How to choose replacement window installers

Once you’ve made the decision to upgrade your windows, the next step is to find the right installer.

There are several things you can look out for to ensure you make the best decision for your budget and individual priorities. In most circumstances, you’ll be better of choosing an installer with strong accreditations, proven experience, clear guarantees and genuine customer reviews.

It’s also beneficial if they have a comprehensive product range, with various window styles and materials to choose from. This makes it easy to find the right fit for your home, regardless of whether you reside in a rural Essex cottage, an East London new build, etc. It’s also highly recommended that you choose an installation company who offer clear no-obligation quotes beforehand, so you aren’t met with any unpleasant surprises afterwards.

At Advanced Glazing Systems, we’re proud to be an independent, family-run company with over 20 years of experience when it comes to installing home improvement products in the South East. From your initial consultation through to aftercare, we focus on delivering a smooth, stress-free experience with high-quality results every time.

Reliable replacement windows installers: Key things to watch out for

Before choosing an installer, it helps to know what to look for. A reliable company should demonstrate trust, transparency and technical knowledge from the very beginning.

Accreditations

Accreditations are a strong sign that a company meets recognised industry standards. They give homeowners peace of mind that the installer follows proper practices, uses quality products and meets legal requirements.

Look out for:

• FENSA: Ensures window installations comply with UK building regulations
• Glass and Glazing Federation: Confirms high standards in products and workmanship
• Secured by Design: A police-backed initiative focusing on home security
• BFRC ratings: Confirms the energy performance of windows
• TrustMark: Demonstrates quality and consumer protection

Advanced Glazing Systems’ accreditations

We are proud to hold a wide range of trusted accreditations:

• FENSA registered: Our installations meet all current building regulations
• Glass and Glazing Federation: Ensures our products and installations meet the highest standards
• Secured by Design: Our windows and doors are designed to improve home security
• BFRC accredited: Our products are independently rated for energy performance, helping improve your home’s energy efficiency
• TrustMark approved: A government-backed quality mark recognising good trading practices

These accreditations give homeowners real confidence when choosing us as their window installers.

Strong reviews

Customer reviews offer honest insight into the quality of workmanship and service you can expect. Always check reviews on independent platforms such as Google and Trustpilot.

A good window replacement company will have consistent, positive feedback covering:

• Professionalism
• Installation quality
• Customer service
• Communication
• Aftercare support

Advanced Glazing Systems’ reviews

We are proud to hold a 4.9-star average from Which? Trusted Trader, alongside excellent ratings on TrustATrader, where we have 4.87 stars from 849 reviews.

One customer said:

“We recently had a new front door and internal aluminium doors installed and we couldn’t be happier with the result. The quality is excellent, the finish is flawless and they’ve completely transformed the look of our home.”

Another customer, Ana, said:

“I couldn’t be happier with my new front door… the service was professional, friendly and reliable.”

We’re proud of these reviews, and appreciate all of our customers taking to time to give their feedback!

Experience

Whilst there are many good startups up and down the country, most feel more secure in choosing a company with a proven track record, with installers who have been there and done that.

Advanced Glazing Systems’ experience

We were established in 2004, and are run by ourselves, the Barnett family! We are proudly independent, and truly believe that our knowledge of the area and it’s properties sets us aside from national corporations. With over 20 years of experience, we have built a strong reputation across Essex and London.

Our team understands the full process, from survey and manufacture to installation and aftercare. We only employ installers who take pride in their work and follow proven methods, ensuring every window installation is completed to a high standard.

Guarantees

A reliable installer should offer strong guarantees that protect your investment. This typically includes:

• Product guarantees
• Installation guarantees
• Insurance-backed warranties

These provide peace of mind that if anything goes wrong, you are covered.

Advanced Glazing Systems’ guarantees

We offer a comprehensive 10-year warranty on our products and installations.

In addition, our warranty is backed by an insurance-backed guarantee from GGFi, ensuring your investment is protected even in the unlikely event of company changes.

