UPVC vs Aluminium Windows in Nepal: Which Is Right for Your House?
A straight comparison of UPVC and aluminium windows for Kathmandu Valley homes — dust sealing, noise, heat, maintenance, lifespan and cost.
This comes up at almost every site visit where windows are being replaced. Both materials are fine; they are good at different things. Here is the comparison without the sales pitch.
Dust and sealing
This is the deciding factor for most Kathmandu households. UPVC frames are made with multi-chamber profiles and continuous rubber gaskets that compress when the sash closes, which seals better than most aluminium systems at the same price point. If your main complaint is wiping dust off the sill every morning, UPVC is the stronger answer.
Heat and cold
Aluminium conducts heat readily. In an unbroken aluminium frame, heat moves straight through the metal — warm in and cold out. UPVC does not conduct in the same way, so rooms hold temperature better. Thermally broken aluminium closes much of this gap but costs considerably more than the standard sections sold in most Kathmandu shops.
Strength and span
Aluminium is stronger per unit of section, so it can carry large glass with slimmer frames. For a shopfront, a big sliding door or a wide balcony opening, aluminium often looks better and may be the only practical choice. UPVC handles large openings too, but needs steel reinforcement inside the profile and the frames end up visually chunkier.
Maintenance and lifespan
Neither needs painting. Aluminium can pit and its powder coating can chalk over years of sun, and cheaper anodised finishes discolour. UPVC does not rust and does not need painting, but poor-quality profile without UV stabilisers can yellow. Both should be given twenty years or more if the product is decent — with either material, the hardware usually needs attention before the frame does.
So which should you choose?
For a home on a dusty or noisy street where comfort matters, UPVC is usually the better buy. For very large openings, shopfronts and commercial frontage where slim sightlines and span matter, aluminium usually wins. Plenty of houses end up with both — UPVC in bedrooms and aluminium on a large living-room slider. There is no rule saying you must pick one for the whole house.
Frequently asked questions
Is UPVC or aluminium cheaper in Nepal?
For a standard residential window they are broadly comparable, and the difference between two UPVC quotes is often larger than the difference between UPVC and aluminium. Profile quality, steel reinforcement and hardware brand move the price far more than the base material does.
Does UPVC really reduce traffic noise?
Noticeably, compared with an old ill-fitting frame, because most noise leaks through gaps rather than through the glass. For a serious reduction on a busy road you need double glazing — single glazed UPVC will reduce the noise but not remove it.