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Double Glazed Windows Perth

GreenCastle offers reliable double-glazing services in Perth to improve the appearance, energy efficiency, and security of your home. Receive a free no-obligation quote for our custom double-glazed windows and doors.


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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!

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Why Choose GreenCastle Double-Glazed Windows?

Double glazed window

We are a Scottish window company with over 50 years of experience serving customers in Perth and surrounding areas. Our name is well-established as a highly recommended double-glazing windows company known for the quality of our installations and competitive pricing.

Our double-glazing products are made to exceptionally high standards, offering you durable and visually appealing new glazing for your home. We offer bespoke double-glazing options to perfectly suit your home.

Double glazed window

Energy Efficient New Double-Glazing

Perth homeowners with older, or single-glazed windows, may experience greater heat loss and higher energy bills. GreenCastle double-glazing provides low U-values and enhances the thermal efficiency of your home, resulting in potential savings on heating costs.

Double-glazing, which consists of two panes of glass (or three in the case of triple-glazed windows), along with an insulating barrier of gas between the glazing, increases heat retention in the home. This enhanced energy efficiency can help reduce heating bills by reducing the need for heating to be switched on for lengthy periods.

Noise Reduction

Double glazing in modern Dundee home

Installing double-glazed windows or doors can have a significant impact on reducing external noise entering your Perth home, making it especially beneficial for those affected by noise from neighbours or traffic.

Double-glazing is effective in reducing noise, with an average reduction of around 65% due to its ability to absorb sound vibrations and prevent sound from passing through the frames.

Double glazing in modern Dundee home

How it works

At Greencastle Home Improvements, we have made it easier than over to transform your home in 4 quick and easy steps.


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Boost Home Security

Bay window green

Double-glazing and its accompanying locking systems enhance home security by making it more difficult to break into without causing noticeable noise, unlike standard single-glazing.

Our windows have steel-reinforced uPVC frames as standard, which makes forced entry very difficult. Additionally, we provide Yale multi-point locking systems with both our windows and doors to further enhance security.

Secondary glazing installed in Scotland home

Increase Your Home’s Value

Secondary glazing installed in Scotland home

Installing double-glazed windows and doors can be a wise investment in your home, particularly if you choose to sell in the future. Adding new double-glazed external doors, like French doors, patio doors or bifold doors, can greatly enhance the overall appearance of your home.

Installing double-glazing products instead of single glazing can increase the resale value of a property by approximately 10%.

sash windows installed in bedroom

UV Protection

sash windows installed in bedroom

Exposure to the sun’s UV rays while indoors can affect your family’s wellbeing as well as your home furnishings and fabrics by prematurely ageing them.

Double-glazed windows with built-in UV screening are effective in blocking up to 99% of ultraviolet rays from entering homes in Perth, making them a highly beneficial home improvement.

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Reduced Condensation

Reducing noise with double glazing

Condensation is a common issue in homes that have single glazing or failing double-glazed units. The growth of mould and presence of damp patches can have negative effects on health and can lead to respiratory illnesses. Additionally, over time, condensation can cause structural damage to your home.

Installing new double-glazing can significantly reduce condensation, often by as much as 85%.

Reducing noise with double glazing

Easy To Maintain

Open double glazed window

Maintaining your GreenCastle windows and doors is easy. Unlike traditional timber window frames, uPVC or composite frames do not need regular maintenance like repainting and varnishing. Simply wipe down the frames with water and a mild detergent.

Open double glazed window


UV protective double glazing in dundee home

GreenCastle windows are manufactured in the UK, taking into consideration the specific weather conditions in Scotland. These windows require minimal upkeep and can endure for 20 years or more, withstanding even the harshest weather in Perth.

UV protective double glazing in dundee home

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!

Double-Glazing Window Styles

Our double-glazed windows offer a variety of customisable styles for both windows and doors, ensuring the highest quality.

  • Casement windows are a classic style and are considered one of the more affordable types of windows.
  • Flush windows have a sleek and elegant design that appeals to traditional aesthetics.
  • Cottage windows have a rustic charm that complements both modern and older properties.
  • Sash windows provide an elegant charm with their traditional timber design.
  • Bay windows are used to create an architectural focal point.
  • Shaped windows are unique window designs that add a distinctive touch to homes.
  • The windows are reversible, making them easy to clean and providing good ventilation.
  • Tilt-and-turn windows provide enhanced child safety.

Window Frame Colour Options

GreenCastle offers a variety of uPVC window and door frame colours, ranging from contemporary and bold to more sophisticated shades and wood grain effects. This allows homeowners to personalise their homes and make a style statement.

In addition to the standard white, there are a variety of colour options available for your interior window frames, including cream, green, blue, red, black, grey, and brown. If you prefer a different colour on the interior frames compared to the exterior, we can accommodate that.

