Window and door delivery times: lead times and B2B logistics

Anyone who plans building sites knows this: a window or door that arrives a week late isn’t just “a week late”. It’s the installer standing idle, the bricklayer who needed to close up the openings, the end client calling, and sometimes a penalty. In window and door supply, lead time — the time between a confirmed order and the goods reaching site — matters as much as price, often more. Yet it’s the item people ask the fewest questions about when buying.

This article is for those who buy windows and doors to resell or install: window and door fitters, resellers, contractors managing several sites in parallel. The aim is practical — to understand what delivery times genuinely depend on, how to plan orders so you’re never caught short, and what to ask a supplier to get reliable dates rather than promises. I won’t cover how to write a technical specification or how to select a supplier here: those are separate topics, covered in two other articles I’ll reference further on.

One honest premise, which holds throughout the piece: no number of days quoted here is a guarantee. Lead times depend on the season, the current production load, component availability and order complexity. The figures cited are orders of magnitude given as examples, useful for reasoning about planning, not values to put in a contract in place of written confirmation from the supplier.

---

What’s really inside a lead time

When a supplier tells you “we deliver in three weeks”, that figure is the sum of several independent stages, each with its own risk. Understanding them matters because delays almost never arise where you’d expect.

The typical stages of a made-to-measure window and door supply, in order:

1. Order confirmation and technical validation. The supplier checks measurements, opening direction, colours, hardware, accessories. If a piece of data is missing or there’s an inconsistency, the clock doesn’t start until it’s resolved.
2. Component procurement. PVC profiles, glazing units, hardware, gaskets, accessories (handles, hinges, thresholds). Each component has its own supply chain and its own availability.
3. Production. Cutting, welding, machining, frame assembly, glazing, hardware fitting, quality control.
4. Packaging and stacking. Preparing the crates, protecting edges and surfaces, organising the load.
5. Transport and delivery. Route planning, carrier or dedicated vehicle timing, the unloading window on site.

The key point: these stages don’t always add up linearly. Production can only begin once the critical components are available. If the glazing unit with that specific make-up has a three-week procurement time, it doesn’t matter how fast the line is: the glass is the bottleneck.

---

What delivery times depend on: the variables that matter

Here’s an attempt to order the variables that, from experience in the trade, move dates the most. They don’t all carry equal weight, and almost none depend on the supplier alone.

Variable	Effect on lead time	Who controls it
Profile availability in stock	High: an out-of-stock colour/system extends things considerably	Supplier / extruder
Type of glazing unit	High: special, laminated, acoustic or safety glass has longer supply chains	Glazier
Hardware and accessories	Medium: standard configurations are ready, special solutions need ordering	Supplier / hardware supplier
Current production load	High: the queue lengthens in peak season	Supplier
Order complexity	Medium-high: special shapes, sliding systems, large spans, RC2	You (at design stage)
Completeness of order data	High: missing data blocks confirmation	You
Logistics and distance	Medium: delivery route, site accessibility	Supplier / carrier

Three items are worth dwelling on, because they’re where I see the most surprises.

Colour and system. A standard white in a widely used system is almost always the fastest configuration, because the profile is likely already in stock. A particular foil colour, a wood-effect finish, an out-of-range RAL, or a less common system may require procurement of the extrusion: here the difference between “ready” and “to be ordered” can be worth weeks. When the system is consistent and widely used — one of the practical advantages of working with Salamander profiles as a supply base — stock availability tends to be more predictable.

Glass. This is the most underrated variable. A standard low-emissivity double-glazed unit is one thing; a triple-glazed unit, a laminated acoustic glass, a safety glass or a particular composition follow different, often slower supply chains. If you have a mixed order with just one “special” window, that single piece can dictate the timing of the entire supply. Sometimes it’s worth splitting the order.

Seasonality. The sector has predictable peaks. High-demand periods — typically linked to favourable working windows and any incentives in progress — lengthen every supplier’s production queue at the same time. It’s not a single manufacturer’s problem: it’s the market. Those who order ahead during these periods notice it less; those who order at the last minute pay for the delay accumulated across the whole supply chain.

---

Planning orders so building sites don’t stall

The difference between those who manage delivery times well and those who chase delays isn’t down to the supplier’s speed. It’s down to the planning method. Here’s how I’d set it up.

Start from the installation date, not the order date. The reference point is when the windows and doors need to be on site, ready to fit — not when it’s convenient for you to place the order. From there, work backwards: the supplier’s indicative lead time plus a safety buffer equals the latest order date. Anything ordered after that date works against you.

