Which roof window brand is best?
The one that has a flashing kit for the covering on your roof, a frame size that fits between your rafters, and a spare pane still available in fifteen years. That sounds like a dodge and it is not. All four of the manufacturers commonly fitted in Essex build to the same product standard and all four make a competent window. The differences that matter on a specific house are about fit, kits and availability rather than about quality.
Sunspire installs VELUX, Fakro, Keylite and Roto units. What follows is what actually separates them, in the order the decisions come up on a real job. The product detail behind the most commonly specified of them sits on VELUX window installation.
The question that decides it before brand does
Start with the roof, not the badge. Three facts rule most of the shortlist out before anyone has expressed a preference: the covering and its profile depth, the rafter or truss centres, and the pitch.
A deep profile concrete interlocking tile at 100mm depth needs a kit rated to that depth, and not every manufacturer offers one across every size. A trussed roof at 600 centres caps the width at around 550mm, and the maker whose grid has a 550 width in the height you want is the one you can use. A shallow slope at sixteen degrees needs a unit rated to it. Work through those three and the field is often down to two before anyone opens a brochure.
VELUX, and what catalogue depth buys
The Danish manufacturer is the reason people say VELUX when they mean any roof window, and the practical advantage of that market position is depth. The flashing catalogue covers more coverings, more profile depths, more recessed variants and more combination arrangements than anyone else’s. Blinds, accessories and spares are stocked by builders’ merchants across the county rather than ordered in.
That matters most in two situations. On an awkward covering, where the kit either exists or the job becomes a hand-detailed exercise. And in twenty years, when a sealed unit or a set of gaskets is wanted for a window nobody has thought about since it went in. It is not the cheapest name on a quotation and it very rarely is the wrong answer.
Fakro, and the pivot that sits higher
The Polish manufacturer’s signature is the raised pivot. On a standard centre pivot the sash rotates about a bar roughly two thirds of the way up, which puts the top of the glass swinging into the room at head height. Fakro moves that pivot point higher up the sash.
Two things follow. You can stand at the open window without ducking under the sash, which in a loft with limited headroom is a real gain. And the effective view out improves, because more of the glass is above the pivot line. The range also reaches into some larger sizes than the equivalent grid elsewhere, which is useful on a generous cut roof where the timber allows it. The pivot mechanism is the reason to choose it, rather than price.
Keylite, and what comes in the box
The Irish manufacturer took a different route and built the thermal detail into the product. A Keylite window arrives with an expanding thermal collar already fitted around the frame, so the insulation jacket that is a separate ordered item elsewhere is part of the unit.
The benefit is not really thermal, since a properly fitted separate collar performs the same. The benefit is that it cannot be left out. On a job where the quotation is thin and the installer is quick, the collars are exactly what disappears, and a window that carries its own removes that possibility entirely. For anyone comparing quotations without a technical background, that is a genuine argument.
Roto, and the frame designed to turn
The German manufacturer’s distinguishing feature is the pivot bearing itself, which on the main range can be set at different heights within the frame rather than fixed at one position. The window is specified to suit the height it is being installed at, so a unit low on a slope and a unit high on the same slope behave differently in the hand.
Roto also states sizes in decimetres rather than a letter code, so a 7/9 is 740 by 980 millimetres. It is a smaller presence in the merchant chain here than the other three, which cuts both ways: the product is well made and the local spares position is thinner. On a house where an existing Roto is being matched, it is the obvious choice. On a fresh installation it wants a reason.
Whether a kit exists for the covering you have
This is the single most decisive line in the whole comparison and it is almost never in a sales conversation.
| Covering | What to check before choosing a brand |
|---|---|
| Plain clay tile | Flat covering kit, and whether a tile-and-a-half is needed at the opening |
| Concrete interlocking tile | Profile depth measured, and a kit rated at or above it |
| Natural slate | Low profile kit, and whether a recessed version is offered |
| Essex peg tile | Kit availability at all, and hand dressing at the head |
| Pantile | Deep profile kit with a dressed skirt into the rolls |
Every manufacturer covers the first three well. The last two thin out quickly, and on the hand made tile roofs around Thaxted, Coggeshall and Saffron Walden the availability of a proper kit is what chooses the window. Kits never interchange between makers, so this is decided at the same moment the brand is.
Spares in fifteen years, and the plate on the sash
A roof window is a twenty five year purchase and the sealed unit is the part that ages out first. When it does, what you want is a replacement pane available against a code, not a bespoke item measured by a glazier at height.
Every one of the four stamps a data plate on the top edge of the sash carrying the type, size and glazing codes. What varies is how long the parts behind those codes stay obtainable and how quickly they arrive. Deeper distribution in the UK means a gasket set or a handle next week rather than next month. It is an unglamorous criterion and it is the one people are grateful for a decade later.
Matching what is already in the roof
On a house with two or three roof windows already fitted, staying with the same maker is usually right even if another brand looks better on paper. The frame proportions differ, the external cladding colours differ slightly, and two makes side by side on one elevation are visible from the garden in a way that is difficult to unsee.
It also keeps the blinds, the flashing kits and the spares on one system. Where an old unit is being changed and the others are staying, read the plate on the sash of a neighbouring window first. Skylight replacement covers how a like for like unit goes into an existing trimmed opening.
Comparing two quotations that name different brands
Put them side by side and check five lines. The frame size in millimetres, not the code, since codes differ between makers. The glazing specification with a whole window U-value and the plane it was measured in. The flashing kit reference and the covering it is rated for. Whether the underlay collar, insulation collar and vapour barrier collar are named. And who is forming the opening and making good the plaster.
When those five match, the remaining difference is the real price difference. When they do not, the cheaper quotation is usually cheaper for a reason that is written down somewhere in what is missing. Fuller cost detail sits on the costs page, and the towns covered are listed under areas.
Tell us about your roof
We start with the building, the covering and the slope. Then we tell you what will suit it, and what it will cost, as a fixed written number.
- Surveyed before it is priced
- 10-year workmanship guarantee
- Building Control notification handled
- New installations and replacements