Window Hardware

GreenCastle double glazed windows and doors are supplied with high-quality hardware that complements the double-glazing, enhancing both security and energy efficiency. All locks, handles, and hinges undergo rigorous testing to meet technical standards, ensuring optimal functionality and seamless operation.

Benefits of GreenCastle Double-Glazing

interior windows installed in kitchen

Our range of double-glazing services offers multiple benefits for Perth homeowners. 

  • Multiple window customisation options.
  • Precision, made-to-measure installation.
  • We offer a 10-year guarantee on frames and glazing for added assurance.
  • The window locking systems come with a lifetime guarantee.
interior windows installed in kitchen
double casement window with top light

Value-Added Services

double casement window with top light

Our double-glazing installation service includes a variety of additional features.

  • We offer a consultation and quote without any obligations or fees.
  • Free window style-and-design service.
  • We offer financing options, including 12 months of zero-interest credit.
  • We help you save money by recycling your old windows with us.


Please contact us to schedule a double-glazing consultation and receive a free quote.

Double-Glazing Perth - FAQs

Most frequent questions and answers

Double-glazed windows or doors usually do not require planning permission, unless they are being installed in a listed building or conservation area, in which case listed-building consent or planning permission is usually needed.

If you are considering double-glazing as a home improvement investment, we can provide guidance on potential planning permission concerns for your property in Perth.

The lifespan of double-glazing is determined by factors such as the quality of the installation and materials used, as well as the level of maintenance for the windows.

Our products are made with high quality materials and have a lifespan of at least 20 years. UPVC windows and doors, for instance, may have a longer lifespan if they are installed in a sheltered location that is not exposed to extreme weather. Some double-glazing may even last up to 50 years.

Regular cleaning and maintenance can help to prolong the lifespan of your double-glazed units. It is recommended to clean the glass, frames, and sills using a soft cloth or sponge and a mild detergent, as this will effectively remove dirt without causing any damage to the surfaces.

Using a high-pressure hose to clean window exteriors can potentially damage the seals and lead to leakage.

Window maintenance involves regularly inspecting locks and seals, and promptly addressing any needed repairs.

Whether a double-glazed window needs to be replaced or repaired depends on the cause of the problem. If the sealed unit has been compromised, a full window replacement is usually necessary.

If the problem is less severe, such as minor cracks in the frame or damaged hardware, these issues can often be fixed.

The cost of double-glazing can differ based on factors such as the dimensions of the window or door, the quality of materials used, the level of customization, and the need for any structural changes. Generally, composite doors and windows for new installations tend to be more costly compared to UPVC windows and doors.

GreenCastle Home Improvements offers free quotes for double-glazing in Perth, with no obligation.

casement box bay window installed in scotland

Casement Windows

Single or double-panelled windows, these are hinged from the side, top or bottom. Available in uPVC, timber or aluminium, and in a range of different colours, they can be customised with options including decorative glass, clip-on Georgian bars, and different finishes. Our casement windows offer the latest high performance technology when it comes to security. Highly energy efficient, our casement windows are A+ rated for maximum thermal efficiency.

Available in a range of colours.

sash windows installed in bedroom

Sash Windows

Providing effortless use with smooth sliding mechanisms, sliding sash windows have the appearance of timber but the functionality of UPVC.  Available  in a range of styles, including Georgian, Victorian and Edwardian, our sash windows are long-lasting and relatively maintenance-free.

Available in a range of colours.

shaped windows installed to brighten scotland home

Shaped Windows

Non-standard shaped windows provide unique design appeal to a property. These types of windows, including arch and circle shapes, can boost light coming into a property.

Available in a range of colours.

tilt turn windows installed in open room

Tilt & Turn Windows

Tilt & turn windows are highly versatile and easy to use. A perfect option for homes with young children, their tilt and turn functionality means you can conveniently ventilate your home without any risk to safety.

Available in a range of colours.

Bay window installed in scotland home

Bay Windows

Forming a bay on the edge of a room, these type of windows give your room a spacious feel. Their design allows lots of natural light  into your space and are an attractive addition to a home when viewed from the outside.

Available in a range of colours.

flush casemet window installed in scotland home

Flush Windows

A blend of classic style with modern hardware, flush windows are the perfect option for both heritage and modern properties. Their thermal efficiency and noise reduce capabilities make them a great addition, and they can be custom-made for your home.

Available in a range of colours.

scotland cottage installed with scottish style windows

Cottage Windows

Our cottage windows help retain authentic old-style charm for period properties or can even  add a vintage touch to new build properties. With a traditional design, they often feature multiple small panes and cross-bars.

Available in a range of colours.

Coloured window installed in office scotland building

Coloured Windows

Choose windows frames in colours that perfectly match your own aesthetic requirements. Ensure they match your home and stand out for the right reasons.

Available in a range of colours.

Secondary glazing installed in Scotland home

Secondary Glazing

As an alternative to standard double glazing, secondary glazing is slim additional window inside the existing one and improves thermal insulation and noise reduction.

Available in a range of colours.