Monday morning in inside sales: a construction company sends a file with the extension .X83 and asks for prices on 240 line items by Thursday. A GAEB file is the German standard format for exchanging bills of quantities (BoQ) between planners/specifiers, owners, bidders and suppliers. The file extension tells you which phase of the tender process the file is in and what you are expected to do with it.

Key takeaways

• GAEB stands for Gemeinsamer Ausschuss Elektronik im Bauwesen (the Joint Committee for Electronics in Construction). Its exchange format GAEB DA XML is currently valid in version 3.3 (as of 2023-01).

• The file extension shows version and phase: D = version 90, P = version 2000, X = DA XML. The digits 81 to 89 and 93 to 97 stand for the exchange phase.

• Most important for suppliers: X83 (request for quotation) comes in, X84 (quote submission) goes back with prices.

• You can open the files with AVA or estimating software or with a viewer. To price them, you need a fill-in function.

• The bottleneck is rarely the file. It is matching each line item to your own item master.

What is a GAEB file and what is the GAEB format?

The GAEB format is a structured, software-independent file format for the electronic exchange of construction information, above all of bills of quantities with line items, quantities, short texts and long texts. It is defined by the Gemeinsamer Ausschuss Elektronik im Bauwesen and is recognized as the national standard for tendering, awarding and billing.

According to the GAEB FAQ, the rules are developed by the working group "Programmsysteme" (software systems), which includes public building authorities, architects and engineers, the construction industry, universities, DIN and software vendors. Implementation in software is the responsibility of the software vendors themselves. Whether a program implements the interface correctly can be checked through a certification by the Bundesverband Bausoftware (BVBS, the German construction software association).

Which GAEB versions exist: 90, 2000 and DA XML?

There are three generations: GAEB 90 (extension D), GAEB 2000 (extension P) and DA XML (extension X). New tenders today usually arrive as an XML file, but older files with .D83 or .P83 still show up, for example from existing projects.

Sources: GAEB data exchange, GAEB downloads, GAEB FAQ.

Two points matter in practice. First, according to the committee, version 90 and DA XML are not compatible. Converters only transfer content that exists in both formats. Second, for version 3.3 the committee does not state compatibility with the syntax of 3.2 and older. If a file cannot be read, a version conflict is therefore the first suspect.

What do X81, X83, X84, X86 and the other GAEB phases mean?

The two digits after the letter name the data exchange phase, that is, the purpose of the file in the process. The bill of quantities moves from the description (X81) through the request for quotation (GAEB X83) and the quote (X84) to the award of the order (X86). Phases 81 to 86 have the same name in all GAEB versions.

The full list for GAEB DA XML 3.3 according to gaeb.de:

The "Sender → recipient" column reflects the usual flow. The GAEB FAQ explicitly describes it for X81, X83 and X84. Many explainer pages only list X81 to X86 or assign the wrong content to the digits. For distributors and manufacturers, the trade phases X93 to X97 are particularly relevant, because they cover price requests and orders between bidder and supplier.

What does a GAEB file look like?

A GAEB DA XML file is a text file with project details, a structure of item numbers (OZ) and the individual line items with quantity, unit, short text and long text. In the X84, unit prices and total amounts are added.

Example (simplified, anonymized): One line item from an X83 in civil engineering.

In greatly simplified form, this line item sits in the following XML elements of the file:

In the X84, the bidder adds the unit price for each line item. The structure, the item numbers and the texts stay unchanged. Otherwise the client cannot automatically import the quote into its price comparison.

How do you open a GAEB file?

You open a GAEB file with AVA or estimating software that has a GAEB interface, or with a viewer. Free viewers are available online. To enter prices and create an X84, you need a viewer with a fill-in function, according to the GAEB FAQ.

This is how an X83 is typically processed at a distributor or manufacturer:

1. Import the file and check the version (D83, P83 or X83; for XML, the version number).

2. Review lots and sections, and hide trades that are not relevant.

3. Match each line item to your own item master, often via the long text rather than the short text.

4. Request missing items from upstream suppliers.

5. Calculate prices, surcharges and freight, and write them into the line items.

6. Export as X84 and, if needed, add an alternative bid as X85.

Many viewers and converters offer an export to Excel. That helps with reading, but getting the prices back into a valid X84 remains the critical step. Converters and viewers are third-party products, and the committee does not test them itself. For software vendors, it provides a GAEB XML checker on its download page.

