Without a dedicated bills of materials service, producing BOMs eats up time as a project grows and the number of components increases, and that is exactly where drawing offices often get stuck. A drafter recounts components by hand, a list falls out of sync with the latest version of the drawing, and the project lead only discovers the error at handover.
We take this work off your hands and set up the bill of materials so that it moves with the model instead of sitting separately alongside it.
If a component changes in size or quantity, the list updates automatically, without anyone having to edit a cell by hand. That not only saves time, it also prevents the errors that arise when a drawing and its list start to drift apart. We work with the layout and columns you already use, so the list ties straight into the next stage of the process in purchasing or production. For companies with a lot of repetition in their components, such as piping or steel parts, that difference is greatest in practice.
Cable tray routing in the model, built with parametric families that carry the material schedule with them.
Bills of materials drawn up after a messy as-built file
For a client in greenhouse construction, we once received as-built material in which the existing drawings had been printed incorrectly and partly amended by hand. As a result, the underlying bill of materials could no longer be trusted: quantities no longer matched what was actually installed in the system, and the component numbering had become muddled. Rather than repeatedly calling the client with questions, we sorted this out ourselves, placing the drawing and its list side by side again and correcting the discrepancies one by one. We bring that approach to every project in which a client uses our bills of materials service.
First, we determine whether the existing set is still usable as a basis or whether rebuilding is quicker, because repairing a messy set sometimes takes more time than setting up a new list from the model. We then set up the link between drawing, model and list so that a change in one automatically carries through to the others. For piping systems with a lot of repetition, such as a schematic with valves in various sizes, the difference is clearly noticeable, because we build each component correctly only once.
Our experience with messy, partly manual files is precisely why we assess the state of what is supplied before the project starts. That way we avoid building on a foundation that is already wrong, and an error does not only come to light at the final check. A project lead who has doubts about their own existing list often recognises this picture, because such a list usually drifts off course gradually, after a few changes nobody kept track of.
What a bills of materials service actually delivers
When you hand us a bills of materials job, there is usually more to it than a standalone list of components. We deliver the underlying 2D drawing or 3D model the list is derived from, plus revisions as soon as we have updated an earlier version. On Revit projects, we link the list directly to the model, so quantities, dimensions and material codes update automatically as soon as someone adds or changes a component.
If you work in AutoCAD, we build the list as a standalone DWG or DXF file matched to the drawing it belongs to. For larger sets with parametric components, such as a piping system with dozens of valves in different sizes, we first build the smart component and only then link the list to it, so a later change does not have to be made by hand again. We supply STEP files and other common CAD formats when you need them for another package in the chain.
We work with the latest version of the software used and always tailor the structure to what happens to it further down the process, whether that is purchasing, production or assembly. If you only need a revision of an existing list, you get a separate, smaller project from us, whereas if you are drawing up a completely new system, you get a larger set including the underlying drawings. That scalability, from a small revision to a complete set, is why clients use us both during a peak in the drawing office and on an ongoing project, without having to change anything in their own planning.
No ongoing payroll costs and no idle staff once the peak is over. If one of our people is off sick or on holiday, we replace them and the work simply carries on.
How our bills of materials fit your process
The set we deliver contains not only the list itself but also the drawing or model it refers to, with the same numbering and the same column layout you already use. We do this deliberately, because a bill of materials that does not fit the existing way purchasing or production works only creates extra work rather than saving time. Before we start, we therefore first ask for your CAD standards and list structure, and only then do we start drafting. For a manufacturer, that can mean adopting material codes from an internal system, while for a contractor the link to a specification list is more important. We deliver the work in stages, so you can check along the way that the structure is right before we complete the whole project. That interim feedback prevents a wrong assumption from only coming to light at the final delivery.
For a greenhouse construction project, where we use software that you can log into to follow progress, we update the list directly in that environment. For standalone drafting work, files are exchanged by email, with clear version numbers so it is never unclear which list is the latest. At least three people check the list before it leaves our office: a drafter who builds it, a second who checks the quantities, and Sam, our team leader, who does the final check, so a counting error does not slip through. That combination of fitting in with the existing way of working and several review rounds makes a bill of materials usable for the team that has to work with it further down the line, whether on site or in a production hall.
Working to your CAD standards and layer structure
Every client has their own CAD standards, their own layer structure and their own conventions for naming components, and we deliberately align with these rather than imposing our own system. At the start of a project, we ask for existing drawings, templates and, if available, an internal manual with conventions. If there is no manual, we derive the standard from the existing set of drawings and only adopt it as the starting point once you have approved it.
An incorrect layer structure can cause a bill of materials to miss components or count them twice, for example when a piping layer accidentally also contains components that actually belong to another discipline.
By checking the layer structure in advance, we eliminate that risk before the work properly begins. On Revit projects, the same applies to the families we use, because a family that is not built to your standard later produces a list that raises questions internally. If we come across an existing, somewhat messy family set, we first assess whether cleaning it up is enough or whether rebuilding will lead to a reliable result faster.
That choice depends on how far the existing set has strayed from its original setup. At the end of the project, we check the delivered list once more against the original standard, so what we hand over fits seamlessly into the system you already work in and no separate conversion step is needed. That keeps the result usable, even when we pick up a follow-on project for the same client.
Frequently asked questions about our bills of materials service
Let us handle your bills of materials
Send us your documents and drawing conventions and we will let you know within one to two working days what we can take on and when.