Your contractor says it is within tolerance. Whose tolerance? What CIDB's QLASSIC standard is, what it does not cover, and how to agree a yardstick before the work starts.
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In a renovation, a defect is work that falls short of a yardstick you and the contractor can both point to: your contract and drawings, the product maker's installation instructions, or a published workmanship standard such as CIDB's QLASSIC standard, CIS 7. QLASSIC itself scores finished building projects before handover, so it rarely applies to a home renovation directly, but its method of checking each element against written criteria is the right model. Agree the yardstick before work starts. To have the finished work checked in the Klang Valley, see renovation inspection.
Most renovation arguments are not about whether something looks a little off. They are about whether it is bad enough to be redone at the contractor's expense. An owner sees a tile edge that catches the light; the contractor says every floor has that. Both may be sincere. Without a reference point agreed in advance, the conversation turns into opinion against opinion, and the person holding the money usually loses patience first.
A tolerance is simply the amount of variation the parties accept as normal. Nothing built by hand is perfectly flat, plumb or square, so every trade works to some allowance. The question that settles a dispute is which allowance applies to your job, who wrote it down, and whether the finished work is inside it. That is why this guide spends more time on where tolerances come from than on any single figure.
QLASSIC stands for the Quality Assessment System for Building Construction Works. The Construction Industry Development Board describes it as a system or method to measure and evaluate the workmanship quality of building construction work, based on its Construction Industry Standard CIS 7. Assessors inspect samples on site, award marks where the workmanship complies with the standard, and add the marks up into a QLASSIC Score expressed as a percentage, so that projects can be compared on one scale.
Two features of the scheme matter for owners. First, CIDB says the assessment uses the principle of first time inspection: construction works that are rectified after an assessment will not be re-assessed. Second, CIDB says the assessment is conducted after completion of the building works and before the completed project is handed over. Its categories run from landed housing and stratified housing to public and commercial buildings. In short, QLASSIC is a scheme for scoring whole projects, usually a developer's, at the end of construction.
The criteria an assessor applies live in CIS 7, not on the QLASSIC web page. CIDB's QLASSIC page says CIS 7:2014 is an improved and updated version of the CIS 7:2006 standard, while CIDB's list of industry standards now shows a CIS 7:2021 edition, sold as an English-language publication. The same listing notes that the standard was built with reference to CONQUAS, Singapore's construction quality assessment system.
Because the standard is a priced document, the numbers inside it are not something to take from forums or screenshots. If you want the QLASSIC standard to govern your renovation, buy the current edition from CIDB, or ask your contractor to name the edition and clause they will work to and attach the relevant pages to the contract. A clause that only says "to QLASSIC standard" leaves both sides to guess which elements and which edition were meant.
Owners sometimes hear that their condo scored well under QLASSIC and assume the renovation should match. The score belongs to the developer's original construction, sampled across the project before handover. It says nothing about a kitchen rebuilt years later by a different firm, and the scheme's own rule that rectified work is not re-assessed shows it was designed as a one-off snapshot, not an ongoing check.
Equally, a contractor saying they "follow QLASSIC" is a statement about method, not a promise about your unit, unless the contract says so. Treat it the way you would treat a claim about any standard: ask for it in writing, tied to specific elements such as floor tiling, wall plastering and painting, with the edition named.
In practice, renovation workmanship is judged against a stack of references. The higher a reference sits in this table, the harder it is for either side to argue with:
| Yardstick | Where you find it | How much weight it carries |
|---|---|---|
| Your signed contract and drawings | The quotation, specification and any attached drawings | Strongest: it is what both sides agreed for this job |
| A standard named in the contract | For example a stated edition of CIS 7, with the elements listed | Strong, but only for the elements the contract names |
| The maker's installation instructions | Data sheets for tiles, adhesive, boards, paint and flooring | Strong for that product: a maker can refuse a claim if its instructions were ignored |
| Ordinary trade practice | What a competent tradesperson would normally produce | Useful, but this is where most disagreements start |
| How it looks to you | Your own eye in normal light | Weakest on its own; pair it with one of the above |
The fourth row is not as vague as it sounds. Under section 53 of the Consumer Protection Act 1999, services supplied to a consumer carry an implied guarantee that they are carried out with reasonable care and skill. What counts as reasonable for a given finish is a question of fact, and whether the Act applies to your contract is a legal one; check with the Tribunal for Consumer Claims or a lawyer before relying on it.
