Plumbing systems are deceptively difficult to coordinate. On plan, hot and cold water pipework, sanitary drainage, stormwater, and gas lines each occupy their own drawing set. In the building, they all share the same wall cavities, ceiling voids, and floor zones — competing for space with structural elements, mechanical ductwork, and electrical containment at exactly the same locations.
We build plumbing models in Autodesk Revit to the LOD required at each project stage. Our scope covers:
mains supply, storage tanks, boosted cold water distribution, and branch pipework to all draw-off points
calorifier or HIU connections, hot water distribution, secondary returns, and trace heating where specified
Soil and waste pipework modeled with correct gradients per BS EN 12056 and BS EN 752,stack arrangements, and access points
gutters, downpipes, underground drainage, and attenuation connections modeled to the drainage strategy
incoming main, meter installation, and distribution pipework modeled with separation requirements from electrical systems
where specified in the sustainability brief, harvesting tanks, pumps, and distribution pipework are incorporated
pipework to boilers, heat pumps, heat interface units, and associated valving modeled with maintenance clearances
The most common plumbing coordination failures on UK residential and commercial projects share a pattern: drainage stack positions are fixed early in the design based on floor plan logic, but nobody checks the structural implications until the concrete frame is cast. Once cast, relocating a stack penetration means coring — which adds cost, structural risk, and programme delay.
The second common failure is hot water secondary return routing. Secondary returns need to be short to maintain temperature and meet Legionella control requirements under CIBSE CP1 and HSG 274. Long routes driven by uncoordinated ceiling layouts increase both heat loss and compliance risk. A coordinated plumbing model identifies these issues before the ceiling design is fixed.
We address both problems through early model development. Stack and drain positions are coordinated against the structural model as soon as slab layouts are available. Secondary return routes are checked against ceiling height and travel distance from the outset, not after mechanical and electrical have claimed the ceiling space.
A structured, repeatable process that gives every project a clear path from model intake to signed construction release.
We receive design drawings, drainage strategy, and plumbing specification. We confirm LOD requirements, applicable standards (BS EN 806, WRAS, BS EN 12056), and the federated model environment.
Soil and waste stacks are modeled first and coordinated against structural elements and slab penetrations. Drain gradients are set and checked against available ceiling heights on every run
Hot and cold water distribution is modeled with pipe sizing from design calculations, insulation thicknesses, and valving arrangements for isolation and maintenance.
Gas pipework and specialist systems are modeled with statutory separation distances and ventilation requirements per IGE/UP/2 and BS 6400.
The plumbing model is combined with mechanical, electrical, structural, and architectural models in Navisworks. Hard clashes, clearance clashes, and gradient conflicts are all identified.
Conflicts are resolved through coordination meetings, with agreed solutions confirmed in the model. Coordinated drawings are issued per zone with pipe levels, gradients, and sleeve positions.
For complex pipework and plant rooms, isometric drawings are produced directly from the Revit model to support fabrication and installation.
Yes — and this is a core part of what makes plumbing BIM useful. We model all soil and waste pipework with gradients set to the requirements of BS EN 12056 and the project specification. In Revit, gravity drainage elements carry slope data that we check against available ceiling voids and structural constraints. Where a gradient conflict exists, we identify it in the coordination model and raise it before it becomes a site problem.
Yes. Cold water systems are modeled with WRAS-compliant materials and layouts. Secondary hot water returns are checked against CIBSE CP1 Legionella control guidance for dead-leg length and return temperatures. Where the design does not meet these requirements, we flag it in the coordination record for design team review.
Yes. Gas supply pipework is modeled with the separation distances from electrical systems required under IGE/UP/2 and BS 6400. Gas meter locations and service entry points are coordinated against structural, architectural, and electrical models to confirm compliant installation positions.
Plant rooms are typically the most densely serviced areas on any project and receive priority coordination attention. We model plant room pipework with full equipment clearances, maintenance access zones, and valving arrangements before coordinating with mechanical plant, electrical distribution, and structural supports. Plant room coordination drawings are issued as a separate package from the wider floor-by-floor coordination.
Coordination drawings are issued as PDFs for review and AutoCAD DWG for contractor use. The Revit model is delivered in the native file format at the agreed LOD. We can also export to IFC where required by the project BIM protocol.
