FAQ — everything about tenders, GAEB & Bidlane
Answers about the platform, security, GAEB formats, workflow, calculation and international tenders. All on one page — searchable and always up to date.
About Bidlane
What is Bidlane?+
Bidlane is a free online editor for tender and bill-of-quantities files. You can upload GAEB files (X81–X86), BoQs, Excel, PDF, CSV and XML straight in the browser, edit them, and export to your preferred format.
Is Bidlane really free forever?+
Yes. The core features — upload, editing and export of GAEB and BoQ files — are and stay free. No trial, no hidden paywall, no subscription.
How is Bidlane funded?+
Through restrained, high-quality advertising from partners in construction, software and wholesale. Instead of selling licenses, our advertisers keep the tool free for everyone.
Do I need to register?+
No. Bidlane works without sign-up, without email, without an account.
Do I need to install software?+
No. Bidlane runs entirely in the browser. No installation, no plugin.
Which devices does Bidlane support?+
Any modern device with a current browser — Windows, macOS, Linux, ChromeOS, iPad and Android tablets.
Which browsers are supported?+
Recent versions of Chrome, Edge, Firefox, Safari and Brave.
Does Bidlane work offline?+
It needs internet on first load. After that, editing happens locally in your browser session.
Which languages are available?+
Currently German, English, French and Spanish. The language is detected from your browser.
Can I use Bidlane internationally?+
Yes. Bidlane is reachable worldwide and supports international tender and BoQ formats.
Who is behind Bidlane?+
Bidlane is built and operated by Ziller Beteiligungs-UG (haftungsbeschränkt), managed by Marc Ziller. We come from the trades ourselves.
How can I give feedback?+
Reach us via the contact form or email. We keep improving Bidlane step by step along real-world practice.
Security & Privacy
Where are my files processed?+
File processing happens in your browser session. Content is not permanently stored on our servers.
Are my tender files stored?+
No, not permanently. They live in your current browser session and are discarded when you close the tab.
Is Bidlane GDPR-compliant?+
Yes. We process as little personal data as possible. Details are in our privacy policy.
Can anyone else see my file?+
No. Uploaded files are only visible inside your session.
Do you set cookies?+
Only technically necessary storage, e.g. to remember your language preference.
Do you track my usage?+
No personalised tracking — only anonymised technical statistics.
What data is shared with advertisers?+
Ads are served contextually. The content of your files is never shared with advertisers.
How secure is the transfer?+
All communication is encrypted via HTTPS/TLS.
Can I delete my data?+
Yes — just close the browser tab. Local data is also removed on manual reset.
Is Bidlane suitable for confidential tenders?+
Since processing happens locally in your browser, Bidlane is suitable for sensitive content.
Are backups of my files created?+
No. You are responsible for storing exported files securely.
How do you handle security vulnerabilities?+
Known security issues are addressed promptly. Reports reach us via the contact in the imprint.
GAEB basics
What is GAEB?+
GAEB is the German standard for the electronic exchange of tenders, offers and billings in construction.
What does the .x83 extension mean?+
.x83 is a GAEB XML file for the offer-request phase — typically the BoQ a bidder fills with prices.
What is an X81 file?+
An X81 file contains an empty BoQ without quantities.
What is an X82 file?+
An X82 file is a cost estimate — quantities are present, prices are not.
What is an X83 file?+
X83 is the offer request with quantities — the bidder fills in unit prices and returns it as X84.
What is an X84 file?+
X84 is the bidder's offer with unit prices and totals.
What is an X85 file?+
X85 contains alternative bids or additional bidder information.
What is an X86 file?+
X86 is a change-order request — usually during construction.
What is an X89 file?+
X89 transmits award notices or alternative-bid responses.
What is the difference between X83 and X84?+
X83 is the request without prices, X84 is the response with bidder prices.
What is GAEB DA XML?+
GAEB DA XML is the current exchange format (3.x), replacing the older D81/P81 formats.
What are D81 and P81 files?+
Older GAEB formats based on fixed-length records.
Which GAEB version should I use today?+
If possible, GAEB DA XML 3.2 or newer — the current industry standard.
How do I open a GAEB file?+
With Bidlane directly in the browser — upload or drag & drop.
What is an OZ (item number)?+
The unique position number in the BoQ, e.g. 01.10.0020.
What is a title in a BoQ?+
A grouping element bundling positions of one trade or section.
What is an optional position?+
A position only billed if the work actually occurs — not part of the offer total.
What are alternative positions?+
Optional services the client calls off as needed.
What is hourly-rate work in a BoQ?+
Items billed by hours worked, typically for non-quantifiable services.
Formats & conversion
Which formats can Bidlane read?+
GAEB X81–X86, D81, P81, XLSX, XLS, CSV, XML, TXT and PDF tenders.
