Key points
- Gap in the BoQ: bills of quantities usually describe the main product; required accessories often follow only from the system and its installation instructions.
- Three types: mandatory accessories, recommended add-ons and cross-selling each need different handling in the quote.
- Two sources of knowledge: AI can derive what belongs together from fixed rules and from completed quotes.
- Your team decides: whether an add-on belongs in the quote depends on the project; the AI makes the suggestion, your team approves it.
As of 3 November 2026
Transparency note: this guide is published by Scalera. Information about Scalera comes from our website; information on ETICS kits comes from EOTA's European Assessment Document EAD 040083-01-0404. Corrections are welcome at info@scalera.ai.
Why are accessories and add-ons so often missing from quotes?
Because the bill of quantities rarely lists them in full and the knowledge about them is spread across people. An item describes the main product; which profiles, fixings or seals a system also needs is often known only to those who have quoted it many times.
Under time pressure, the team focuses on assigning an article to every item. Add-ons then drop out, even when they matter for the system to work or for the customer.
At dormakaba there was also a structural factor. The case study cites unused cross-selling opportunities across product portfolios, knowledge asymmetry across partners and the erosion of expert know-how due to demographic shifts (Scalera, dormakaba case study).
What counts as an accessory and what as an add-on?
For the quote, a simple distinction helps: does the system work without the item? The answer determines how binding the suggestion is and how it appears in the quote.
| Type | Typical example | Handling in the quote |
|---|---|---|
| Mandatory accessory | Fixing, connection or closing part without which the system cannot be installed properly | Include it, or clearly mark it as by others or not included |
| Recommended add-on | Part that improves installation, durability or maintenance | As a note or separate item, never silently priced in |
| Cross-selling | Product from another portfolio that fits the project | Separate from the tender quote, for example as an additional offer |
Scalera's own classification. Which parts are mandatory in each case is defined by the documentation of the respective system.
The distinction also matters because a BoQ has its own item types. How provisional or alternative items affect the quote total is explained in Analysing a bill of quantities with AI.
What does a facade example show?
It shows that a system covers more than its main components. The European Assessment Document for External Thermal Insulation Composite Systems (ETICS) lists four kit components: adhesive, factory-made thermal insulation product, mechanical fixing devices and rendering system, with adhesive and fixings depending on the fixing method (EOTA, EAD 040083-01-0404).
In addition, an ETICS may include ancillary components defined in the manufacturer's installation instructions. The EAD names mastics, corner strips, joint covers, corner profiles and base profiles, among others, and states that these parts are not part of the assessed kit (EOTA, EAD 040083-01-0404).
For quoting, this means that an item such as «supply ETICS» is often not fully answered by the kit alone. Which profiles and connection parts belong to it follows from the system documentation and the project. According to the EAD, the manufacturer may also produce individual components itself or purchase them.
A quote is only complete when the system works on site, not as soon as every tender item has a price.
How does AI suggest accessories and add-ons?
It recognises which products regularly appear together in your quotes and suggests them the next time a similar case comes up. According to Scalera, the AI learns from employee behaviour, remembers when multiple products were offered together and can suggest product combinations (Scalera, FAQ).
Product matching comes first: only once the main product has been reliably assigned can suitable add-ons be derived (Scalera, Product Matching). Which product data should be in place for this is described in Product data for tenders.
Where does knowledge about related products come from?
From two complementary sources. Fixed rules capture what belongs together technically, for example from parts lists or system descriptions. At Frauenthal, integrating business rules such as margins and cross-selling was part of the data architecture, one of the project's three key success factors (Scalera, Frauenthal case study).
Learned knowledge comes from completed quotes. With each completed offer, Scalera remembers which products were offered for each tender position (Scalera, FAQ). This way, the experience of long-serving staff flows into suggestions that new colleagues can use as well.
Where does your team still need to decide?
Wherever the project departs from the usual case. A suggestion is based on frequent combinations; whether it fits a specific case depends on requirements found only in the BoQ, the drawings or the conversation with the customer.
- Work by others: when the BoQ explicitly excludes parts or another trade supplies them.
