The Last Day You Can Order the Windows and Still Fit Them in Week Six

Six weeks out, and nobody has an order number

The programme says windows in week six. The scaffold is booked to come down in week eight, the plasterer has pencilled week nine, and the whole back half of the job hangs off the building being closed. Somewhere in March the fabricator said eight weeks on the phone and everybody wrote it in their heads. What nobody has is an order acknowledgement, a delivery week in writing, or a deposit that has actually left an account. The job is not late yet. It is being run on a memory of a conversation, which is a different thing from a schedule and behaves worse under pressure.

The useful question is not when the windows will turn up. It is the last date the order can be placed without the job stopping — one date, on a wall, that everybody can see. That date is a subtraction, it takes an afternoon with a phone and a calendar, and hardly anyone does it, because the only term in the subtraction most people ever ask for is the manufacturing lead time, and on a made-to-order item the four around it routinely add up to more than anybody allowed for. This page publishes no lead times, no survey turnarounds and no expedite premiums, because every one of those belongs to a particular supplier in a particular month. What it publishes is the arithmetic and the questions that fill it in.

Five intervals sit between a decision and an item in the opening

Work backwards from the moment the fitter needs the item in his hands, and five separate periods appear. Only one of them is what the trade calls the lead time. The other four are unquoted, sit in four different people's diaries, and are where a fortnight quietly goes missing on nearly every job that overruns for procurement reasons.

Do the pass in that order rather than forwards, because a forward pass answers a question nobody asked. Counting forwards from today tells you when the item will arrive if you order this minute, which is interesting and not actionable. Counting backwards from the fix date produces a deadline, and a deadline is a thing a builder can hold a client to when the client wants another week to think about the colour.

One discipline makes the whole exercise honest: every interval has to come from somebody who will be held to it, and it has to arrive in writing. A number remembered from a phone call is not evidence, and neither is a website's stated dispatch time for a stock line when what you are buying is made to a survey. Ask for each period in an email, keep the reply, and put the date it was given beside it — because an interval quoted in March against a March order book is not the same interval in July.

1. Write the fix date: the day the item has to be physically in the opening, unwrapped and checked, with the fitter standing next to it. That is not the day the trade is booked; it is at least a day earlier, and on anything craned in it is earlier still.
2. Take off the receiving allowance. Something has to be offloaded, inspected, moved to where it will stand and looked at closely enough that a cracked unit is found while the lorry is still there rather than in week nine.
3. Take off transit — from the factory gate to your kerb, including whatever the haulier's delivery-day granularity actually is. Suppliers often quote a week rather than a day, and a week means you plan for the last day of it.
4. Take off manufacture, exactly as the supplier states it, and write down in the same line what the supplier says that period runs FROM. That clause is the subject of the next section and it is worth more than the number in front of it.
5. Take off the approval loop, where there is one: the fabricator's drawing goes out, somebody responsible reviews it, comments come back, a revision is issued. Two rounds is normal and one round is optimistic.
6. Take off the survey or template slot, plus the turnaround between the surveyor leaving site and the order being releasable to the factory.
7. Take off the gap between your decision and a supplier who is able to act on it: the acknowledgement being issued, and any deposit clearing. Cleared funds on a Friday afternoon do not book a Friday slot.
8. What is left is the order-by date. Take your own float off that as well, put the earlier of the two on the wall, and treat everything after it as a decision that costs money rather than a decision that is still open.

"Eight weeks" from what, and ending where

Two clauses turn a lead time from a number into a date, and neither of them is usually on the quotation. The first is what the period runs from. Four answers are common and they are weeks apart on the same job: from receipt of a written order, from cleared funds, from approved drawings, or from a completed site survey. A supplier quoting eight weeks from approved drawings on an item that also needs surveying has quoted you the fourth interval on the list above and nothing else, and if you diary it as eight weeks from today you are already wrong by the survey slot, the turnaround, the drawing, the review and the revision.

The second clause is where the period ends. International commercial terms exist precisely to settle this and they are published: the International Chamber of Commerce's Incoterms 2020 rules define, among others, EXW where the goods are placed at the buyer's disposal at the seller's premises, FCA where the seller hands them to a carrier the buyer nominated, DAP where the seller delivers them to the named place ready for unloading, DPU where the seller unloads them, and DDP where the seller also clears them for import and pays the duty. For anything crossing a border those letters decide who books the lorry, who clears customs and who stands on the pavement at seven in the morning with a pallet truck. On a domestic job the same question hides behind plainer words — kerbside, tailgate, to the boundary, into the building — and the answer changes both the date and who pays when the load cannot get down the street.

The approval loop deserves treating as a scheduled activity rather than as a favour you will do quickly. AIA Document A201, General Conditions of the Contract for Construction, handles this properly: Section 3.10.2 requires a submittal schedule to be prepared and allow the architect reasonable time to review, and Section 3.12 governs shop drawings, product data and samples and is explicit that they are not contract documents and that their purpose is to demonstrate how the work will be executed. What that machinery is really doing is naming a duration and an owner for a period that otherwise floats. On a domestic job with no such contract, do the same thing by hand: agree a review period in days when the drawing is commissioned, and agree who signs. What signing a fabricator's drawing actually transfers is worked through on the truss-ordering page, and there is no reason to build that argument twice.