This gives homeowners complete peace of mind when choosing us for their window replacement project.

Free, no-obligation quotes

A trustworthy professional installer will likely offer a free consultation and no-obligation quote. This allows you to explore your options, understand pricing and make an informed decision without pressure.

At Advanced Glazing Systems, we provide:

• A free home visit
• A tailored quotation
• Honest advice on your home improvement project

Our product range

When choosing replacement windows installers, it is important to select a company that offers a wide range of high-quality products.

Look for:

• Energy-efficient glazing
• Choice of frame materials such as uPVC and aluminium
• Multiple styles and finishes
• Modern security features

High-quality windows can significantly improve your home’s energy efficiency, which means they help keep heat inside your home and reduce energy loss.

At Advanced Glazing Systems, we only supply high-performance products from trusted systems, ensuring long-lasting results.

Replacement windows from Advanced Glazing Systems

We offer a wide range of new windows designed to suit every style of home, from modern builds to period properties.

Window styles

Here is a closer look at our main window styles:

• Casement windows
  The UK’s most popular window style, these are renowned for simplicity. They open inwards or outwards from a hinge.
• Flush casement windows
  Having enjoyed a rapid rise in popularity in the past ten years, flush casement windows have an unmistakeable appearance. The glass sits completely level with the window frame, without sacrificing on performance.
• Sliding sash windows
  Designed to open vertically, these windows are ideal for period homes. They’re great for ventilation, and their traditional look has been in-demand for centuries.
• Bay and bow windows
  These project outward from the wall of the property, creating extra space and allowing more light into the room.
• Tilt and turn windows
  These open inwards, either tilting at the top for ventilation or fully opening for easy cleaning.
• Heritage windows
  Designed to replicate traditional styles, these windows are ideal for conservation areas and period properties.

Window materials

We offer a choice of high-quality materials:

• uPVC
  Low maintenance and highly durable. uPVC is one of the most popular materials for replacement windows in the UK due to its strength and affordability.
• Aluminium
  Slim, strong and modern. Aluminium frames allow for larger panes of glass and are available in a wide range of colours.

How we work

Our process is designed to be simple and stress-free:

1. Quotation
   We visit your home to take measurements, discuss your needs and provide a clear, no-obligation quote.
2. Production
   Your windows are precision-manufactured to your exact requirements.
3. Installation
   Our experienced installers carry out a clean and professional fitting.
4. Aftercare and support
   We provide full documentation, warranty details and ongoing support.

Frequently asked questions

What is the average lifespan of new windows?

Modern double glazed windows can last upwards of 20 to 30 years with proper care. High-quality installation and regular maintenance can extend their lifespan even further.

Do new windows improve energy efficiency?

Yes. New windows with double or triple glazing reduce heat loss, helping to improve your home’s energy efficiency. This means your home stays warmer and you may see lower energy bills over time.

Do you offer patio doors as well as windows?

Yes, we install a full range of patio doors including French, sliding and bifold options, to complement your new windows.

Who are Advanced Glazing Systems?

We are a family-run company established in 2004 by John Barnett and his family. Based in Essex, we provide professional window installation services across Essex and London. The confidence we have in our work is backed by a comprehensive 10-Year guarantee.

We specialise in:

• Replacement windows
• Doors
• Conservatories
• Glazing solutions

We are accredited by:

• FENSA
• Glass and Glazing Federation
• Secured by Design
• BFRC
• TrustMark

Call us on +44 (1277) 230101
Email: sales@advancedglazingsystems.co.uk

To summarise

• Choosing the right replacement windows installers is key to long-term performance and peace of mind
• Always check accreditations, reviews, experience and guarantees
• High-quality products improve your home’s energy efficiency and security
• Advanced Glazing Systems offers a wide range of windows, including uPVC and aluminium options
• Our expert team delivers professional installation with full aftercare and support