Box Sash Window Replacement in Gillingham, Dorset | Three New uPVC Casement Windows Installed

Looking for box sash window replacement in Gillingham or anywhere in Dorset? At Goldhillglazing, we recently completed the replacement of three ageing timber box sash windows with modern, energy-efficient uPVC casement windows, transforming the appearance, warmth and comfort of this home.

This project is a great example of how replacing old single-glazed sash windows can dramatically improve insulation, reduce maintenance and give a property a fresh new look without altering its character.

Whether you’re searching for replacement windows in Gillingham, double glazing installers in Dorset, or a trusted local window company, this case study shows the quality of workmanship you can expect from Goldhillglazing.

Project Overview

Location: Gillingham, Dorset

Product Installed:

Three white uPVC casement windows
Energy-efficient double glazed sealed units
Low-E coated glass
Argon gas filled units
Warm edge spacer bars
High-security multipoint locking system
Low-maintenance white uPVC frames

Why the Homeowner Decided to Replace Their Box Sash Windows

The original timber box sash windows had served the property for many years but were becoming increasingly inefficient.

Like many older sash windows throughout Dorset, they suffered from:

Heat escaping through single glazing
Cold draughts during winter
Increased outside noise
Higher heating costs
Regular painting and timber maintenance
Less security than modern window systems
Stiff operation due to age

The homeowner wanted a practical, long-term solution that would improve the home’s energy efficiency while providing reliable, secure windows that require very little maintenance.

After discussing the available options during our survey, they chose modern uPVC casement windows as the best balance between appearance, performance and value.

Survey and Measuring

Every installation begins with a detailed survey.

At Goldhill Glazing we never rely on estimates or assumptions. Every opening is carefully measured to ensure the replacement windows fit perfectly.

During the survey we checked:

Opening sizes
Existing structural condition
Internal plaster reveals
External brickwork
Cill condition
Frame depth
Drainage requirements
Ventilation requirements
Building Regulation compliance

This attention to detail ensures every window is manufactured specifically for the property.

Removing the Existing Box Sash Windows

Removing old box sash windows requires care and experience.

The original timber frames were carefully dismantled without causing unnecessary damage to the surrounding plasterwork or brickwork.

Once removed we thoroughly cleaned the openings before preparing them for installation.

This stage is particularly important because a clean, square opening allows the new windows to perform exactly as designed.

Installing the New uPVC Casement Windows

The new windows were positioned using precision packers before being checked for:

Level
Plumb
Square
Diagonal measurements
Smooth operation

Once everything was perfectly aligned the frames were mechanically fixed into position before being insulated and sealed using high-quality perimeter sealants.

Every window was adjusted before completion to ensure effortless opening and closing.

Why We Installed Energy-Efficient Double Glazing

The new sealed units include modern energy-saving technology including:

Low-E Glass

A microscopic low-emissivity coating reflects heat back into the home while still allowing natural daylight to pass through.

Argon Gas

Argon provides better insulation than ordinary air, helping reduce heat loss through the glass.

Warm Edge Spacer Bars

Warm edge technology reduces heat transfer around the perimeter of the glass and helps lower the likelihood of condensation.

Together these features create a much warmer, more comfortable home throughout the year.

Security Improvements

Modern windows should do much more than simply keep the weather out.

The new windows include:

Multipoint locking
Internal glazing beads
Reinforced uPVC profiles
Key-locking handles
Tough, durable hardware

These features offer significantly improved security compared with older timber sash windows.

The Difference After Installation

The transformation was immediate.

From inside the property the rooms now feel:

Brighter
Warmer
Quieter
Easier to ventilate

From outside, the clean white uPVC frames complement the brickwork while giving the property a refreshed appearance.

The homeowner also benefits from virtually maintenance-free windows that no longer require regular sanding, filling or repainting.

Benefits of Replacing Old Box Sash Windows

Many homeowners across Gillingham, Shaftesbury and the wider Dorset area are choosing to replace ageing timber sash windows because modern double glazing offers:

Lower heating bills
Better insulation
Improved security
Reduced condensation
Less outside noise
Increased property value
Easier cleaning
Virtually maintenance-free frames
Long-lasting performance
Improved comfort throughout the home

Why Choose Goldhillglazing?

Goldhillglazing is a family-run glazing company based near Shaftesbury, serving homeowners throughout Dorset, Wiltshire and Somerset.

When you choose us you’ll deal directly with experienced professionals from the first survey through to the completed installation.

We pride ourselves on:

Quality over quantity
Accurate surveying
Professional installations
Honest advice
Attention to detail
Excellent customer service
FENSA registered installations
High-quality products backed by manufacturer guarantees

We believe every installation should look as though it has always been part of the home.

Areas We Cover

Although this project was completed in Gillingham, we regularly install replacement windows throughout:

Shaftesbury
Gillingham
Mere
Motcombe
Bourton
Marnhull
Sturminster Newton
Sherborne
Blandford Forum
Salisbury
Tisbury
East Knoyle
Donhead St Mary
Warminster
Wincanton
Yeovil
And across Dorset, Wiltshire and Somerset.

Frequently Asked Questions

Is it worth replacing old box sash windows?

In many homes, yes. Modern double glazing offers significantly improved insulation, security and ease of maintenance while helping reduce energy bills.

Will new uPVC windows make my house warmer?

Yes. Energy-efficient double glazing with Low-E glass, argon gas and warm edge spacer bars reduces heat loss compared with older single glazing.

How long does window replacement take?

Most residential window replacement projects are completed within one day, depending on the number of windows being installed.

Are your replacement windows FENSA registered?

Yes. Goldhillglazing installs replacement windows in accordance with current Building Regulations, and qualifying installations are FENSA registered.

Thinking About Replacing Your Windows?

If your existing windows are cold, draughty or expensive to maintain, we’d be happy to help.

Goldhillglazing supplies and installs high-quality replacement windows across Gillingham, Shaftesbury and the surrounding areas. From a single misted unit to a full-house window replacement, we provide honest advice, expert surveying and professional installation.

Book your free, no-obligation quotation today and discover how modern energy-efficient windows can transform your home.