Build a realistic safety buffer. A prudent margin between expected delivery and scheduled installation absorbs small slippages without stopping the site. Its size depends on the period and the type of order — larger in peak season and for complex orders, smaller for standard supplies in quiet periods. The buffer isn’t wasted time: it’s the insurance that the installer doesn’t stand idle.

Separate the critical from the routine. In a mixed order, isolate the long-lead-time pieces (special glass, particular colours, non-standard shapes) and consider ordering them earlier or separately, so they don’t hold up the rest.

Confirm the data before “ordering”. Many delays start here: an order placed but suspended because an opening direction, a dimension, or a colour confirmation is missing. For the supplier, the order isn’t “confirmed” until the data is complete — and the lead time starts from there, not from when you sent the email.

A table I use to reason things through, with purely indicative orders of magnitude (they depend on the period and production load):

Type of supply	Indicative lead time*	Planning notes
Standard PVC windows and doors, common colour, standard glass	Shorter	Configuration typically in stock
Order with particular colour/finish	Longer	Possible extrusion procurement needed
Order with special glass (triple, acoustic, safety)	Longer	Glass supply chain dictates timing
Sliding systems, large spans, special shapes	Longer	Greater production complexity
Peak season (any type)	Longer queue	Add extra buffer

*Figures should be read as orders of magnitude, not guarantees: always request written confirmation of the date from the supplier for your specific order.

For the structure of the order document — dimensions, tolerances, items to specify — the reference is the window and door supply specification: a well-written order is also an order that gets confirmed faster.

---

Recurring orders vs. spot orders

There’s a huge difference, in terms of the predictability of delivery times, between working continuously with a supplier and buying case by case, chasing the best price.

Spot orders. You buy when needed, wherever it costs less. Advantage: flexibility on price. Disadvantage on timing: each order is a fresh entry in the queue, with no historical priority, often with a supplier who doesn’t know your recurring needs. In peak season, you’re last in line.

Recurring orders. You work continuously with one or a few suppliers. Concrete advantages on timing: the supplier knows your typical configurations and can keep them more readily available; technical validation is faster because you speak the same language; in some cases scheduled production runs or periodic reorders can be agreed, reducing the wait. A continuous relationship doesn’t magically shorten production, but it reduces the friction that costs days.

For those reselling with regular volumes, thinking in terms of continuous supply — the typical model of a relationship with a window and door manufacturer or wholesaler — shifts logistics from “catching up” to “planning”. It’s not about discounts: it’s about predictability.

---

Delivery, transport and packaging: the last mile

The lead time doesn’t end when the window or door leaves the production line. The last mile carries its own weight and its own specific risks.

Packaging. A window or door damaged in transit is a delay in disguise: it has to be reported, replaced, remade. Proper packaging — edge protection, surface protection, glass protection — isn’t a cosmetic detail, it’s slippage prevention. It’s worth knowing how the supplier prepares the crates.

Transport. It makes a big difference whether delivery is by carrier on a pallet or by dedicated vehicle. The supplier’s delivery route may have fixed windows: knowing which days serve your area helps you fit the installation schedule around it.

Unloading on site. This is often the most overlooked variable. Site accessibility, someone present to receive delivery, any need for handling equipment: a delivery that can’t be unloaded gets sent back, and that’s the most frustrating delay because it has nothing to do with production.

What to agree in advance on the last mile:

• Mode of transport and type of vehicle planned.
• Delivery window and notice period (how far in advance the actual date is communicated).
• Who receives and checks the goods, and how any dispute is handled.
• Expected packaging condition and the procedure in case of transport damage.

---

What to ask your supplier for reliable delivery times

A serious supplier won’t promise you impossible timeframes: they’ll give you dates they can keep and will warn you if something changes. To understand who you’re dealing with, here are the questions I’d ask before committing a site to a date.

1. “When does the lead time start?” From the order email, or from confirmation with complete, validated data? This is the question that separates a realistic estimate from an empty promise.
2. “Which components of my order are in stock and which need procuring?” This tells you where the real bottleneck lies (usually glass or colour).
3. “Will you give me written confirmation of the date?” A verbal date can’t be planned around. A written confirmation can.
4. “How will you notify me if things slip?” The point isn’t whether an order can slip — it can. It’s how much notice you get to reorganise the site.
5. “What’s the current production load like?” An honest supplier will tell you if you’re in peak season and will suggest ordering ahead.
6. “How do you handle transport damage or a non-conforming piece?” Replacement speed matters as much as the speed of the initial supply.

