Material Samples and Approvals: Getting Sign-Off Before Ordering
The material approval process is how a contractor submits each material, as a physical sample, data sheet or shop drawing, for the client's design team to approve before it is ordered. A submittal register tracks each item against the date it must be ordered. Approvals given late consume lead time, and approved samples are kept as the benchmark that deliveries are checked against.
By Dhruv Agarwal · · 6 min read
Finishes are approved late far more often than they are built late
Ask why a fit-out missed its date and the answer is often a delivery: the stone arrived late, the glass partitions were still in the factory, the carpet came in the wrong shade. Trace it back and the cause is usually earlier. The item was ordered late because it was approved late, or approved, ordered and then changed.
The misconception is that sample approval is a design formality that happens somewhere in the background while the site gets on with work. It is not. An approval is an activity on the critical path whenever the item has a long lead time. Every week spent deciding between two veneers is a week taken from the supplier's manufacturing time, and the site cannot recover it by working harder.
The cost of getting this wrong goes beyond time. Finishes approved in a hurry, from a small swatch under office lighting, are the ones that look wrong when they cover a whole floor, and a change at that stage is paid for twice: once for the material ordered, once for its replacement.
What gets submitted, and why
| Submittal type | What it shows | Best used for | What it cannot tell you |
|---|---|---|---|
| Physical sample | Colour, texture, pattern, finish, feel | Stone, tile, laminate, veneer, fabric, carpet, paint, metal finishes, glass tint | Fire, acoustic or durability performance |
| Range sample | The expected variation across the supply | Natural stone, timber, handmade or glazed tiles | How a specific batch will look |
| Product data sheet | The manufacturer's stated properties and dimensions | Every specified product | Whether the actual delivery matches it |
| Test reports | Performance against a named test standard | Fire classification, acoustic rating, emissions, slip resistance | Appearance |
| Shop drawing | How the item will be made, fixed and jointed | Joinery, partitions, ceilings, metalwork, glazing | Finish quality |
| Mock-up | The assembled result at full size, in place | Typical rooms, feature walls, facade bays | Performance across every condition |
Most items need more than one. A partition system needs a shop drawing, a data sheet, test reports for any fire or acoustic rating claimed, and a sample of the finish. Where the combination of finishes matters as much as each one, a mock-up room before the full fit-out shows the result before it is repeated across the floor.
The submittal register turns approvals into a programme
A submittal register lists every item needing approval and works backwards from the date it is needed on site:
- Need-on-site date, from the construction programme.
- Minus the lead time: manufacture and delivery, confirmed with the supplier.
- Minus the review period: the time the design team takes to review and return a submittal, agreed in the contract.
- Minus time for one resubmission, because not everything is approved first time.
That gives the latest date each submittal must go in. The register then records the date submitted, the reviewer, the status returned (commonly approved, approved with comments, revise and resubmit, or rejected), and the revision. Reviewed weekly, it shows which approvals are about to cost time before they do. How approvals sit alongside design freeze and long-lead ordering in the overall sequence is covered in office fit-out programme: where the time actually goes.
Quality management guidance treats this as planned control, not paperwork. IS 15883 (Part 4) gives guidance on quality management for construction projects, and ISO 10005 on preparing quality plans, which is where the submittal and inspection procedure for a project is usually set out.
Who approves, and what "approved" means
Approvals stall most often not because the review is difficult but because nobody is clearly authorised to give it. A finish circulated to a committee by email collects opinions, not decisions. Three arrangements make the process work.
One named approver per category. The design team reviews against the specification; a single person on the client side signs off appearance and brand items. Others can be consulted, but the register shows one name.
A clear status, not a conversation. "Approved with comments" is useful only if the comments are specific and the contractor knows whether to order. Where a comment changes the product, the item should be resubmitted, not ordered on an interpretation.
Decisions recorded where everyone can see them. The register, the signed sample and the returned submittal should all carry the same status and date. When an approved item is later questioned, the record shows what was approved, by whom and against which revision of the specification.
Clients sometimes worry that a formal process slows things down. In practice it is the informal one that does: approvals given verbally on site are revisited later, and the item is reordered.
Physical samples: judge them the way they will be seen
A swatch on a meeting room table is a poor guide to a floor finish. Some practical rules from site:
- Ask for samples large enough to judge. Pattern, veining and texture are invisible on a small chip.
- View them in the room's light, daylight and artificial, at the distance they will be seen from. Colour temperature changes how finishes read.
- Review finishes together. Floor, wall, joinery and fabric samples on one board show clashes that separate approvals miss.
- Approve against the specification, not just the look. A beautiful sample without the test report for its fire or slip classification is not approved.
Performance properties need documents, not eyes. Whether a product's fire or acoustic classification suits a particular location is for the project's designer and consultants to decide; the approval should confirm that the submitted test reports match what they specified.
Approved samples, batches and shade
Once approved, a sample becomes the benchmark for the project. Label it with the item, specification reference, date and approver's signature, and keep sets in at least two places, typically on site and with the designer. Deliveries are checked against it before fixing, not after.
Batch variation is the other half of the problem. Tiles, stone, carpet, laminate, paint and even light fittings vary between production runs:
- Order from one batch where possible, including an allowance for wastage and a reserve for future repairs.
- Record batch numbers on delivery notes and check them on arrival.
- For natural stone, approve a range sample showing acceptable variation, and agree how slabs will be laid out before cutting.
- For carpet, dye lots differ; the same applies to carpet tile ordered in stages.
A material substituted after approval, for availability or price, should go through the same approval again. If it is a change the client asks for, it is usually a variation, for the reasons set out in why a change costs more after contract.
Common mistakes
- Leaving finish selection open after design freeze. Long-lead items wait on a decision nobody has scheduled.
- No submittal register. Approvals live in email threads and nobody sees the backlog.
- Approving from a small swatch under the wrong light.
- Approving appearance without performance. The sample looks right; the test report is missing.
- Not retaining the approved sample. A shade dispute comes down to memory.
- Mixed batches on one floor. Two deliveries, two shades, one visible line.
- Accepting substitutions informally. A "same as approved" product arrives without anyone approving it.
What to ask your design team and contractor
- Is there a submittal register, and does it work back from need-on-site dates?
- What review period does the contract allow, and who is the named approver?
- Which items need physical samples, which need test reports, and which need both?
- Where will approved samples be kept, and who signs them?
- How will batch numbers be recorded and checked on delivery?
- How are substitutions proposed and approved?
Standards referenced
Quality management guidance for construction projects in IS 15883 (Part 4); guidance on quality plans in ISO 10005; construction management and practices in NBC 2016, Part 7. The specification, required performance classifications and acceptance criteria for any material are set by the project's designers, engineers and consultants, and the manufacturer's data governs each product's properties.
Standards referenced
- IS 15883 (Part 4) — Construction project management - guidelines - quality management (Bureau of Indian Standards)
- ISO 10005 — Quality management - guidelines for quality plans (ISO)
- NBC 2016, Part 7 — Construction management, practices and safety (Bureau of Indian Standards)
Frequently asked
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