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Energy Efficient Windows

Improve the warmth, comfort and energy performance of your home with modern energy-efficient uPVC windows. By combining insulated frames, low-emissivity glass, gas-filled double or triple glazing and warm-edge technology, the right replacement windows can help reduce draughts, limit heat loss and create a more comfortable indoor environment throughout the year. The uPVC Company supplies made-to-measure energy-efficient windows, with professional installation available across Central Scotland and supply options throughout the UK.

Glazing Materials

Clear float glass has previously been the major material used for windows in houses. Advances in glazing technology mean that special glass is now available to control heat loss through the window.This low emissivity (low-e) glass has special surface coatings to reflect heat back through the window. The low-e coatings reflect between 40% to 70% of the heat that is normally transmitted through clear glass, while allowing the full amount of light to pass through.This type of glass is now standard under the Building Regulations for most homes in the UK.

Layers of Glass and Air

The traditional approach to improving the energy efficiency of a window has been to increase the number of layers of glass and air. Double- or triple-glazed windows have insulating air- or gas-filled spaces between each pane. Each layer of glass and the air spaces resists heat flow.The width of the air spaces between the panes is important, air spaces that are too wide have higher U-values and allow too much heat transfer. Highly energy efficient windows are manufactured with inert gases (argon or krypton) in the spaces between the panes because these gases transfer less heat than air.

Select energy efficient windows to improve comfort and
reduce Greenhouse Gases

Frame Materials

Window frames are available in a variety of materials and the frame material can be selected for price, maintenance or visual appearance. Any frame material can produce energy efficient windows if designed correctly. For consumers, it is important to get the most energy efficient window from the frame material that is chosen.

New Technology

New technologies are being used to develop and improve the energy efficiency of windows.Typical of these is the concept of ‘warm edge’ glazing to reduce heat losses at the edges of the glazing unit.

The following factors affect the whole Window U-value:

The type of glazing material.
The number of glazing layers.
The size of the cavity between the glazing layers.
The type of gas in the cavity between the glazing layers.
The design, material and type of frame and the other components.

Note: Always ensure that a quoted U-value is for the whole window and not simply for the glass.

Frequently Asked Questions
About Energy-Efficient Windows

What are energy-efficient windows?

Energy-efficient windows are designed to reduce heat loss through the glass, frame and seals. They typically combine double or triple glazing, low-emissivity glass, insulated uPVC frames, gas-filled cavities and warm-edge spacer bars.

How do energy-efficient windows keep a home warmer?

Energy-efficient windows slow the transfer of heat from inside the home to the outside. Low-emissivity glass reflects heat back into the room, while the sealed space between the panes provides additional insulation.

Will replacing my old windows reduce heat loss?

Yes. Replacing old, single-glazed, draughty or poorly fitted windows can significantly reduce heat loss. The level of improvement depends on the performance of the existing windows and the specification and installation of the replacements.

Can energy-efficient windows lower my heating bills?

Energy-efficient windows may reduce heating costs by helping the home retain more warmth. Actual savings depend on the property, number of windows replaced, insulation, heating system, energy usage and current energy prices.

Is double glazing energy efficient?

Yes. Modern double glazing provides good energy efficiency for many UK homes. It uses two panes of glass separated by an insulating cavity, helping reduce heat transfer and cold draughts compared with single glazing.

Is triple glazing better than double glazing?

Triple glazing can provide greater thermal and acoustic insulation, but it is not automatically the best option for every property. Modern double glazing may offer the right balance of performance, cost and natural light for many homes.

What is low-emissivity glass?

Low-emissivity, or low-E, glass has a thin transparent coating that reflects heat back into the home while allowing daylight to pass through. It is widely used in modern energy-efficient double and triple glazing.

What is the gas between double-glazed window panes?

The sealed cavity between the panes may contain an inert gas such as argon or krypton. These gases transfer less heat than ordinary air, improving the insulating performance of the glazing unit.

What is a window U-value?

A U-value measures how easily heat passes through a window. A lower U-value indicates better thermal insulation. Homeowners should compare the U-value of the whole window, including the glass and frame, rather than the glazing alone.

What is warm-edge glazing?

Warm-edge glazing uses an insulating spacer around the edge of the sealed glass unit. It reduces heat loss at the edges of the glazing and can help minimise cold spots and condensation around the window.

Will energy-efficient windows stop condensation?

Energy-efficient windows can reduce condensation caused by cold glass surfaces or failed glazing units. However, condensation inside the home can also result from excess moisture and inadequate ventilation, so new windows may not eliminate it completely.

Can energy-efficient windows reduce outside noise?

Yes. Well-fitted double or triple-glazed windows can reduce traffic and neighbourhood noise. The result depends on the glass thickness, cavity design, seals, frame and other sound paths within the property.

Which style of energy-efficient window is best for my home?

Casement, sash, tilt and turn, bow and bay windows can all be energy efficient when correctly specified. The best style depends on the property, preferred appearance, ventilation requirements, available space and budget.

How much do energy-efficient replacement windows cost?

The cost depends on the number and size of the windows, chosen style, glazing specification, frame finish and installation requirements. The uPVC Company provides free, made-to-measure quotations for homeowners across Central Scotland.

Why should I buy energy-efficient windows from the uPVC Company?

The uPVC Company supplies made-to-measure windows using energy-efficient glazing, insulated uPVC frames and modern sealing technology. It provides professional installation across Central Scotland and can supply replacement windows throughout the UK, supported by extensive manufacturing and installation experience.