Configured, costed,installed.
In window manufacturing every element is a one-off: profile, glazing build-up, fittings and dimensions produce a separate bill of materials for each line item – and whether the costing was right only becomes clear after installation. Between quotation, site measurement, variations and final invoice, margin is regularly lost. fabular brings configuration, project costing, installation planning and invoicing together in one flow.
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- Variant configurator
- Continuous costing
- Commissions automated
- 100 %
- Project transparency
- Real time
- Margin control
- 25+
- years of experience
- 1
- Costing from quotation to final invoice
Three problems in window manufacturing
Variants are costed by hand
Costing technical variants, dimensions and glass types by hand takes time and invites errors. The errors only surface during installation.
A configurator with automatic bill of materials and price derivation.
Costing runs in two tools
Quotation costing and post-costing sit apart from each other. A view of margins and project costs only emerges once the project is finished – too late.
Continuous costing from the quotation to the final invoice.
Commissions are calculated by hand
Field sales commissions are worked out manually. That invites errors and is hard for the people concerned to follow.
Automatic calculation, transparent for everyone involved.
This page is for window manufacturing and installation businesses with project work, who cost elements with many variants, produce to site measurements and install in construction phases – and who today only know their margin once the work has been signed off.
What is genuinely difficult in window manufacturing
Every element is a one-off, every building project a project of its own. The difficulty does not lie in production, but in the chain before and after it.
- No element is standard: profile system, glazing build-up, fittings, colour, glazing bar layout and dimensions produce a separate bill of materials for each line item.
- Not every combination is technically permissible. Glass weight, sash size and fitting class limit one another – and the error only surfaces during installation.
- Between quotation and production sits the site measurement. The real dimensions are only known once the shell is up, but the costing was done weeks earlier.
- A building project is delivered and installed in construction phases. The dates depend on trades that the window manufacturer does not control but has to plan around.
- Installation hours, additional services and variations arise on site and often only reach the system with the final invoice – if at all.
- Between the initial costing and the result sit material price changes, installation effort and complaints. The difference usually becomes visible after sign-off.
- A special report for one large customer, or a dedicated view of variations, does not have to be a development order: fabAI builds it through Vibecoding, in dialogue, straight on top of the audited costing logic.
Variant logic sits in people's heads
Whoever knows which fitting variant suits which sash dimension is usually one particular person in the business. When that person is on holiday, the costing comes out conservative or wrong – both cost money.
Costing and post-costing drift apart
Quotations are produced in one tool, the post-costing in another. The comparison is therefore manual work and only happens once the project is finished.
The site reports back too late
Paper measurement sheets, timesheets and sign-off records reach the office on Friday, sometimes later. Until then, variations are not invoiced and dates are not adjusted.
How fabular handles it
Configuration and quotation
- 1.Variants, dimensions and glass types driven by rules.
- 2.Bill of materials and price derived automatically.
- 3.Technical dependencies checked.
- 4.The quotation becomes an order without re-entry.
What does not fit together technically cannot be configured.
Project and costing
- 1.Costing and post-costing side by side.
- 2.Margins visible per line item and per project.
- 3.Dates coordinated across trades.
- 4.Site measurements captured digitally.
Installation and invoicing
- 1.Installation planning with resources and dates.
- 2.Mobile feedback from the site.
- 3.Digital sign-off records.
- 4.Commissions settled by rule.
From the first site measurement to the final invoice
A building project passes through the same five stations, whether it consists of twelve elements or two hundred. What matters is that every station builds on the same data.
- Step 01
Enquiry and configuration
Sales and field service
Elements are configured by rules: profile, glass, fittings, colour and dimensions. Impermissible combinations cannot be created in the first place, and the bill of materials and the price are derived from the configuration.
- Step 02
Quotation and order clarification
Internal sales
The quotation is created from the configuration and becomes an order without re-entry. Line items, construction phases and delivery dates are agreed with the site management or the architect's office.
- Step 03
Site measurement and release for production
before production starts
The site measurement is captured digitally and set against the quoted line item. Deviations lead to a priced change, not to a silent adjustment in the workshop.
- Step 04
Production and order picking per construction phase
Work preparation
Production follows the installation plan, not the order sequence. Elements are picked per construction phase and put together with accessories and installation material.
- Step 05
Installation, sign-off and invoicing
Site management and installation team
Installation dates are planned with resources, and hours and variations are reported back from the site by mobile device. The sign-off record and the scope actually delivered produce the interim and final invoices as well as the commission settlement.
What window manufacturers ask us
How are technical dependencies checked in the configurator?
Whether a combination is permissible is held as a rule, not as the knowledge of individual people. What does not fit together technically, for example a fitting variant beyond the permissible sash weight, cannot be configured. This means the check does not fall to the installation stage but to the quotation stage. Which rules your profile system and your suppliers impose is set up during implementation.
What happens if the site measurement differs from the quoted line item?
The site measurement is captured digitally and set against the costed line item. If it differs, that produces a priced change with a new bill of materials and a new price before production starts. The difference to common practice is that the adjustment is documented and can be invoiced, instead of being corrected silently in the workshop.
Can we invoice a building project in construction phases?
Yes. fabular supports interim and progress invoices as well as collective invoices. Elements can be assigned to construction phases, so that delivery, installation and invoicing follow the same split. The state of completion per phase stays visible, which considerably shortens discussions about quantities already delivered and already invoiced.
How do we see the margin before the project is finished?
Costing and post-costing sit in the same system and can be set against each other while the project runs. Material issues, installation hours and variations feed in as soon as they are posted. The contribution margin per line item and per project is therefore visible during the project, and not only once the final invoice is written and nothing can be steered any more.
How do installation hours and variations get from the site into the system?
The installation team reports hours, material consumption and additional services back by mobile device, and the sign-off record with them. The effort is therefore in the project the same day, and not only with the timesheet at the weekend. Variations that today regularly go uninvoiced are documented in this way and can be settled with the client on a factual basis.
How are field sales commissions calculated?
Commissions are determined by rules from the invoiced line items, based either on revenue or on contribution margin. Because the basis sits in the system, the settlement can be followed by the people concerned and is not the subject of recurring discussions. Which rules apply in your business, for example tiers or different rates per product group, is mapped during implementation.
Companies working with fab4minds
An extract from our customer base. These companies work with fabular; which industry solution they use varies.
- BayWa
- RWA
- Waldland
Before you change anything in your costing
A consulting engagement first clarifies where in your project work the margin is being lost. The result is a document you can work with internally – regardless of whether you continue with fab4minds afterwards.
Digitalisation consulting for window manufacturers
For businesses whose projects were costed with an adequate margin and still come out tight. We record the chain from configuration to final invoice and show where the difference arises.
- Record the variant logic and the costing basis and check whether they can be expressed as rules
- Examine the break between quotation, site measurement and release for production
- Go through the reporting of installation hours and variations for completeness
- Set costing and post-costing against each other on completed projects
Let us configure an element
Bring along a typical element with special requirements. We use it to show how the bill of materials and the price come out of it. For our consulting engagements the same applies: if the result does not help you, we refund the fee.