Venetian blinds for a street with three window ages on it

Timber, for the original joinery

Higgovale still has narrow-sash Victorian terraces standing next to architect-renovated homes with frameless glass — sometimes on the same block. Wide timber slats on woven ladder tapes suit the original sash windows and the Cape Dutch gables that give the suburb its character, and we template the headrail to the reveal depth of the joinery rather than forcing a standard aluminium bracket onto a window it was never designed for. Timber does the same work down the slope on the Victorian and Edwardian sashes of Oranjezicht, where fitting inside the reveal keeps the blind a furnishing decision rather than a heritage one.

Aluminium, for the rooms timber can't do

Bathrooms, kitchens and laundries are where fabric and timber both eventually fail — slim, sealed-finish aluminium slats are the moisture-proof answer, in 25mm for a crisp look or 50mm for fewer lines. Powder-coated aluminium also handles the City Bowl's proximity to Table Bay better than an untreated finish, though the exposure up here is lighter than the open Atlantic Seaboard. In Tamboerskloof's sectional-title flats, aluminium usually wins on those same practical grounds, since a later block has no original joinery for a timber slat to answer to.

The real argument: light by the hour, not by the switch

A roller is open or closed by degrees; a venetian steers light direction — tilt up for glare-free daylight, tilt down for privacy from a neighbour's upper storey, close flat for dark. On a steep slope like Higgovale's, where one house can shade another by mid-morning and lose that shade again by three, that hour-by-hour control is often the more useful spec than a single fixed sunscreen.

Aluminium or timber: what the slats cost

Everything below is per square metre of blind, installed. Aluminium slats in 25mm or 50mm run around R1,000 to R1,500 per square metre. Timber is the step up at R1,600 to R2,600, partly for the material and partly because the extra weight demands a stronger headrail and better ladder tape if the blind is to keep hanging true in a deep old reveal.

Motorise the tilt and aluminium becomes R2,500 to R3,600 the square metre, timber R3,000 to R4,500 — the gap is simply weight the motor has to move. A narrow bathroom or landing window carries a minimum charge whichever material you choose. None of this is a quote — the exact figure per opening is written up after the free measure, once the reveal has been checked and the slat held against your own joinery.