Transparency on these six points is worth more than a lead time declared one day shorter. The production and organisational capacity behind the supply — a topic I explore further in production organisation — is what makes a date credible. For the broader criteria for evaluation, beyond delivery times, the reference is how to choose a reliable window and door supplier.

---

Logistics on large contracts

When moving from single-site supplies to large contracts, logistics change in nature: a delivery date isn’t enough — a staggered delivery plan aligned with the progress of works is needed. Delivering everything at once to a site that’s installing in batches means clutter, damage risk and improper storage.

In these cases, scheduled partial deliveries come into play, along with crate identification by batch or floor, and coordination with the works manager. It’s a world of its own, with its own planning logic, which I cover separately in the article on windows and doors for contract and large projects. The underlying principle, though, is the same as for a single site, just amplified: the date is built backwards from installation, with a buffer, and agreed in writing.

---

When it’s NOT worth pushing

Planning makes sense, but it shouldn’t become a fetish. Some situations where forcing the timeline is counterproductive:

• When you shrink the buffer to “save” a day. Ordering at the last minute to avoid tying up warehouse space is a false saving: the first hiccup stops the site, and the cost of that downtime far outweighs the benefit.
• When you demand fast delivery on complex orders. A triple acoustic glazed unit in a particular colour with a special shape can’t have the lead time of a standard white. Insisting shifts the problem onto quality or the actual date, not the declared timeframe.
• When you switch supplier purely for a shorter date. A promise of shorter delivery times from a supplier you don’t know, without written confirmation and without knowing what’s in stock, is worth less than a realistic date from a supplier you have a track record with.
• When you split an order purely for speed, ignoring the logistics costs. Separating out critical pieces makes sense; splitting everything into micro-deliveries multiplies transport runs, packaging and opportunities for error.
• When you chase urgency at the height of peak season. If the whole supply chain is backed up, no serious supplier will reliably let you jump the queue. Better to reschedule the installation than trust an optimistic date.

The practical rule: delivery times are managed upstream, through planning, not downstream, through pressure. Pressure on the last mile produces delays and disputes, not faster deliveries.

---

FAQ

How far ahead of installation should I order windows and doors? It depends on the type of order and the period. The correct logic is to start from the installation date, subtract the indicative lead time the supplier confirms for that order, and add a safety buffer — larger in peak season and for complex configurations. There’s no single figure that works for everyone: there’s a method.

Why does a supplier give me different timeframes for two similar orders? Almost always because of component availability and current production load. The same window or door can be “ready” if the profile and glass are in stock, or “to be procured” if that colour or that glazing unit needs ordering. Seasonal production load does the rest.

Does the lead time start when I send the order? Not necessarily, and it’s worth clarifying this straight away. For many suppliers, the count starts from confirmation with complete, validated data, not from the initial email. An order with missing data stays on hold and the days don’t count down: it’s one of the most frequent causes of perceived delay.

Is it worth using a further-away supplier if their production times are shorter? It needs to be assessed on the whole lead time, transport included, not just production. A shorter production time can be cancelled out by a less frequent delivery route to your area. What counts is the date on site, not the date it leaves the line.

How do I reduce the risk of being stuck on site? With three measures: a realistic safety buffer between delivery and installation, written confirmation of the date, and a supplier who gives you advance notice if something slips. Predictability matters more than raw speed.

Do recurring orders really have better delivery times than spot orders? Generally yes, but not because production is faster: because friction is reduced. The supplier knows your configurations, validation is quicker, and in some cases scheduled production runs can be agreed. It’s predictability more than speed.

---

In summary

The lead time of a window and door supply isn’t a number handed to you: it’s something you build together with the supplier, starting from the installation date and working backwards with a realistic buffer. The variables that matter — profile availability, type of glass, production load, seasonality, completeness of order data — are partly yours and partly the supplier’s, and nearly all manageable if you address them upstream.

Reliable logistics isn’t about more aggressive promises, but about transparency: knowing what’s in stock, when the clock starts, how you’re notified if something changes. If you want to understand how the production behind a credible date is organised, start from the page dedicated to LMT window and door production; if you’re thinking in terms of continuous supply for your business, the reference is the wholesale relationship. Delivery times are managed by planning, not by chasing.