> ## Documentation Index
> Fetch the complete documentation index at: https://docs.salvidia.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Event data checklist

> Every data item that feeds an event footprint, who holds it, and why the requests you make before the event matter more than the ones you make after.

Event data has one property that organisation data does not: most of it becomes unavailable once the event ends. A venue will pull a sub-meter reading for you during the build. Six weeks later, that period is gone and you are estimating from floor area.

So the order is different. Ask first, measure during, reconcile after.

For most events attendee travel is the largest single category by a wide margin, often outweighing everything else combined. Weight your effort accordingly.

## Venue and energy

| Data                          | Usually held by        | Arrives as                                              |
| ----------------------------- | ---------------------- | ------------------------------------------------------- |
| Electricity used by the event | Venue operations       | Sub-meter reading, or a pro-rated share of the building |
| Gas for heating or catering   | Venue                  | Bill or apportioned figure                              |
| Generator fuel                | Power contractor       | Delivery dockets or litres refuelled                    |
| Floor area and hours used     | Venue or your contract | Square metres and occupancy hours, for estimating       |

Ask for sub-metering when you book, not when you report. Most venues can isolate a hall if asked in advance and cannot reconstruct it afterwards.

## Travel and accommodation

| Data                       | Usually held by        | Arrives as                                   |
| -------------------------- | ---------------------- | -------------------------------------------- |
| Attendee origins           | Ticketing platform     | Postcodes or suburbs from registration       |
| Attendee mode split        | Attendee survey        | Percentage flying, driving, public transport |
| Exhibitor and crew travel  | Exhibitor forms        | Origin and mode per stand or team            |
| Staff and performer travel | Your own bookings      | Itineraries with route and class             |
| Hotel nights               | Bookings or room block | Nights by city and hotel type                |

Attendee travel is nearly always estimated rather than measured, and that is fine. Add one optional question to registration asking the attendee's postcode and how they expect to travel. Getting the mode split roughly right matters far more than precision on any individual journey.

## Suppliers, freight, and logistics

| Data                     | Usually held by    | Arrives as                                     |
| ------------------------ | ------------------ | ---------------------------------------------- |
| Freight to and from site | Logistics provider | Weight and distance per consignment            |
| Exhibitor freight        | Exhibitors         | Stand weight, or a per-stand assumption        |
| Production and AV        | Your suppliers     | Invoices, or activity data where they track it |
| Contractor travel        | Contractors        | Vehicle movements or spend                     |

## Catering and food

| Data                 | Usually held by         | Arrives as                                       |
| -------------------- | ----------------------- | ------------------------------------------------ |
| Meals served by type | Caterer                 | Covers by menu: beef, chicken, vegetarian, vegan |
| Drink volumes        | Caterer or bar operator | Units by category                                |
| Packaging            | Caterer                 | Disposable versus reusable, and quantities       |

Menu split is the number that moves this category. A caterer who can tell you covers by menu type gives you something far more useful than a total spend figure, and most can.

## Materials and waste

| Data                | Usually held by              | Arrives as                                         |
| ------------------- | ---------------------------- | -------------------------------------------------- |
| Waste by stream     | Waste contractor             | Tonnes or bin lifts: landfill, recycling, organics |
| Build materials     | Production or stand builders | Weights, or reuse assumptions                      |
| Signage and print   | Suppliers                    | Quantities and materials                           |
| Carpet and flooring | Venue or builder             | Area, and whether reused                           |

## Put it in the contract

The single highest-return action for event footprints is not a data request. It is a clause.

Venue and supplier agreements are where you secure data while you still have bargaining power. Ask for:

* A sub-meter reading for your halls covering your exact occupancy period
* Waste tonnages by stream, split for build, event days, and pack-down
* Catering covers by menu type
* Freight weights and origins from your logistics provider

Suppliers who provide this routinely will say yes without hesitation. Suppliers who cannot are telling you something useful about how the rest of the relationship will go.

## Where to go next

* [How to measure an event footprint](/guides/how-to-measure-an-event-footprint)
* [Requesting data from other people](/collecting-data/requesting-data)
* [What good data looks like](/collecting-data/what-good-data-looks-like)