Replacing windows in stages without ending up with a mismatch

Why staged window projects go wrong

There are good reasons to replace windows in stages. You might want the coldest bedrooms done before winter and the rest after the next tax return. You might be renovating the kitchen next year and want its windows done with the renovation. You might simply prefer to try one or two rooms before committing to the whole house.

The problem is time. Two years after the first stage, the details that made the first windows what they are have faded from memory. Which colour was it exactly? Which handle? Was the glass in the bedroom the same as the living room? The original quote might say double glazed aluminium in a dark colour, which is not enough to order a match. The supplier may have changed ranges, or you may be dealing with a different business altogether.

The result is often a house where the front bedroom windows have slightly wider frames than the living room, the handles are a different shape, and the dark grey is not quite the same dark grey. Some differences are visual, while a different frame, glass or operating system can also alter performance. Record both appearance and specification rather than assuming a close colour match means the same window. Planning the first stage gives you a record against which later substitutions can be assessed.

Plan the whole house before stage one

The most useful step is to make decisions for the whole house at the start, even though you will only pay for part of it now. Walk through every opening and give it an ID, as described in the guide to comparing quotes line by line. Then mark which openings are in stage one and which come later.

Next, choose the product family for the whole house: the frame range, the colour, the hardware style and the general glass approach. Ask the supplier to quote stage one in detail and to give at least an indicative description of the later openings in the same range. That way the choices you make for stage one are made with the whole house in mind.

Opening styles need the same thought. If the living room will eventually have awning windows, and the bedrooms you are doing now look onto the same side of the house, consider whether the bedrooms should match that style. The opening styles guide helps you decide room by room, while this step makes sure those room choices sit well together across an elevation.

Finally, ask how retrofit and replacement will be mixed. If some openings will keep their frames and take new sealed units while others get new frames, the two will look different. That can be fine on separate elevations but awkward side by side on one wall.

What has to match between stages

Most mismatches come from a short list of details. Each one is easy to record at the time and hard to reconstruct later.

• Frame range. Different ranges have different frame depths and face widths. The visible width of frame and sash, often called the sightline, is what the eye notices first when two windows sit side by side.
• Colour and finish. The colour name alone is not enough. Record the manufacturer's colour code and the finish, such as matt, satin or gloss, or anodised.
• Glass appearance. Coated and toned glass can look slightly different in colour and reflection. Obscure glass patterns vary widely. Record the glass make-up for each opening.
• Hardware. Handle shape, finish and lock type. If you want one key for every window, this needs to be planned from the first stage.
• Screens. Mesh colour and screen frame colour are easy to overlook and quite visible from outside.
• Internal trims. Architrave profile and reveal finish, if the installer is replacing them.

Performance can differ between stages without anyone noticing. If you want the whole house to behave consistently, ask for the glass make-up and frame range to stay the same, or at least be documented. The guide to window energy ratings explains how to check the rated performance of each configuration.

Colour and finish: the hardest thing to match later

Frame colours are usually powder coat or anodised finishes on aluminium, or coloured and foiled finishes on uPVC, and timber is painted or stained. Each of these can change with exposure to sun and weather. A frame that has faced afternoon sun for several years may look a little different from a brand new frame in the same colour, even if the product and code are identical.

You cannot prevent that entirely, but you can manage it. Keep the colour code and finish from stage one. When ordering later stages, ask the supplier to show you a sample in the same code held against your existing frames in daylight. If the difference bothers you, arrange the stages so that each elevation is completed in one go, so any small difference falls around a corner rather than across a wall.

Judge samples beside the installed frame in the lighting that matters to you. Colour, gloss, texture, viewing angle and the condition of the older finish can each affect the comparison. A screen image or colour name alone cannot settle whether you will notice the difference.

Choosing which windows to do first

There is no single right order, but some approaches cause fewer problems. Grouping by elevation means the street side, or the garden side, is done all at once and looks consistent. Grouping by room means each room is finished at once, which suits people who want one room completely comfortable before moving on.

Comfort priority is the other common driver. People often start with bedrooms that are cold in winter, rooms that face a noisy road, or west facing rooms that overheat. The guide to signs your windows need replacing can help identify which openings are in the worst condition.

Access is a practical factor. Upstairs windows that need scaffolding or special access are usually better grouped into one stage, so the access cost is incurred once. Doors and large sliding units may also need extra hands and are worth grouping.

Other renovation work can affect the order, alongside safety, weather damage and access needs. If a kitchen or bathroom will be rebuilt, its windows are usually best done with that work, because the wall linings around them will be disturbed anyway.

The records to keep after every stage

The single most useful habit is a project file, paper or digital, with one section per stage. After each installation, ask the supplier for an as-installed list that shows each opening ID with its frame range, colour code, glass make-up and hardware. Some suppliers provide this as a matter of course. If yours does not, the order confirmation usually has most of it.

Add photos of every finished opening, inside and out, and close-ups of any labels or markings on the frames or glass. Keep the warranty documents with supply and installation dates, and confirm the start event stated in each document. The ACCC explains that warranties are additional to consumer guarantees. Note anything that changed from the quote, such as a handle that was substituted or a size that was adjusted on site.

Update the list of remaining openings at the same time. If you change your mind about a future opening, note it then, while the reasons are fresh. When you come back for the next stage, hand the whole file to whoever is quoting. It saves time on their side and gives them what they need to match the earlier work.

When the product or supplier changes between stages

Over a few years, product ranges are updated, colours are discontinued and businesses change. If the exact product from stage one is no longer available, ask for the closest current range and compare it physically: frame face width, colour sample, handle and screen. A photo is not enough for this.

If a different business will do the later stage, give them your project file and ask them to confirm in writing which details they can match and which they cannot. Ask how their products would affect any warranty on the earlier stage, for example if they adjust adjoining trims or seals.

Where the difference is noticeable, it is often better to change a whole elevation to the new product than to put two products side by side. That might mean moving one opening between stages to keep a wall consistent.

Trims, paint and keys between stages

Matching is not only about the windows. When a window is replaced, the architraves and reveal linings around it are often removed, replaced or repainted. If stage one gets new architraves in a particular profile, write the profile down, or keep an offcut. Standard timber profiles change over time too, and a room where two windows have different architraves looks unfinished.

Paint is similar. Record the paint colour and sheen used on reveals and trims at each stage, and whether the installer or a painter did the work. If a room is half done in one stage and half in the next, plan to repaint the whole room at the end rather than trying to touch up.

Keys and locks are easy to forget. If you want every window lock to work with one key, the lock type needs to be chosen and recorded at stage one, and ordered to match at every later stage. Mixing lock systems means carrying several keys, or leaving some windows unlocked because the key is never where you need it.

Hypothetical example: a house done in three stages

A family plans to double glaze a single storey house over three years. Stage one covers the two front bedrooms and the lounge, the whole street elevation. Stage two will be the rear living area with the sliding door, planned for the kitchen renovation. Stage three will be the laundry, bathroom and side bedroom.

At stage one they choose the frame range, colour, hardware and keying for the whole house and get indicative descriptions for the later openings. After installation they file the as-installed list, the colour code and finish, photos and warranty papers. Two years later the kitchen builder's window supplier uses that file to order the rear windows, and the family checks a colour sample against the front windows before the order goes in.