Is It Worth Fitting Several VELUX Windows at Once?

Much of the effort in a roof window job is not the window itself. It is getting safe access to the roof, protecting the floors and furniture beneath, stripping the covering around each opening and making good afterwards. When several windows are done in one visit, that effort is set up once and used for all of them.

The roof covering is also lifted and relaid in one continuous run, and the flashing for each unit is built in at the same stage. That can give a more even finish than windows added at different times, where the tiles or slates around each new opening are matched to a roof that has weathered in between. Inside, the lining and finishing for each window can be completed in the same visit, with one clean-up rather than several. Dust sheets go down once, and rooms are handed back together, which matters when the windows light bedrooms and a landing that the household uses every day.

A job with more than one opening takes longer on the roof than a single window. A day or two suits a simple single rooflight, so a larger set is planned and agreed at the survey, with a realistic programme for the number of openings, the roof covering and the weather.

More windows are not always better. The aim is to put daylight where people stand, and that depends on the room. In a long loft bedroom, two windows spaced along the slope light both ends, where one large window leaves the far end dim. In a stairwell, a window above the top stair and another above the landing below light each flight. In a kitchen-diner with a sloping ceiling, a row of windows over the worktop gives even light for work, while one above the table suits the meal.

Spacing matters. Windows set too close together leave a shadow between them and use up roof structure without adding much light. Windows set too far apart leave bright and dark patches. The rafter spacing sets the grid, because each opening sits between rafters or involves trimming one. Matching the heights of the windows along the slope gives a tidy line from the street.

Sizes and a consistent look

Windows of one code look consistent from outside and are simpler to order together. If sizes puzzle you, the size code explainer helps. Mixing sizes is fine when the rooms below call for it, such as a small window for a bathroom and a larger one for a bedroom.

Every new opening changes the roof structure, so a set of new windows counts as building work, approved by the local authority or a registered building control approver. We notify where notification is needed, and the fitting follows the current regulations. Swapping existing windows like for like comes under Part L as controlled fittings, and each roof window must come in at the 1.4 W/m²K figure, or at band B on its energy rating.

Rooflights on a house are generally permitted development, and the conditions apply to the set as a whole. They are laid out in the planning guide. Flats, maisonettes, listed buildings and conservation areas are treated differently.

If one of the windows serves a bedroom in the roof, think about escape. A roof window serves as escape only up to 4.5 m above ground, and its opening must clear 0.33 m² without dropping under 450 mm in either direction. Over two storeys, the route out is a protected stair.

For a multi-window job, the survey looks at every room that is getting a window, as well as the roof as a whole. We discuss the spot in each room, mark the openings on the plan and check the rafters. One written quote covers the whole set, with a fixed figure, and a 10-year guarantee applies to the workmanship.

Where some windows are old ones coming out, the replacement guide describes each swap. The section hub is VELUX roof windows. Start with the survey form, or on WhatsApp at 07880 284133.