You will find millimetre figures for tile lippage, wall flatness and door gaps quoted across the internet, often without saying where they came from. Some come from overseas standards, some from one product maker's instructions, and some are rules of thumb. Quoting one here as if it were the Malaysian rule would give you a number that may not be in your contract, may not apply to your product, and may not survive the first reply from your contractor.
The safer route is to collect the figure that actually binds your job: the one in the CIS 7 edition you attach, in the maker's data sheet for the tile or board you chose, or in your contract's specification. If none of those gives one, ask the contractor to state the tolerance in writing before the trade starts. A contractor who works to a figure will usually give it; one who will not is telling you something too.
Whatever the figure, the method of checking is much the same across standards. CIDB's assessor course itself covers sampling, site assessment and the use of measuring tools. For a home, the common checks look like this:
| Element | What is looked at | How it is checked |
|---|---|---|
| Floor and wall tiles | Hollowness, lippage between tiles, joint width, alignment, cuts at edges | Tapping each tile, a straightedge across joints, a tape for joint widths, a string line along rows |
| Plastered and skimmed walls | Flatness, cracks, corners, surface texture | A long straightedge in several directions, a torch held flat to the wall |
| Paintwork | Even coverage, brush marks, drips, cutting-in at edges | Looking along the wall in raking light |
| Ceilings | Board joints, sag, straight edges at cornices and downlight cut-outs | Sighting along the ceiling from a corner, a level on the edges |
| Doors and built-ins | Gaps, swing, alignment of doors and drawers | Opening and closing every leaf, a level on the frame |
| Wet areas | Falls to the floor trap, sealant lines | Running water and watching where it goes |
The trade-by-trade guides go further, starting with the tiling workmanship check and the painting workmanship check. If you are judging finishes on a home bought new from a developer instead, the guide to finish defects at vacant possession covers that situation.
The cheapest time to settle what counts as a defect is before the first payment. A short clause does most of the work:
The renovation contract guide covers the rest of the agreement, and the guide to checking a contractor's CIDB registration explains what that registration does and does not tell you about quality.
Some items will sit right on the line. A sensible way through is to sort each finding into one of three groups: clearly outside the agreed allowance, clearly inside it, and arguable. Ask for the first group to be fixed, drop the second, and for the third, decide which matter to how you use the room. A slight step between two tiles under a sofa is not worth the same fight as one in a doorway where people walk barefoot.
Write each item down with its location and the yardstick it is measured against, rather than "tiles uneven". The guide on how to write a defect list shows the format. Remember the QLASSIC lesson: rectified work deserves a second look, because a quick repair over a hollow tile can hide the problem without solving it.
Workmanship tolerances are about finishes and fit. They do not answer whether an electrical installation is safe or whether a structural change is sound. You can note what you see, such as a light that flickers or a crack that keeps growing, but the judgement belongs to specialists. Any repair or change to the electrical installation must be done by an electrical contractor registered with Suruhanjaya Tenaga. A crack, sagging beam or removed wall that may affect the structure needs a professional engineer's assessment.
For homeowners in KL, Selangor and Putrajaya we offer a third-party inspection of your contractor's work; if you want, we can also quote the repairs. We walk the works against your quotation, drawings and materials list, room by room, and we go through what we found with you, item by item, so you can decide which ones to raise with your contractor.
This page is general guidance, not legal advice. It quotes no tolerance figures; take those from the standard, product data sheet or contract that applies to your job.
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