No. Pipework is always separated by service (hot water, cold water, greywater, fire mains, gas, etc.). Each service has different pipe materials, connection details, insulation, and regulatory requirements (e.g., hot water may require insulation for energy efficiency, greywater may need distinct filtration systems). Measuring them together would cause tenderers to make assumptions about service, material, and installation, creating scope gaps and disputes during pricing and final accounts. Always list pipework separately by service, material, and where necessary, location (internal, external, underground).

No. Even if sanitary fittings are client-supplied, you must still measure them under Plumbing and Drainage but annotate them clearly as “client-supplied fittings to be fixed only”. The contractor still incurs cost in handling, protecting, installing, testing, and commissioning these fittings. If you exclude them entirely, the contractor will claim for additional preliminaries and fixing charges later. Also, ensure that fixing brackets, connections, traps, and related sundries are not forgotten — these are never deemed included with free-issue fittings unless specified.

No. Grease traps, oil separators, or interceptors are measured as distinct components. They are often proprietary items with specific installation instructions (e.g., ventilation, concrete surrounds, or external access covers). Drainage pipework simply connects to these units and is measured separately. Failing to list the grease trap as a separate item can result in contractors pricing only for pipework, leaving the actual trap unpriced or claimed as a variation.

Only the pipework and sleeves are measured under Plumbing and Drainage. The associated waterproofing, including puddle flanges, collars, or flexible seals, is measured under the Waterproofing trade unless otherwise specified. QSs often forget this separation, leading to the contractor claiming extra for waterproofing materials that were not described in the Plumbing section.

No. Support frames, ducting, and special fixing arrangements must be measured separately. These are not “deemed included” with wall-hung fittings, as they typically require structural design input and separate procurement. Fittings are measured by their functional type (toilet, basin, urinal, etc.), while the support system is either listed as part of Plumbing or sometimes under Metalwork, depending on the design approach.

They must be measured separately as underground and above-ground systems. The requirements for bedding, backfilling, access for inspection, and jointing differ. Above-ground systems may also require venting, expansion joints, and different material grades. Always split at the point where the system crosses the finished ground level, even if technically it is the same pipeline.

Definitely not. Changes in pipe material (uPVC, HDPE, cast iron, etc.) must be separately measured. Different jointing systems (solvent weld, electrofusion, push-fit) and handling methods will result in significant price variations. HDPE pipework in particular often requires welding equipment and specialist installation teams. Combining dissimilar materials into a single item will create ambiguity and pricing disputes.

No. Each type of drainage structure is measured individually. They differ in construction (brickwork, concrete, precast), purpose (inspection vs. sedimentation), and access requirements. For manholes, you must also separate them by depth bands (e.g., up to 1.5m deep, over 1.5m deep) to reflect construction effort and risk. Grouping them will not comply with SSMBW and will prevent proper tender analysis.

No. Any special protective measures (e.g., sleeves, pipe wrapping, anti-corrosion coatings) for use in contaminated ground must be measured as separate items. Standard pipework descriptions cover normal soil conditions only. Contaminated ground requirements significantly affect pricing and installation complexity, so they must be fully described and itemised.

Vent pipes are measured separately. Although they may connect directly to soil stacks or drainage runs, they require separate vertical pipework, roof flashings, terminals, and may be subject to weatherproofing considerations. If you include them under general stack pipework without clear separation, contractors may exclude or under-price the roof penetrations and flashings.

No. Pipe insulation is always measured under a separate heading, including any weatherproofing jackets or UV protection layers. The SSMBW makes it clear that insulation, like lagging or protection, is not “deemed included” unless noted. Ensure that the BoQ specifies insulation type, thickness, and protection requirements separately, especially when dealing with external runs.

Plumbing and Drainage. Submersible sump pumps, when associated with stormwater or foul water systems, are measured under Plumbing and Drainage. However, you must clearly identify them as pumps, not general drainage components, and describe associated chambers, guides, and control panels separately. Only pumps integral to mechanical systems (e.g., HVAC systems) would fall under Mechanical Work.

