service capacity. Reuse assumptions drive cost more than fixture price does.

8.Documentation deliverables. State which records must accompany the proposal and which must accompany the shipment.

If these are not defined in the solicitation, the proposals will not be comparable and no amount of spreadsheet work afterwards will make them so.

What gets evaluated, and how each figure is labelled

The distinction that matters most to a purchasing decision: everything in a proposal is calculated, reported, listed, or specified. Nothing in a proposal is field-measured, because nothing has been installed yet.

A comparison sequence that survives an audit

Step one — completeness. Reject nothing yet. Score each proposal on whether it contains every deliverable the solicitation named. Missing items become clarification requests, not silent assumptions.

Step two — assumption normalisation. Build one table with a row per assumption and a column per bidder. Grid spacing, LLF, mounting height, pole count, fixture count, connected load, maintained target. Any bidder whose row differs from the solicitation must explain the deviation in writing.

Step three — re-calculation where needed. If a bidder used different assumptions, ask for a re-run on the solicitation's assumptions rather than adjusting their numbers yourself. Adjusting photometric results by hand is not defensible.

Step four — technical evaluation. Compare uniformity, spill at named points, glare treatment, structural verification status, and documentation completeness. Record findings in writing with the source of each figure.

Step five — commercial evaluation. Compare price, warranty terms and what they cover, freight and installation scope, lead time, and service response commitments.

Step six — total cost view. Include connected load and energy cost, lamp or module replacement expectations, access equipment required for service, and control system licensing or subscription costs if any.

Step seven — recommendation. Write the recommendation so a reader who was not in the room can follow it from the solicitation to the award.

Questions that separate proposals quickly

Ask each bidder, in writing:

•Which specific photometric report supports the fixture data in your calculation, and may we have it?

•What light-loss factor did you use, what are its components, and what maintenance interval does it assume?

•At which points did you calculate spill, and who chose those points?

•Has a licensed structural engineer verified the poles and foundations for the proposed fixture EPA and weight at this site, and will that verification accompany the submittal?

•Which documents will ship with the product, and which are available now?

•What is covered by the warranty, what is excluded, and where is the controlling document published?

•If a field measurement after installation differs from the calculation, what is your position?

The last question is diagnostic. A vendor who promises that field results will match the calculation is either misunderstanding the physics or overstating. Calculated and field-measured results are different categories of information; Article 6 in this series covers why.

Retrofit versus new construction

For new construction, the bidder controls pole locations and mounting heights, so proposals will differ structurally and the normalisation step matters most.

For a retrofit onto existing poles, the poles are a fixed constraint and the differences move to fixture selection, mounting hardware, aiming, and — critically — whether the existing structure has been verified for the new fixture EPA and weight. A retrofit proposal without structural verification is incomplete regardless of price. See the existing-pole retrofit checklist in this series.

What can change the answer

•The governing standard or its adopted edition changes the illuminance and uniformity targets.

•A change in maintenance interval changes the defensible light-loss factor and therefore the fixture count.

•Discovery that existing poles cannot carry the new load changes the project from a retrofit to a partial rebuild.

•Local ordinances on spill, curfew, or pole height may constrain layouts that are otherwise acceptable.

•Federal or state funding may attach domestic-content requirements that eliminate otherwise compliant products. See the Buy American Act and BABA article in this series.

•Utility rebate programmes may require DLC-qualified products, which narrows the eligible field before price is considered.

Verification checklist

1.Confirm the solicitation defined sport, level of play, and governing standard including edition.

2.Confirm the solicitation defined calculation grid spacing and extent.

3.Confirm the maintained illuminance target was stated as maintained.

4.Confirm every bidder stated their light-loss factor and its components.

5.Confirm every bidder stated mounting heights and pole locations.

6.Confirm spill evaluation points were named by the owner, not by each bidder separately.

7.Confirm each fixture's photometric report has been supplied and matches the model quoted.

8.Confirm certification and qualification records are verifiable by file number or model in the issuing directory.

9.Confirm structural verification for poles and foundations is included or scheduled, by a licensed engineer.

10.Confirm the warranty document is published and reviewable, not summarised in a proposal paragraph.

11.Confirm the documentation deliverables list is answered item by item.

12.Record the assumption-normalisation table in the procurement file.

Duvon's role and limits

Duvon Lighting supplies sports and area lighting products and supporting product documentation. We can provide photometric data files, product records, and effective projected area and weight figures for structural review. We can prepare calculated layouts for our own products.

We do not certify photometric results, we do not perform structural engineering, and we do not issue field measurements in place of an independent measurement. Where a project requires a licensed engineer's stamp, that work belongs to the engineer of record. Where a project requires a comparative evaluation of competing proposals, the owner or the owner's engineer performs it.

Next step

If you are preparing a solicitation or evaluating proposals now, send us the sport, surface dimensions, level of play, and any existing pole information. We will return the product documentation an evaluator needs, and a calculated layout for our products on the assumptions you specify.