HOAI, VOB, GAEB, AVA, audit-proof record keeping: the key terms of planning and building, explained briefly, correctly and in relation to your task.
The German fee scale for architects and engineers, governing how fees for design services are calculated in Germany.
HOAI (Honorarordnung für Architekten und Ingenieure) is a German regulation that governs how fees for design services are calculated. It organizes services into service profiles and service phases 1 to 9 (LP 1–9) and sets the fee from the chargeable costs, the fee rate and a fee table. Current version: HOAI 2021.
The nine phases of a design commission under HOAI, from basic evaluation to project support.
Service phases divide a design commission under HOAI into nine steps: LP 1 basic evaluation, LP 2 preliminary design, LP 3 design, LP 4 approval planning, LP 5 execution planning, LP 6 preparation of contract award, LP 7 assisting the award process, LP 8 construction supervision, LP 9 project support. Each phase is assigned a percentage of the total fee.
A method for calculating the fee between the reference points of the HOAI fee table.
The HOAI fee tables state fees only for specific cost reference points. When the chargeable costs fall in between, the fee is interpolated linearly (§ 13 HOAI). Structify performs this interpolation automatically and traceably.
The German procurement and contract rules for construction works, covering the award and handling of construction contracts.
VOB (Vergabe- und Vertragsordnung für Bauleistungen) consists of three parts: VOB/A (award), VOB/B (contract execution, including change orders and acceptance) and VOB/C (general technical contract terms). In Germany it is the basis for many construction contracts, especially with public clients.
The German standardized data exchange format for tendering, award and billing in construction.
GAEB (Gemeinsamer Ausschuss Elektronik im Bauwesen) defines an XML exchange format for bills of quantities and bids. The file stages run from .X81 (bill of quantities) through .X83 (request for bids) to .X84 (bid). Structify imports and exports GAEB XML cleanly in the standard format.
Tendering, award and billing of construction works.
AVA stands for tendering, award and billing (Ausschreibung, Vergabe und Abrechnung): the three steps in which construction works are described, awarded to bidders and billed after completion. Its core is the bill of quantities (BoQ); bids are compared using the bid comparison.
A structured list of all construction works to be tendered, with quantities and descriptions.
A bill of quantities (BoQ) describes the construction works to be delivered as individual items, each with a quantity, a unit and an item description. It is the basis for the tender and the later comparison of bids. BoQs are usually exchanged as a GAEB file.
A tabular comparison of several bids item by item, to support the award decision.
A bid comparison sets the bids from several bidders side by side, item by item. It makes price differences, outliers and gaps visible and serves as the basis for a documented award recommendation.
A systematic on-site check of a construction project.
A site inspection is the planned walk of a construction site to record progress, defects and open points and to document them. The result is a site inspection report. Structify creates this report from voice, photo and note, even offline.
A running record of what happens on site each day.
A site diary (daily construction log) documents construction progress, weather, the personnel and equipment on site and any special events, on every working day. It serves as evidence, for example in change orders or disputes, and should be kept gap-free and auditable.
A deviation of the work from its contractually agreed condition, and the formal notice of it.
A defect exists when construction work deviates from the agreed or customary condition. With a notice of defects, the client reports the defect and sets a deadline for remedy. Structify captures defects with photo AI, pins them on the drawing and tracks deadlines into the warranty period.
An additional or changed service compared with the original construction contract.
A change order (Nachtrag under VOB/B) arises when services are added or changed during construction. For VOB contracts, the payment is determined under VOB/B Section 2. Change orders should be identified early, calculated traceably and drafted in a formally sound way.
The legal approval of construction work as substantially in line with the contract.
With acceptance, the client declares that the construction work has been delivered substantially in line with the contract. It is pivotal: among other things, it triggers the start of the warranty period, the due date of the final payment and the shift of the burden of proof.
Liability for defects after acceptance, within the limitation period.
Under warranty, the contractor is liable for defects that arise or appear after acceptance. The limitation periods differ by contract (BGB or VOB/B). Gap-free documentation supports claims in a dispute.
Tamper-proof, traceable and complete retention of documents.
Audit-proof record keeping (Revisionssicherheit) means that documents are stored so that they are complete, tamper-proof, traceable and retrievable. For tax-relevant records, the GoBD (the German principles for proper electronic bookkeeping and records) set out these requirements in detail. Structify Operate keeps the operations log audit-proof.
The German principles for proper management and retention of books and records in electronic form.
The GoBD are administrative rules of the German tax authorities for the proper management and retention of tax-relevant electronic records and documents. Among other things, they require traceability, tamper-proofing and completeness.
Continuous digital capture, structuring and filing of all records across the construction process.
Digital construction documentation is the capture, without re-keying, and structured filing of all records along the construction process, from site inspection through defects and the site diary to acceptance. The goal is auditable, retrievable documents instead of scattered notes and photos.
A transparency obligation of the EU AI Act: AI-generated content must be recognizable as such.
Article 50 of the EU AI Act requires AI-generated or AI-edited content to be labeled transparently and users to be informed about the use of AI. In force since 2 August 2026. Structify labels AI suggestions and keeps them traceable and correctable.
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