Get all of it onto the acknowledgement rather than the quotation. A quotation is a marketing document with a price on it; an acknowledgement is the supplier's own statement of what they have accepted, and it is the piece of paper that will be read if the delivery week slips. If the acknowledgement comes back without a delivery week, ask for one before the deposit goes, because that is the last moment you have any leverage at all.

The tape has to touch the building, and the man holding it has a diary too

Which items cannot be ordered until something exists to measure — glazing into formed openings, a staircase to a settled floor-to-floor, a worktop off levelled carcasses — is set out on the sequencing page and taken as given here. The scheduling consequence is the part worth adding: the survey is not an event, it is a booking with a lead time of its own, made with somebody who covers a region and fills a week at a time. Ask for the survey slot the day the opening is programmed, not the day it is formed, and ask separately how long the turnaround from survey to factory release runs, because those are two different periods and suppliers quote them as one.

Then there is the outcome nobody plans for: the survey comes back different from the drawing. An opening built to a drawing and an opening measured with a tape are related but not identical, and the gap decides who pays. Where the supplier surveys, the dimensional risk is generally theirs and a frame that does not fit is theirs to remake — which is exactly why suppliers insist on surveying and why a builder offering to save a week by supplying his own sizes is buying that risk without noticing. BS 8213-4, the code of practice for the survey and installation of windows and external doorsets, and ASTM E2112, the standard practice for installation of exterior windows, doors and skylights, both treat the survey and the tolerances around it as part of the installation rather than as paperwork before it. One line on the order — surveyed by the manufacturer — is worth more than any amount of care with a tape.

Delivered is not received

The lead time does not end when the lorry arrives. It ends when the right item is on site undamaged, and the gap between those two events has ended more programmes than any factory ever has. A cracked unit found in week nine is a fresh manufacturing interval starting from week nine; the same crack found while the driver is still there is a supplier's problem with a supplier's urgency behind it. Inspect on the pavement, before signing, and sign for the count and the condition separately from signing for the delivery.

The law behind that is worth knowing in outline because it sets deadlines you can miss by being polite. In the United States the Uniform Commercial Code gives the buyer a right to inspect goods before payment or acceptance under Article 2, section 2-513, a right to reject a non-conforming tender under section 2-601, and — the trap — a duty under section 2-607(3)(a) to notify the seller of a breach within a reasonable time after it is or should have been discovered, or lose the remedy. Section 2-612 deals with instalment contracts, which is what a window set delivered in two loads actually is. In the UK, the Consumer Rights Act 2015 sets a default delivery period of thirty days at section 28 and makes time of the essence only where that was agreed or where the consumer told the trader it was essential before the contract was made, which is a strong argument for the fix date appearing in the order rather than in a conversation. Between businesses the Sale of Goods Act 1979 leaves whether a time stipulation is of the essence to the terms of the contract, at section 10, which comes to the same practical instruction: put the date in writing.

Offloading is the other half of receiving and it is contracted, not assumed. Somebody is obliged to lift the load off the lorry and it is whoever the delivery term says it is; a driver who is only obliged to open the tailgate will do exactly that. A delivery turned away because the vehicle could not get down the street, or because nothing was on site to lift a glazed unit, is not a delivery that happens tomorrow — it is a redelivery, charged, at whatever slot the haulier has next. Check the access, the vehicle size the supplier despatches on, and the lifting arrangement at the point of ordering, when there is still time for the answer to change something.

Then it has to stand somewhere for however long it waits. Glazed units stand on edge on packers and not flat; frames stand vertical and supported; timber stays flat, off the ground and dry; and none of it stands where a scaffolder will be working. The Glass and Glazing Federation's good practice guidance and the National Glass Association's GANA Glazing Manual cover handling and site storage of glass, and every serious manufacturer publishes its own storage instructions with the warranty tied to them. An item delivered early to protect a programme and then stored badly has protected nothing, and it is a specific kind of miserable to lose a unit to a stack that fell over three weeks before anybody needed it.

Two dates, on the wall, where the client can see them

The whole of this comes down to two dates per item and a column of evidence behind each. The first is the last day the order can be placed. The second is the last day the order can be changed. Both belong on a single sheet with the supplier's name, the acknowledgement reference, the price validity date and the delivery week against them, and that sheet belongs somewhere the client walks past rather than in a folder on a laptop. Nothing focuses a decision about a colour like a date in a fortnight's time written in marker pen.

The characteristic failure this prevents is not dramatic. It is a job that is otherwise going well, with a competent crew and a reasonable client, standing still in week seven because a made-to-order item was ordered in week three on the assumption that eight weeks meant eight weeks from the day somebody remembered saying it. The subtraction takes an afternoon. Doing it in week one is the cheapest afternoon on the job.