Everything above ground (gutters, downpipes, offsets, brackets) is measured under Roof Coverings, Claddings, etc., while anything below ground (stormwater pipes, manholes, soakaways) is measured under Plumbing and Drainage. The transition is usually at ground level or the point where the pipe enters the ground. This is a classic tender query issue, so always make the split clear in your BoQ.

This is clearly an Alteration. Even if you replace old pipes with new during the diversion, the purpose is to modify an existing system, not install new work. Measure it under Alterations, with a clear description of the scope (break out, remove, divert, reinstate). Avoid slipping this into the new plumbing section, as it will complicate variation valuations.

No. Testing is a distinct activity and must be measured separately. Pipework measurement covers supply and installation only. Testing (hydraulic, air, or vacuum) requires specialist equipment, additional time, and certification and is thus a separate cost item. If left unmeasured, the contractor will almost certainly seek additional payment later.

On one of our mixed-use buildings, the engineer has designed the fire hose reels to be fed directly from the domestic cold-water system instead of a dedicated fire line. The contractor is insisting this is part of the plumbing scope, not the fire services.

Do we measure the pipework for hose reels under Plumbing and Drainage or Fire Protection? The line branches off after the bulk water meter.

Despite the hose reels being fed from the domestic cold-water system, any installations that serve a fire protection function must be measured under Fire Protection Services, not under Plumbing and Drainage.

SSMBW Plumbing covers the water supply for domestic and sanitary use. Hose reels—even if supplied from the same pipework—fall under life safety and should be treated separately for compliance and maintenance accountability.

Clarify in the BOQ and Preliminaries that the water source is shared, but measurement and costing for hose reels must align with Fire Protection requirements.

We're being asked to install 50mm floor drainage pipes within post-tensioned floor slabs. The pipes must be sleeved and coordinated before stressing. The QS is unsure how to price this and whether the sleeves and protection are part of the pipe rate.

Is there a standard approach to measuring these embedded pipes? Should sleeves and coordination be listed separately?

Plumbing pipework embedded within post-tensioned slabs must be measured separately from standard above-ground or below-ground piping, and the sleeving, boxing, or protection required for slab integration must also be separately itemised. The SSMBW allows for special descriptions and items where work is embedded, coordinated with structure, or includes special procedures. You should:

• Measure the pipe as a separate line item (‘laid in post-tensioned slab with sleeving’),
• Measure the sleeves separately (by type or size), and
• Include coordination notes in the Preliminaries or a Provisional Sum for layout adjustments.

We’re on a commercial kitchen project where the grease traps are located under a raised access floor, not below ground. The traps are above a suspended slab, and maintenance access is via floor hatches.

Should these be measured under below-ground drainage, or as part of above-ground waste systems? And does the trap connection count as a fixture?

Since the grease traps are installed above structural slab level—even if below raised access floors—they are classified as above-ground drainage for measurement purposes. They must be measured under waste systems, not under below-ground drainage.

The grease trap itself should be listed as a fixture or proprietary unit, including:

• Its inlet and outlet connections,
• Maintenance access cover or hatch,
• Venting (if any).

Clarify in the BOQ that the trap is not buried, and ensure proper coordination with floor detailing, waterproofing (if required), and load-bearing support.

This building uses a greywater recycling system where wastewater from showers and basins is collected, filtered, and reused for WC flushing. There are two separate pipe systems: one for greywater collection, and another for its redistribution.

How should we measure these pipe systems? Can they be grouped under one ‘greywater system’ item, or must they be split into collection and supply systems?

Each pipe system in a greywater setup must be measured based on its function—not grouped into a single system item. You should split the works as follows:

• Greywater collection pipework (from basins, showers) must be measured under wastewater drainage
• Greywater redistribution pipework (to WCs or irrigation) is a non-potable supply system and must be measured under cold water supply

The BOQ must also describe the treatment unit, holding tanks, and filters separately if these are contractor-supplied. Coordination between plumbing and specialist system installers must be described in Preliminaries.