SAVE BIG when you recycle your old Windows & Doors with us!

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Dundee's Top-Rated Double Glazing Specialists

Greencastle is Scotland’s leading home improvement company, providing quality services and installations that help homes become more energy efficient.

Our services include:

SAVE BIG when you recycle your old windows & doors with us.

Find out how much your old windows are worth when you enquire online today!

Get a quick and easy quote

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How many Windows & Doors would you like to Replace?
What Material are your existing Windows?
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Finance Options

Same Day Quotes

Quality Assured

Price Promise

Why Trust Greencastle?

At Greencastle, we understand that selecting new windows and doors can be daunting. With our extensive experience in the industry, we’ll ensure your new double glazing and home improvement products are installed with zero stress: from sales to installation and aftercare, you’ll get a first class job.

We’re committed to supplying high quality, A-rated double glazing to customers in Dundee and across Eastern Scotland. Combining innovative window styles with advanced manufacturing techniques, our double glazed windows provide energy efficiency, sustainability, durability and strength.

A Professional Experience

From quotation through to completion & service, you'll get a thoroughly professional job.

Leading warranty periods

Comprehensive product warranties across our entire range of home improvements.

Home visits & remote quoting

Free survey, free quote and independent advice at your convenience.

Multiple styles & materials

Whatever you're looking for, we make it happen with our extensive range!

Double glazed window installation in Dundee

Our Services at Greencastle

With a wide range of competitively priced, high quality home improvement services, we’ve got all your windows, doors and other needs covered.

Double glazing Installed in Dundee home

Double Glazed Windows

Double glazing Installed in Dundee home
Greencastle are expert home improvement specialists who want to help you transform your home. New double glazing, such as UPVC windows, is one of the best and most cost-effective improvements you can make.
Greencastle Scotland door installation


Greencastle Scotland door installation
We offer a wide variety of entrance doors, including UPVC doors for energy efficiency, composite doors for unique style, French doors for timeless elegance, bi-fold doors for those that want to be more connected with nature, and space-saving sliding patio doors.
Solar Panels Installed In scotland

Solar Panels

Solar Panels Installed In scotland
Protect yourself from rising energy bills with our expertly crafted solar panels. Gain a degree of independence from the national grid with your own solar panel system.

Loft Insulation

We insulate lofts with spray foam, preventing the energy you pay for from escaping your home, so you can experience higher levels of comfort and lower heating bills.

How it works

At Greencastle, we provide excellent service and make it easier than ever to transform your home in 4 quick and easy steps.
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Enter Your Details

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Talk To An Expert

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No obligation quote

Double glazed window installation

Get installed

Are you ready to transform your home? Fill out our 60 second contact form today!

What Are The Benefits of Double Glazing In Dundee?

We offer a first class job with all our windows, from window design to installation, so you can feel confident that you’re getting the best quality service with us.

Double glazed window installation in Dundee

Energy Efficiency

Double glazed window installation in Dundee

New double glazed windows and doors will improve your home’s comfort but also boost energy efficiency, leading to lower heating bills for years to come.

As home improvements go, replacing old windows with new double glazed UPVC windows is ideal because they do an excellent job at acting as a barrier between your home’s interior and those brisk outdoor temperatures. 

Reduced Condensation

Condensation on window

Condensation occurs when cold surfaces meet hot air. This is highly common on single pane windows, but is reduced by up to 85% on double glazing windows thanks to insulating gases between the panes keeping temperatures stable.

Condensation brings with it several issues, including dampness and structural damage, but also mould. Work with Greencastle to upgrade your home so you can reduce the risk of condensation issues.

Condensation on window
interior windows installed in kitchen

Increased Home Value

interior windows installed in kitchen
When you invest in double glazing, you’ll see significant improvements in the appearance of your home as well as a boost in your Energy Performance Certificate (EPC) rating, both of which will make your home more attractive to buyers. As a result, you’ll likely increase your home’s resale value, so some of the cost of your double glazing will effectively be recouped.
Reduced security with double glazed windows

Increased Security

Reduced security with double glazed windows

Double glazing is more secure than single pane windows. With two panes of glass instead of one, and solid construction in the frames that surround them, this makes your windows, new front door, or other glazing product even more secure.

All our products, including double glazing Dundee windows, come with multi-locking points and other modern security features to put your safety first and provide you with peace of mind.

SAVE BIG when you recycle your old windows & doors with us.

Find out how much your old windows are worth when you enquire online today!

Choose your colour

Choose a window & door frame colour that is perfect for your home.
Different coloured window frames offered by Greencastle

We Cover All Of Scotland

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We cover the whole of Scotland, not just Dundee, providing customers with quality home improvement services that will have a noticeable impact on their home comfort and energy bills. All are fitted to a high standard, so you can be assured you are in safe hands.

We provide free no obligation quotes for our customers and let you make your own mind up without any pushy sales team tactics. We’re able to help our clients in Scotland spread the cost of having windows, doors, and other products installed at their property with flexible finance options available.

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Double Glazing FAQs

Some of the most frequently asked questions about our double glazing in Dundee.

The main focus of our home improvements is helping homes improve their energy efficiency to lower energy bills overall. Improving energy efficiency with thermally efficient products, such as new windows and doors, means that less heat escapes from your home. 

Take a look below to see what we mean:  

  • Windows and Doors – Doors and windows can be heat sieves. As much as 25-30% of energy is lost through these areas. Our windows are double glazed and our doors are built with insulating material, meaning they stop nearly 100% of heat from leaving through these spaces. 


  • Roof – Your roof is also responsible for allowing heat to escape. Heat rises, and as such, you need insulation in your roof space to stop any energy from being wasted. Up to 25% of heat can be lost through these spaces without insulation. 


  • Solar Panels – Solar panels can generate energy on their own from the sun, converting daylight from the sun into usable energy for your home. This energy can be used immediately or stored in batteries for later use.

We offer great service and a wide range of energy efficient UPVC windows and doors in Dundee to suit your home:

Double Glazed –


We also offer double glazing in all of our doors –

  • composite doors
  • french doors
  • patio doors
  • new front doors
  • conservatories
  • and more…


We supply and install a full range of home improvement products, so contact us for further details. We provide independent advice so discuss your options with a member of our sales team today.

In some instances an existing window can be converted to double glazing, provided their current condition and design allow it. If your existing window frames are still robust and in good shape, you might be able to simply replace the single glazed panes with double glazed ones.

However, for windows that are significantly old or those not fitting standard sizes or shapes, retrofit double glazing might not be feasible or economical. In such instances, a complete window replacement would likely be the more viable solution.

Double glazed windows typically last for around 20 years or so. Many factors will ultimately influence this lifespan, such as the quality of the installation which is why you should rely on Greencastle experts to fit windows for you. A similar lifespan would be expected should you opt for triple glazing.

Choosing whether to repair or have new windows installed largely hinges on the nature of the problem you’re facing. Certain issues, such as failed seals or condensation between the panes, usually require replacement windows. This is because the integrity of the sealed unit has been compromised, affecting the insulating properties of the window.

Minor faults could be repaired, but for a long-term money-saving solution, having new windows installed is often the best option.

Check out our blogs on window repairs below: