No. Where glazing forms part of a proprietary system (e.g., shopfronts, curtain walls, structural glazing systems), it is deemed included within the supply of that system and is not measured separately under Glazing. However, if the glazing is inserted separately into timber, steel, or aluminium frames not supplied by a proprietary system, it must be measured separately under the Glazing trade. Be careful: shopfronts ≠ loose glazing.

It is deemed included within the double-glazed unit but must be explicitly described in the BoQ. Tenderers will price based on the BoQ description, so if you merely say “double-glazing” they may assume a basic air-filled unit without coatings, leading to disputes. The BoQ should specify glass thickness, coating type, cavity treatment (e.g., argon-filled), and spacer bar if performance is important.

Definitely not. Fire-rated glazing must be measured separately. It differs from standard glazing not only in material and installation requirements but also in the need for certification, testing, and sometimes specialist framing. The BoQ must clearly state the rating (e.g., 30-min, 60-min integrity and insulation) and the relevant standard (e.g., SANS 10177) to avoid contractors pricing for non-compliant glass.

No - but it must be fully described within the glazing item. Decorative finishes (sandblasting, screen-printing, acid-etching, ceramic frits) are not measured separately but significantly affect price and production. Always describe the finish clearly in the BoQ or allow a separate rate item if the pattern varies significantly between panels.

Glazing forming part of rooflights or skylights is measured under Roof Coverings, Claddings, etc. as per SSMBW. Only glazing within windows, doors, and interior partitions is measured under the Glazing trade. Rooflights are treated as part of the weatherproofing and structural envelope and not as standalone glazing.

No. Wired glass is always measured separately. It is a specialist glass used for security or fire protection and cannot be treated as standard float glass. It is heavier, more difficult to cut, and may have installation restrictions, particularly where it forms part of a fire-resisting assembly. Clearly identify wired glass, its location, and any performance rating required.

No. Glass thickness is a specified performance parameter, not merely a supply detail. Reducing glass thickness without formal design team approval constitutes a variation and could compromise structural performance, acoustic insulation, or compliance with SANS standards. Always verify that proposed substitutions meet project performance requirements before accepting any changes.

Mirrors are typically measured under Glazing, particularly when they are permanently fixed to walls. However, if they form part of bathroom accessories or loose furniture (e.g., framed mirrors supplied by the interior designer or part of bathroom cabinets), they may appear under Fixtures & Fittings. Always confirm with the specification and client schedules. For BoQ purposes, fixed mirrors are generally Glazing.

Thermally broken spacers form part of the double-glazed units and are not measured separately, but you must clearly include this requirement in the glazing description. The contractor will not allow for thermally broken spacers unless clearly specified, as they are not part of the standard double-glazed unit make-up.

Yes. Performance testing, such as on-site impact testing for SANS compliance, must be measured as a separate item under Glazing. The supply and installation of glass do not automatically include testing unless stated in the preambles. Where certification, mock-up testing, or on-site verification is required, you must allow for it specifically.

Yes - the performance requirement must be clearly included in the description of the glazing. Contractors will only allow for performance coatings, special interlayers, or glass make-ups if stated explicitly. Leaving it to the specification alone risks under-pricing, especially as SHGC-compliant glass tends to cost more than standard options. This information should be communicated by the Architect.

No. Glass thickness and type are performance-critical and cannot be substituted without formal approval. Thicker or toughened glass is often specified not because of loadbearing requirements but for impact resistance, acoustic performance, or code compliance (e.g., SANS 10400). Contractors may argue cost-saving, but accepting this without full approval and a formal variation exposes the project to safety risks and legal non-compliance. The BoQ and specification should be treated together to determine what was priced, and what is required.

No. Applied films (solar, security, privacy) are measured under Fittings & Fixtures or sometimes Sundries, not under Glazing. The Glazing trade deals only with the glass itself and integral factory-applied coatings. Site-applied films are a finishing operation. Many candidates miss this, especially when the client requests it post-tender, leading to confusion about who is responsible.

This is treated as a substitution, not an omission. Even though the Glazing subcontractor was not yet appointed, the original BOQ and design intent included the fire-rated glazing, which formed part of the priced tender. Replacing it with non-fire-rated glazing alters the specification, not just the quantity. The scope of work remains, but the performance requirement changes.

This is not a pure omission, because glazing is still being installed—it’s simply being downgraded in terms of fire rating. Therefore, the valuation should reflect a credit for the higher-spec item (fire-rated glazing) and a cost for the substituted, lower-spec item (standard glazing), in line with typical substitution principles.

Glass block walls should be measured under Glazing but clearly described as “glass block masonry” or “solid glazing units.”

They are measured by area of wall (m²), not by number of blocks. Reinforcement and mortar bedding should be included in the rate unless otherwise specified.

They do not fall under Masonry because they are non-load-bearing, and not under Finishes because they constitute the actual wall structure rather than a cladding.

No. Door hardware is measured under Ironmongery, not under Glazing. Glazing to doors, shopfronts, or partitions includes the glass and its fixing, but never the door furniture unless it forms part of a proprietary. Separate measurement is essential as ironmongery affects fire compliance, security, and accessibility — and it is priced by a different specialist.

A heritage building we’re restoring has timber-framed windows, and the Architect is retrofitting double-glazed units into these existing sashes. The timber frames are being repaired by a joiner, but the glazing is new.

Do we measure the double-glazing as normal glazing, or do we need to account for the reuse of frames?

The double-glazed units themselves are measured under Glazing. The reuse of timber frames does not change the classification of the glazing, but it must be noted in the BOQ description that the units are “retrofitted into existing or refurbished joinery.”

The timber repairs are measured under Joinery, and any specialist installation procedures—such as re-beading, bedding compounds, or non-standard sealants—can be described or allowed under Dayworks or a provisional item.

Do not include the glazing into the joinery rate unless the frame and glass are supplied as one unit.

Our washroom specifications call for obscure glazing in high-humidity areas. The Architect insists this should also be safety-rated glass due to its position above baths and in changing cubicles.

Is this a glazing item or a specialist safety item? And should the obscure finish be described separately from the safety spec?

This should be measured as a standard Glazing item, with the description clearly stating that the glass is:

• Obscure (e.g., sandblasted, patterned, frosted),
• Safety-rated (e.g., toughened or laminated), and
• Located in wet areas or above sanitary fittings.

While the safety requirement affects the glass type, it does not shift the item to a different trade. However, the combination of finishes (e.g., toughened + obscure) must be explicitly described, and costed accordingly due to processing differences.

If the obscure finish is a film or applied post-installation, it may be measured as a separate item or under Fixtures.

I’m measuring a small commercial project that includes aluminium-framed windows, sliding doors, and shopfronts—all glazed, proprietary units. Now I’m stuck. Should I measure these under Glazing, since they obviously include glass, or under Metalwork, since they’re aluminium systems? I don’t want to split the item across two trades, but I’m not sure what’s correct.

You're not alone—this is one of the most debated grey areas in the Standard System, and the answer lies in balancing the letter of the Standard with practical industry norms

Technically speaking, the SSMBW does allow for proprietary glazed systems—including frames, beads, fixings, etc.—to be measured under Glazing. However, in practice, most Quantity Surveyors measure proprietary aluminium-framed units (like windows, sliding doors, or shopfronts) under the Aluminium / Metalwork trade. That’s because:

• These units are usually designed, supplied, and installed by a specialist aluminium subcontractor.
• The cost and complexity sit more with the aluminium framing system than the glazing itself.
• The items come as a complete unit, and QSs prefer to keep the full value in one trade - especially for valuation and subcontractor package clarity.

Rule of thumb:

• Measure complete aluminium-framed glazed units under Aluminium / Metalwork.
• Measure loose glazing or frameless glass installations under Glazing.

And no - don’t split the item across trades. It creates scope confusion, double-counting risks, and chaos in tender returns. Choose the most appropriate trade for the nature of the item - and stick to it consistently throughout the BOQ.

We’ve got clerestory windows specified in a double-volume atrium. The windows are clearly shown on the drawings, but due to their position (8m up), the contractor is now claiming for additional costs related to scaffolding, lifting gear, and specialist installers. They argue that because the BOQ didn’t mention the installation height, they’re entitled to claim this separately. Is this valid? Should installation height be deemed included?

Under the SSMBW, unless stated otherwise, access and installation method are deemed included in the BOQ rate. The contractor is expected to allow for typical working conditions associated with each item. The Glazing trade does not make separate provision for installation height. If the windows are shown on the drawings and clearly positioned high up, the contractor is deemed to have priced accordingly. The only time a separate claim could be justified is if:

• The installation method was not reasonably inferable from the drawings, or
• The detail was omitted or unclear, or
• An instruction materially changed the method of access.

So, unless the Principal Agent issued a new instruction altering access conditions, or the drawings were misleading, this is not a valid additional claim. High-level glazing? Priced risk.