Windows

PVC-U Casement Windows

The most widely fitted replacement window in the UK. Sensible money, strong performance, endless configurations.

Overview

What it is, in plain English

A casement window is hinged at the side or top and opens outwards. It is the default replacement window on most British homes, and for good reason: it seals well, it is straightforward to make in almost any shape, and it represents the most competitive part of the market.

Modern PVC-U is a long way from the chunky white frames of the 1990s. Sightlines are slimmer, the internal chambers are better engineered, and colour and woodgrain foils have become genuinely convincing.

Best for

Straight replacement
Best value
Low maintenance

Specification

The detail that changes the price

Materials: Multi-chambered PVC-U profile, usually 70mm or 80mm deep, either steel-reinforced or fully thermally reinforced. Profile depth and chamber count affect both thermal performance and how solid the window feels.
Energy efficiency: Most systems comfortably achieve a Window Energy Rating of A or A+, or a U-value at or below the 1.4 W/m²K required for replacement windows under Building Regulations. The glass unit usually does more work here than the frame.
Security: Look for multi-point locking, laminated glass on ground-floor and accessible openings, and a system tested to PAS 24. Secured by Design accreditation is the recognised police-backed standard.
Colours & finishes: White, cream, anthracite grey, agate grey, black, chartwell green and a wide range of woodgrain foils. Dual colour — a coloured exterior with a white interior — is common and usually costs less than colour on both faces.
Hardware: Handle style, hinge type and restrictors all change the feel and the cost. Egress or fire-escape hinges are needed on designated escape windows.
Glass: Double glazing with a warm-edge spacer and argon fill is standard. Triple glazing, acoustic laminate, obscure patterns and self-cleaning coatings are all options worth understanding before you specify.
Maintenance: Wipe the frames, keep the drainage slots clear and lubricate the hardware once a year. No painting.
Typical applications: Semi-detached and detached houses, terraces, bungalows and new-build replacements across the UK.

Honest assessment

Strengths and compromises

What it does well

The most competitive pricing in the market
Excellent thermal performance for the money
Huge choice of colours, glazing and configurations
Very little upkeep

Where it compromises

Frames are thicker than aluminium, so slightly less glass
Not always appropriate on listed or conservation-area properties

Next step

Get a considered quotation, not a sales visit.

Tell us about the property and a specialist reviews your requirement by hand.

Start my quotation Help me choose