Which formats can I export?+
GAEB X83/X84/X86, Excel (XLSX), CSV and PDF.
Can I convert GAEB to Excel?+
Yes. Upload the GAEB, edit it and export as XLSX.
Can I convert Excel to GAEB?+
Yes, if the spreadsheet has the typical BoQ columns. Bidlane detects the structure.
Can I edit PDF tenders?+
Yes. Bidlane extracts items from PDF BoQs for further processing.
How accurate is PDF detection?+
Bidlane analyses layout and columns. Complex layouts may need manual review.
How do I convert D81 to X83?+
Upload the D81 — Bidlane reads it and lets you export as X83.
Can I merge GAEB files?+
Yes. Open multiple BoQs and combine them into one project.
Are long texts preserved?+
Yes, including formatting like paragraphs and bullets.
Are images in BoQs supported?+
Embedded images in GAEB XML are recognised and re-embedded on export.
Can I import CSV with custom columns?+
Yes. Map the columns during import.
Which character encodings are supported?+
UTF-8 is recommended. ISO-8859-1 and Windows-1252 are also recognised.
Workflow & editing
How do I upload a file?+
Drop it on the upload area on the home page or click to choose.
How do I edit unit prices?+
Click the unit-price field and enter the new value. Totals update automatically.
Can I change quantities?+
Yes, directly in the table cell.
How do I add new positions?+
Use the New position button at the end of a group.
Can I delete positions?+
Yes, individual positions can be removed.
How do I save my work?+
Bidlane keeps the state in your session. For permanent storage, export the file.
How do I export the finished file?+
Click Export and choose the format. The download starts in the browser.
Can I have multiple projects open in parallel?+
Yes — use multiple browser tabs.
Can I add notes to positions?+
Yes, internal notes can be captured.
How do I calculate surcharges?+
Apply surcharge factors to single positions or the whole BoQ.
How does BoQ search work?+
Type keywords, item numbers or units — the table filters in real time.
Tender tips
How do I price a BoQ correctly?+
Start with quantities, set unit prices based on current market data, then add surcharges for material, labour, equipment, risk and profit.
What are the most common offer mistakes?+
Forgotten positions, wrong quantities, unrealistic unit prices and missing bidder declarations.
How do I handle optional positions?+
They are listed but not part of the total. Still calculate them realistically.
What does general contractor vs. construction manager mean?+
GC = does the work itself, CM = subcontracts everything.
What is the VOB?+
The German standard for awarding and executing construction contracts. Part A: award, B: contract, C: technical.
VOB vs BGB construction contract?+
VOB follows the standardised VOB/B rules; BGB follows general work-contract law.
How do I submit on time?+
Watch format, deadline, required documents and use the requested platform.
What are alternative bids?+
Bidder-proposed alternatives — only allowed if explicitly permitted.
What is a self-declaration of suitability?+
Proof that the bidder meets requirements for expertise, capacity and reliability.
What is an unusually low bid review?+
The client checks economic viability of suspiciously cheap bids.
How do I price materials correctly?+
Use current wholesale prices, account for waste, storage, transport and price-escalation clauses.
How do I calculate equipment costs?+
Via the equipment list — holding and repair costs plus fuel and operation.
What are general overheads?+
Indirect costs like admin, accounting, insurance — typically 7–15% of production cost.
Difference between cost and price?+
Cost = your internal expenditure. Price = sales value including risk and profit.
How does the quantity-deviation rule work?+
Unit prices can be renegotiated for deviations greater than 10% (VOB/B § 2.3).
What are change orders?+
Modified or additional work — priced based on the original calculation basis.
What is the submission?+
The public reading of bids, today usually electronic.
What does award mean?+
The official acceptance of the offer — the contract is formed.
International tenders
What is a BoQ (Bill of Quantities)?+
A structured list of items with quantities, units and unit prices for a construction tender.
What is a DPGF in France?+
Décomposition du Prix Global et Forfaitaire — French equivalent of a BoQ.
What are Mediciones in Spain?+
The Spanish quantity take-off as part of a Presupuesto.
Which standards apply internationally?+
BIM/IFC, NRM (UK), CSI MasterFormat (USA), DPGF (FR), ÖNORM (AT), SIA 451 (CH).
Does Bidlane work with English BoQs?+
Yes. Excel, CSV and PDF BoQs in English are supported.
Can I use GAEB internationally?+
GAEB is a German standard but is also used in Austria, Switzerland and Luxembourg.
What is ÖNORM A 2063?+
The Austrian standard for BoQ data exchange.
What is SIA 451 in Switzerland?+
The Swiss norm for electronic data exchange in construction.
Question not answered?
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