Premium side-hung casement windows with multi-point locking system and energy-efficient glazing for maximum security and ventilation

Get 20% Off your First Project

Premium Casement Windows

Our Casement windows represent the perfect blend of functionality and modern performance, offering unmatched ventilation and security for your home.

⭐⭐⭐⭐⭐Rated 4.9/5 for Casement Windows

10 Year Casement Guarantee

100% Ventilation

Casement Windows: Fresh Air, Security, & Modern Style

Introduction

Our Casement windows offer the perfect combination of functionality and style, providing unmatched ventilation and security for your home.

Each window is expertly engineered to open fully outward, maximizing airflow while creating a tight seal when closed for superior energy efficiency and weather protection.

Maximum Ventilation

100% opening for optimal airflow and natural cooling

Versatile Design

Available in multiple materials and configurations with various opening options

Enhanced Security

Multi-point locking systems and tight compression seal

Harrington Casement window showcasing superior ventilation and clean lines

Modern Functionality

Sleek design with superior performance

Ventilation

Maximum airflow

0.0 W/m²K

U-Value

Excellent thermal efficiency

0°

Opening Angle

Wide opening capacity

Year Guarantee

Comprehensive warranty

0.0

Star Rating

Average customer review

20% OFF

Your First Project

Limited time offer for new customers. Transform your home with our premium Casement windows.

*Terms and conditions apply. Offer valid until end of month.

Key Benefits

Why Choose Our Casement Windows

Our Casement windows provide superior ventilation and security with advanced locking systems, offering the perfect blend of functionality and energy efficiency.

Maximum Ventilation

Outward-opening design with 100% ventilation capability, perfect for capturing breezes and improving air circulation while providing unobstructed views when fully open

Superior Energy Efficiency

Tight seal when closed creates exceptional insulation with U-values as low as 1.2 W/m²K, minimizing drafts and reducing energy bills throughout the year

Enhanced Security Features

Multi-point locking systems around the entire perimeter create one of the most secure window designs available, with options for additional security features

Versatile Design Options

Available in multiple materials (uPVC, aluminum, timber), colors, and hardware options to match any architectural style from traditional to ultra-modern homes

Harrington casement windows showcasing superior air-tight sealing and energy efficiency

Superior Air-Tight Seal & Energy Efficiency

Our Casement windows feature exceptional thermal performance with compression seals and weathertight hinges. The full perimeter compression against the frame creates an air-tight barrier, providing outstanding energy efficiency while also offering excellent sound insulation.

U-values as low as 1.1 W/m²K
A++ energy rating standard
Multi-point locking for air-tight compression

Product Details

Crafted for Excellence

Modern Design & Functionality

Our Casement windows combine contemporary design with exceptional functionality to provide superior ventilation and clean sightlines.

Material Options

Choose from premium materials including uPVC, aluminum, timber, and composite. Each offers distinct advantages in durability, maintenance requirements, and thermal performance to suit your specific needs.

Smooth Operation

Side-hinged design with premium hardware allowing windows to open fully outward for maximum ventilation. Easy-to-use handles and mechanisms ensure smooth, effortless operation even after years of use.

Versatile Configurations

Available in single-sash, multi-sash, and combination configurations. Can be paired with fixed panels or installed as part of bay or bow window arrangements to maximize light and views.

Casement window design details showcasing clean lines and modern styling

Maximum Ventilation

With sleek modern design

Our Installation Process

Traditional craftsmanship with modern precision

Site Survey & Consultation

Our window specialists assess your property, discuss material options (uPVC, Aluminum, Composite), and take precise measurements to ensure accurate fit.

Bespoke Design & Engineering

We create detailed specifications for your casement windows, including material selection, finish options, and glazing configurations for optimal thermal performance.

Master Craftsmanship

Your windows are precision-engineered using advanced manufacturing techniques for superior strength, stability, and long-term performance.

Precision Installation

Our certified technicians ensure precise fitting with secure fixing, proper leveling, and thorough sealing to maximize energy efficiency and lifespan.

Maintenance Guidance

We provide comprehensive care guidelines including recommended treatment schedules, cleaning procedures, and checks for drafts and water ingress.

Casement windows professional consultation and precise measurement process - step 1 of 5

Free Consultation & Measure

We take precise measurements of your existing windows and discuss your preferences for style, colour, and functionality. Our experts will assess your property's specific requirements and explain the best options available.

Free Service

No cost, no pressure

Our Gallery

See our work in action

High-quality casement windows installation with side-hung design and multi-point locking security - project 1

High-quality casement windows installation with side-hung design and multi-point locking security - project 2

High-quality casement windows installation with side-hung design and multi-point locking security - project 3

High-quality casement windows installation with side-hung design and multi-point locking security - project 4

High-quality casement windows installation with side-hung design and multi-point locking security - project 5

High-quality casement windows installation with side-hung design and multi-point locking security - project 6

High-quality casement windows installation with side-hung design and multi-point locking security - project 7

High-quality casement windows installation with side-hung design and multi-point locking security - project 8

Our Guarantee

Your peace of mind is our priority

10-Year Guarantee

Our premium casement windows come with a 10-year guarantee, ensuring exceptional long-term durability and performance.

Weatherseal Protection

Our casement windows are designed with weatherseals that prevent air leakage and maintain a tight seal, ensuring energy efficiency and comfort throughout the year.

Insurance-Backed Guarantee

Complete peace of mind with insurance-backed guarantees covering all workmanship, materials, and weather-sealing for our casement windows.

Maintenance Support

Ongoing support including maintenance advice and care services to ensure your casement windows last a lifetime.

Our Promise to You

We stand behind the quality of our products and workmanship. If you're not completely satisfied, we'll make it right. It's that simple.

Customer Testimonials

Hear from our satisfied clients

★★★★★

The casement windows are exceptional. The superior ventilation and unobstructed views they bring to our property are exactly what we wanted, and their energy efficiency has noticeably reduced our heating bills. Unlike other window types, these open fully for maximum airflow.

James R

Hampstead

★★★★★

What impressed me most about Harrington's casement windows is the perfect balance of functionality and design. They've transformed our home while providing the security and energy efficiency we needed.

Sarah M

Surrey

★★★★★

From the detailed consultation about material options to the final installation, Harrington Windows were excellent. The quality of craftsmanship and attention to period details in our conservation area property exceeded our expectations.

David & Emma P

Kent

★★★★★

4.9 out of 5

★★★★★

9.87 out of 10

Standard uPVC Windows

Standard value improvement

Premium Options

Good for contemporary homes

Feature	Our Casement Windows	uPVC Windows	Aluminum Windows
Aesthetic Appeal	Natural beauty with distinctive grain and character	Limited wood-effect finishes	Modern, sleek appearance
Thermal Performance	Excellent natural insulation with air pockets (U-values from 1.1 W/m²K)	Good insulation with multi-chambers	Poor without thermal breaks
Environmental Impact	Renewable resource with negative GWP, 100% recyclable	High carbon footprint, difficult to recycle	Energy-intensive production, 100% recyclable
Lifespan	50-100+ years with maintenance, repairable	25-35 years typically, not repairable	30-40 years typically
Maintenance Requirements	Microporous finishes need recoating every 7-10 years	Minimal maintenance, can discolor over time	Virtually no maintenance needed
Touch & Feel	Warm to touch, less condensation	Cool to touch	Cold to touch, prone to condensation
Suitability for Conservation	Ideal for heritage buildings and conservation areas	Often rejected in conservation areas	Rarely suitable for period properties
Value Added to Property	Significant value enhancement, attractive to buyers	Standard value improvement	Good for contemporary homes