When you bring in a BIM modeller on a project basis, you want to know who looks at the work before it leaves the building. With us, every piece goes through at least three review layers. A drafter produces the model or drawing, a second team member checks that work, Sam, our team leader, then reviews it and Barry, our project manager, gives it a final check.
That sequence is fixed, even when the schedule is tight, because an error that only surfaces on site costs many times more than half an hour of checking.
In practice, that keeps the number of errors to a minimum. We draft and model; we do not do engineering or structural calculations. Our team works remotely from our own office, with our own licences and always on the latest versions. With our large, flexible team, we scale up or down per project. We respond to enquiries within 1 to 2 working days and then talk the project through with you.
Cable tray routing in the model, built with parametric families that carry the material schedule with them.
Parametric BIM work and smart families
For us, parametric modelling means a component adapts rather than being redrawn from scratch. We build Revit families, in other words smart components, that follow along with a different size or a different situation. We create the component properly once, after which it can be placed anywhere without anyone having to redraw it. The material schedule is built in, so when the component changes, the schedule updates automatically. A project leader notices the difference mainly in revision rounds, because that is normally where most of the manual work sits.
The best-known example from our practice comes from greenhouse construction, where companies often work in AutoCAD. AutoCAD is not smart when it comes to building up components such as valves in piping systems. If you need a valve in 90 and in 110, you redraw it by hand every time. With a smart family it is in place in a single step, and in that kind of work it saves at least seventy per cent of the time. On a project basis this is attractive, because the investment in the family pays for itself within the same project.
That is why we look at the start to see which components recur often enough to justify that step. If something appears twice, we simply draw it. If it appears forty times in varying sizes, we build it parametrically. We can clean up existing families or rebuild them, depending on the state of the set. If a family set is very messy, rebuilding is sometimes faster than repairing, and we present that trade-off with a short rationale. We use Grasshopper, and to a limited extent Dynamo, wherever repetition can be automated.
Software and formats in which we deliver BIM models
Our main software is Revit, AutoCAD and Rhino, and we also work with Inventor, Grasshopper and, to a limited extent, Dynamo and Vault. We always run the latest versions and work in our own environment with our own licences. We leave the client's environment alone, which can save them effort on administration, access and licences. What we do adopt in full is your CAD standard. We take layers, naming, title blocks, line weights and sheet structure from the set you supply or from the manual you send along.
File formats are rarely a problem, as we deliver in DXF, DWG, Revit formats and STEP, and in practice in any common CAD format. For exchanges with machine builders or suppliers, STEP is often the most practical, while an architectural set usually stays in DWG. For project-based work, we agree in advance which version is leading. Otherwise, a set that moves to a newer Revit version halfway through costs needless conversion rounds. At the start, we also check whether the files supplied are complete, including linked references and the families used.
If anything is missing, we flag it straight away rather than making an assumption. We use Rhino where the shape is more complex than a standard architectural model can handle. Inventor comes into play for components that originate from mechanical engineering. We decide together with the client in the first meeting which route gives the best chance of a clean set. We record that choice, so there are never two versions of the truth later on.
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.
What a BIM modeller on a project basis delivers
On a project basis, we deliver a finished set rather than loose hours. It starts with the model, in which we set up building elements, levels and zones according to the client's breakdown. From that we produce floor plans, sections, elevations, typical details and the associated schedules. In 2D, we deliver complete AutoCAD sets, from overview sheets to detail sheets and piping diagrams. As-built drawings are a separate part of our work, where we turn the material supplied into a single up-to-date, legible set. We handle revisions round by round and keep track of them, so you can trace later which change ended up where. We deliver 3D modelling in Rhino where the geometry calls for it, usually exchanged via STEP or DWG. Families and templates are also part of the output, as they remain usable in your drawing office after the project.
We deliver in stages, at a pace that matches the meeting schedule we have agreed. For one-off drafting work that happens by email; for larger projects, via software you can log into to follow progress. Every stage includes the source files, not just an export or a print. Intellectual property rights to our work rest with the client. We are also clear about what falls outside our scope. We do not do calculations, give structural advice or handle permits. Our part is drafting and modelling, and we deliver it complete and in line with the existing set. At the start of the project, we record on a single list exactly what the delivery includes.
Three review layers on every drawing
Checking starts during drafting, not at delivery. A drafter hands in a block of work, after which a second team member checks it for dimensioning, layer structure and consistency with the rest of the set. Sam, the team leader, then reviews it with the eye of someone who has worked in architecture for more than fifteen years and still works as an engineer.
He focuses mainly on how the sheets work together and on whether the model matches what construction needs to do with it. Barry gives it a final check before any stage goes out. That may seem like a lot of checking for drafting work, but it prevents exactly the errors that arise in volume.
A wrong hatch that creeps onto one sheet is on thirty sheets a day later. We catch deviations like that early by delivering in stages and getting feedback straight away. On an as-built dossier for Firefly, the existing drawings had been printed incorrectly and were partly drawn by hand. That material was hard to read and messy, and we sorted it out ourselves instead of constantly calling the client. That approach calls for extra checking, because our own interpretation has to be right.
That is why such decisions always passed several pairs of eyes before we delivered. Even under time pressure, we keep the layers in place, because rushed work without checks only leads to an extra round. Together, the core of our team brings around twenty-five years of experience, and everyone who works for us has more than ten years of CAD behind them.
Frequently asked questions about a BIM modeller on a project basis
Hand your BIM project over to us
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.