External Venetian Blinds That Stop Heat At The Glass

Interior blinds manage heat that has already crossed the glass. External venetians intercept it before it arrives — on a north- or west-facing great room the difference in indoor comfort is dramatic, which is why architects reach for exterior shading on the hardest-hit elevations of a home first.

Built for exposed ground

Cornwall Hill sits on rolling, open terrain, and an external blind is genuinely exposed to weather in a way an interior one never is. Every system we fit is effectively always motorised, with a wind sensor that auto-retracts the blind before gusts build — the responsible spec, not an optional extra, for anything mounted outside on this kind of ground.

Estate-appropriate finishes

Exterior alterations on Cornwall Hill are usually visible from the road or a neighbouring stand, which means the aesthetics committee has a say. Powder-coated finishes come in a wide colour range, and we talk facade colour-matching through with you before anything is ordered so there are no surprises at sign-off.

• Wide aluminium slats (60–90mm class) in guided side rails or cables
• Motorised as standard, with wind-sensor auto-retract
• Powder-coated, weather-engineered finishes matched to your facade
• Best planned early on a new build; retrofit possible on suitable elevations

An honest note on cost

This is a premium spend, positioned as a genuine building improvement rather than window dressing — and a visible change to the facade, so it's worth the estate conversation early. For owners saying "the aircon can't keep up with that glass wall," it's usually the most effective single fix available.

What external venetians cost on the estate

Anything mounted outside the glass is a different class of product and the figures reflect it: R3,000 to R4,500 per square metre installed for a crank-operated external venetian, and R4,500 to R6,500 per square metre once it is motorised with sun and wind sensing. Guided side rails, heavier blade sections and the structural fixing work all sit towards the upper end.

The fixing substrate is checked on site before anything is quoted, because an external blind puts real load into whatever it is bolted to. Treat these as planning bands. Small windows carry a minimum charge, since the brackets, tube and fitting labour barely reduce with the opening. Each window on your schedule is costed on its own at the measure and confirmed in writing.