Loft windows are wonderful things. They pull light down into a room that would otherwise be shaded by its own roof, and they give you a view over rooftops that no ground-floor room can match. The catch is that the same height and angle that make them so lovely also make them hard to dress. A rooflight tilted back in the slope, a dormer window sitting low in the eaves, and a gable window facing straight at a neighbouring house all present different problems. In nearly every case, the answer is not to shut the light out but to filter or redirect it.

Start with what the window actually needs to do

Before you order anything, spend a few minutes thinking about the room and the view. A bedroom used for sleeping wants a proper blackout option for summer mornings, when the sun rises before six and a rooflight acts like a spotlight. A home office or dressing area mainly needs to stop passers-by, or the neighbours opposite, seeing in during the day. A bathroom or en-suite needs both privacy and moisture tolerance. Orientation matters too: south-facing rooflights gain heat as well as light, so a reflective or thermal lining earns its keep, whilst north-facing ones can afford to be left barer.

Ask yourself three questions:

• Who can see in, and from where? A window facing open countryside needs far less than one looking onto a pavement or a close neighbour's landing.
• When do you need privacy? All day, or only after dark when interior lights make the glass transparent?
• How do you use the room? Sleep, work and bathing all pull you towards different fabrics and mechanisms.

Blinds: the practical choice for rooflights and slopes

For windows set into the pitch of the roof, blinds are usually the only sensible option. Curtains cannot hang on a sloping surface without looking awkward, and they would block the very light the window was put there to deliver. Pleated and roller blinds made specifically for roof windows clip or screw into the window's own frame, so they travel with the sash when it opens. Look for side guides or tensioned cords — an unsupported blind on a tilted window will flap and rattle in a draught.

In dormer windows and vertical gable windows, a Roman blind is often the best-looking answer. Mounted on a batten fixed to the ceiling just in front of the window head, it falls in soft folds and can be pulled up to a neat stack during the day, leaving the glass clear. Choose a light-filtering lining for a living space and a blackout lining with a thermal backing for a bedroom. Roller blinds suit a crisper, more contemporary loft and take up almost no room, which matters if the window sits close to a low wall or a bed.

Shutters for dormers and low eaves

Fitted shutters have become the default choice in loft conversions for good reason. They sit inside the window reveal rather than over it, so they do not add bulk to a headroom-poor space, and they let you control light in bands. Tier-on-tier shutters, where the top and bottom halves open independently, are ideal for a dormer: leave the top louvres tilted open for daylight and keep the lower half closed against the street. Café-style shutters, covering only the bottom half of the window, work well where a window drops down to floor level in the eaves.

Shutters need a square, solid reveal to fix into. Older lofts sometimes have uneven plasterboard or a sloping return, so measure at the top, middle and bottom of the opening before ordering. Waterproof finishes are available for bathrooms, and hardwood or a good quality composite will cope with the temperature swings that lofts experience far better than a cheap softwood.

Curtains and sheers that keep the room bright

Curtains still have a place, particularly on gable-end and dormer windows where there is a vertical surface to hang them from. The trick in a loft is to keep the stack as tight as possible. A ceiling-fixed track running wall to wall, rather than a pole with chunky finials, lets the curtains pull right back into the corners and leaves the maximum glass on show.

For privacy without gloom, sheer voile or a fine linen-look fabric is hard to beat. A single sheer panel across a large loft window softens the view in and out, blurs the shape of anyone moving about, and still lets most of the daylight through. In bedrooms, layer a sheer with a heavier pair on the same track: sheer by day, blackout by night. Pencil pleat or a shallow wave heading works better than deep pinch pleats in a room with limited headroom.

Layering, measuring and the finishing details

Most successful loft window schemes use two elements rather than one — a blind or shutter for control, and a sheer or curtain for softness. A few practical points will save you a second visit from the fitter:

• Measure the reveal, not the glass. Note any handles, vents or opening mechanisms that the blind must clear.
• Check the swing of the window. A roof window that rotates fully needs a blind fitted to its frame, not to the surrounding plaster.
• Mind the headroom. Anything projecting more than about 100mm into the room will feel intrusive under a low slope.
• Think about cords. Child-safe, cordless and wand-operated options are sensible where a window sits low or near a bed.
• Keep colours light. Soft greys, off-whites and warm neutrals reflect light back into the room; dark fabrics absorb it and make a loft feel smaller.

Get this part right and the loft stops feeling like a converted roof space and starts feeling like the brightest, calmest room in the house.