What problems often occur with GAEB files?

The most common problems are the wrong phase, version conflicts and line items that cannot be matched unambiguously to an item. The file itself is usually correct. The difficulty lies in the content and the further processing.

• Wrong phase: You receive an X81 or X82 instead of an X83. Then the request for quotation is missing as a frame, and some programs cannot create an X84 from it.

• Version conflict: Your software only reads GAEB 90 or only XML 3.2.

• Brand-neutral long texts: The long text describes properties ("ring stiffness SN 10"), not your item number. Matching to the item master remains manual work.

• Special item types: Provisional items and alternative items are handled differently from standard items.

• Equivalent products: You want to offer an alternative product. This is what the alternative bid (X85) is for.

When is a GAEB viewer enough, and when is it not?

A free viewer is enough if you receive few, small BoQs per month and matching to your range is quick. For planners and construction companies that create BoQs themselves and calculate labor, AVA or estimating software is the right tool.

The limits show with large BoQs and many parallel requests. Then it is not opening the file that costs time, but searching for matching items for hundreds of long texts. An AI solution also does not replace AVA software for planners: it helps with pricing incoming BoQs, not with creating tenders.

How does Mercura process GAEB files?

Mercura, an AI software for quote and order automation in technical sales, reads bills of quantities as GAEB file, PDF, Excel, scan or photo. Each line item is matched to the supplier’s own catalog, including the long texts, and checked against the specification. These are the GAEB phases Mercura reads and writes:

The sales team reviews every quote before it is sent. The average match rate is 92% and depends on customer and catalog. At building technology manufacturer REHAU, Mercura delivers product suggestions for up to 98% of BoQ line items (REHAU success story). More on the process: Quotes and tenders.

Bring a real bill of quantities: in 30 minutes we show you how Mercura handles it in your process. Book a call

Conclusion

The GAEB format is not rocket science: the extension shows version and phase, and for suppliers X83 in and X84 out are what count. If you know the current version 3.3 and the trade phases X93 to X97, you will also understand unusual files. The real work is in matching line items to your own range. That is where it is decided whether a BoQ is priced in hours or in days. How Mercura prices a BoQ from start to finish is shown on the Quotes and tenders page, and the article Bill of quantities describes how a BoQ is built.

Further reading

• Quotes and tenders: turn every request into a quote

• Bill of Quantities (BoQ): Structure, Item Types and Processing

• Quoting Software Compared for Distributors and Manufacturers

• Customer story: REHAU (building technology manufacturer)

• GAEB Software or AI: Which Tool for Which Job?

• Mercura vs. kinisto: BoQs, Orders and Supplier Requests

Frequently asked questions

Can Mercura export a quote as GAEB X84? Yes. Mercura reads tenders as X83, D83, P83 or X81, exports the approved quote as GAEB X84 and creates supplier price requests as GAEB P93 or Excel.

What is a GAEB file? A GAEB file is a bill of quantities or another construction award data set in the standardized GAEB format. It contains structure, line items, quantities, short and long texts and, depending on the phase, prices.

What do I use to open an X83 file? You open an X83 file with AVA or estimating software with a GAEB interface, or with a viewer. To enter prices, you need a viewer with a fill-in function.

What is the difference between X83 and X84? X83 is the request for quotation without prices that the client sends to bidders. X84 is the quote submission: the same file with the bidder's prices, sent back to the client.

Which GAEB file do I need to submit a quote? To submit a quote, you usually need an X84 (D84 or P84 for older procedures). You submit an alternative bid additionally as X85.

What is a D83 file? A D83 file is a request for quotation in the old GAEB 90 format. It is line-oriented and, according to the committee, not compatible with DA XML. Converters only transfer shared content.

Can I convert a GAEB file to Excel? Yes, many viewers and converters export the data to Excel. For submitting a quote, however, the prices have to go back into a valid X84, otherwise the client cannot import them.

What does X86 mean? X86 is the order award: with it, the client sends the awarded bill of quantities to the contractor. The contractor's confirmation follows as X87.