- Project requirements: when the preliminaries prescribe specific brands, colours or classes.
- Uncertain matches: Scalera uses confidence scores and flags low-confidence matches for review (Scalera, FAQ).
- Customer relationship: when a customer always sources certain accessories themselves.
The AI's role, then, is to make sure nothing relevant is forgotten. The decision on what goes into the quote stays with the people who know the project and the customer.
How does the quote stay comparable despite add-ons?
By keeping add-ons visibly separate from the tender items. A client compares quotes item by item; pricing extra items unnoticed into unit rates makes that comparison harder and invites queries.
- Answer tender items unchanged: quantity, unit and item number stay as tendered.
- Disclose mandatory accessories: name included parts in the item text or mark missing parts as not included.
- List recommendations separately: as a note or additional item with a short rationale.
- Offer cross-selling separately: for example in a separate additional offer, so the main quote stays comparable.
What impact can be seen in practice?
At dormakaba, the solution includes a cross-selling engine that systematically identifies additional revenue opportunities. According to the case study, cross-selling increases average deal size by a typical 10 to 25 percent, and offer quality is consistent across distributed partners (Scalera, dormakaba case study).
The link to speed matters: partners process 2–3× more tenders with the same resources (Scalera, dormakaba case study). A more complete quote therefore need not be slower, as long as the suggestions appear in the same step as the product matches.
How do you get started with accessory suggestions?
- Choose a system: a product system with many recurring quotes and a clear parts list.
- Capture mandatory accessories: from installation instructions and system descriptions, list the parts without which the system does not work.
- Store rules: technical relationships and business rules, for example which add-ons are suggested by default.
- Let it learn from quotes: use completed quotes as a learning base and confirm or reject suggestions in daily work.
- Measure: how often accessories had to be added afterwards and how the value per quote develops.
What such a test with your own tenders looks like is shown in Piloting AI tender software. If confirmed quotes should then flow into your ERP, see ERP integration for tenders.
Frequently asked questions about accessories and add-ons in quotes
Which software automatically suggests missing accessories in quotes?
AI assistants for quote preparation can do this: they read bills of quantities, match products and learn from completed quotes. At Scalera, the AI learns from employee behaviour and can suggest complementary products and accessories (Scalera, FAQ). How to compare such tools is covered in Piloting AI tender software.
What is a system offer?
A quote that covers a working overall solution rather than individual items: the main product, the required components and suitable accessories. Typical cases include facades, drainage, doors and access solutions, or building services.
What is the difference between an add-on and an alternative product?
An add-on is offered in addition to the product, an alternative replaces it. Alternatives come with their own rules on equivalence, covered in Winning with alternates.
Does the AI also learn from other companies' quotes?
Not at Scalera. The offers you complete are used only for your own product suggestions; there is no cross-customer AI training (Scalera, FAQ). Suggestions are therefore based on the combinations your own team has offered.
Does the AI recognise accessories when the tender names a third-party product?
Scalera recognises both your own products and competitor products in specifications and suggests the best matching alternatives from your catalogue (Scalera, FAQ). Once the main product is replaced by one of your own items, the accessories should fit that item, not the brand originally named.
Can I start with a single product area?
Yes. According to Scalera, many customers start with their highest-volume or most standardised product lines and expand later (Scalera, FAQ). For accessory suggestions, a system with a clear parts list and many recurring quotes works well.
Does an AI suggestion replace a product configurator?
Not necessarily. A configurator encodes fixed technical rules; an AI also learns from quoting behaviour and reads requirements from tenders. When each tool fits is compared in CPQ vs AI quote calculation.
Key takeaways
- A quote that covers every tender item is not automatically a complete system offer.
- Mandatory accessories, recommended add-ons and cross-selling need different handling in the quote.
- AI derives suggestions from fixed rules and from your team's completed quotes.
- Keep add-ons visibly separate from the tender items so the quote stays comparable.
- 150+ companies already trust Scalera (Scalera, Product Matching). In a demo you can see how Scalera suggests accessories and add-ons for your range.