Double Glazed Units
Replacement Double Glazed Units Made to Measure
Order made-to-measure double glazed units online from EasyFit Window. Our sealed glass units are available in custom widths and heights, with a choice of 4mm or 6mm glass and basic, A-rated or C-rated specifications.
Whether you are replacing a misted or damaged sealed unit or buying glass for a new window or door, you can select the size, unit thickness and finishing options you require before receiving an instant online price.
Choose your double glazed unit below to start customising your order.
Need help choosing? Call our team on 01625 783100 or email sales@easyfitwindow.com before placing your order.
- Made to your measurements
- 4mm or 6mm glass
- Within 14 working days
Buy replacement double glazed units online
A double glazed unit—also called a sealed unit or insulating glass unit—is the glass component fitted inside a window or door frame. It normally consists of two panes of glass separated by a spacer bar and a sealed cavity.
If the existing frame remains in good condition, you may be able to replace the sealed glass unit without replacing the complete window. This can be a more focused and less disruptive solution when the existing glass has become misted, cracked or damaged.
EasyFit supplies double glazed glass units made to the dimensions and specification entered when ordering. Select the appropriate product above, enter your measurements and choose the available options to receive your price.
Choose the right double glazed unit
Different rated units offer different levels of thermal performance.
Basic Units
Standard float glass and a standard spacer bar. Suitable where enhanced energy performance is not the main requirement. Available in 4mm or 6mm glass.
A-Rated Units
Argon gas, high-efficiency glass and a thermal spacer bar for improved thermal performance in compatible A-rated window systems.
C-Rated Units
An argon-filled alternative for C-rated window systems. Check the product composition carefully — 4mm and 6mm builds differ.
4mm or 6mm glass
EasyFit offers units manufactured with 4mm and 6mm glass.
The 4mm product pages state that the glass must be upgraded to 6mm where both dimensions exceed 1,300mm or where the largest dimension exceeds 2,400mm. Always follow the limits and instructions displayed in the relevant product configurator.
If you are uncertain which thickness is required for your measurements or application, contact EasyFit before ordering.
When should a sealed unit be replaced?
Condensation or misting trapped between the two panes is one of the clearest signs that a sealed unit has failed. Moisture inside the cavity generally means the edge seal is no longer keeping the unit sealed.
Condensation on the room-facing or outside surface does not necessarily indicate sealed-unit failure. The important distinction is whether the moisture is trapped between the panes and cannot be wiped away.
Other reasons to consider a replacement include:
- Misting between panes
- Failed seal
- Cracked glass
- Damaged unit
Customising your sealed glass units
Depending on the product selected, the online configurator allows you to choose from options including:
- Overall double glazed unit build-up
- Clear or patterned glass
- Toughened glass
- Georgian or cottage bars
- Diamond or rectangular leading
- Spacer-bar colour
- Special manufacturing instructions
Available options differ between products. Select the base unit that meets your performance requirements before choosing its decorative and finishing details.
If the specification you need is not listed, call 01625 783100 or email sales@easyfitwindow.com. EasyFit may be able to help with additional sizes, glass options or styles.
Toughened and patterned glass options
Toughened glass is available as an option across EasyFit’s online double glazed unit configurators. Safety-glazing requirements depend on where the glass will be installed, its dimensions and the nature of the opening.
Do not select standard glass solely on price if the unit is being installed in a door, beside a door, close to floor level or in another safety-critical location. Ask a competent installer or EasyFit for advice if you are uncertain about the appropriate specification.
A range of obscure patterned glass is also available for locations where privacy is important, such as bathrooms, entrance areas and overlooked windows. Pattern availability should be confirmed within the selected product.
Measuring your replacement unit
Made-to-measure glass must be ordered accurately. Do not assume that the visible area of glass represents the full width and height of the sealed unit, because part of the glass is normally retained within the frame.
Where possible, obtain the dimensions and overall thickness from the existing unit after it has been safely removed. You will normally need to confirm:
- The sealed unit’s width in millimetres
- Its height in millimetres
- Its overall thickness or build-up
- The thickness of each pane
- Whether safety glass is required
- Any patterned, decorative or spacer-bar requirements
For example, a build-up shown as 4-16-4 consists of a 4mm pane, a 16mm cavity and a second 4mm pane, producing an overall unit thickness of 24mm.
Measurements and specifications are the customer’s responsibility because each unit is manufactured to order. If you are unsure, contact EasyFit or ask an experienced glazier to measure the existing unit before purchasing.
What affects the price?
The cost depends on dimensions and specification. Enter your size online for an accurate made-to-measure price.
- Size
- Glass thickness
- Unit build-up
- Toughened glass
- Patterned glass
- Decorative details
How to order online
- 1
Choose your unit
Select a 4mm or 6mm basic, A-rated or C-rated product.
- 2
Enter dimensions
Add width and height in millimetres and choose the unit build-up.
- 3
Select options
Choose pattern, toughened glass, bars, leading and spacer colour.
- 4
Check and order
Review the full specification before adding the unit to your basket.
Double glazed unit FAQs
What is a double glazed unit?
A double glazed unit is the sealed glass component fitted inside a window or door frame. It usually consists of two panes of glass separated by a spacer bar and an enclosed cavity. It is also commonly called a sealed unit, double glazed sealed unit or insulating glass unit.
Are double glazed units the same as complete windows?
No. A double glazed unit is the glass assembly only. A complete window also includes the surrounding frame, glazing beads, seals, hardware and opening mechanism where applicable.
Can I replace a misted double glazed unit without replacing the frame?
Often, yes. If moisture is trapped between the panes but the existing frame remains structurally sound, the failed sealed unit can frequently be replaced independently. Have the frame assessed if it is damaged, distorted or leaking.
Why is there condensation between the panes?
Condensation trapped between the panes generally indicates that the sealed edge of the unit has failed and moisture has entered the cavity. The practical remedy is normally to replace the sealed unit rather than attempt to remove the moisture.
Should I choose a basic, A-rated or C-rated unit?
Choose a specification compatible with the window system and the performance required. Basic units are intended for applications where enhanced thermal performance is not essential. EasyFit’s A-rated and C-rated options use energy-efficient glass and argon-filled cavities, with exact compositions shown on their respective product pages.
Should I choose 4mm or 6mm glass?
The appropriate glass thickness depends on the unit’s dimensions, location and application. EasyFit states that its 4mm units must be upgraded to 6mm where both dimensions exceed 1,300mm or the largest dimension exceeds 2,400mm. Contact EasyFit if you are uncertain.
What does 4-16-4 mean?
A 4-16-4 double glazed unit contains one 4mm pane of glass, a 16mm cavity and a second 4mm pane. Its total nominal thickness is therefore 24mm.
Can I order patterned or toughened glass?
Yes. EasyFit’s configurators provide a selection of patterned-glass designs and a toughened-glass option. Availability and pricing are displayed after you select the relevant product.
How long do double glazed units take to manufacture?
EasyFit currently estimates within 14 working days for glazing. Units with leading, Georgian bars or bespoke requirements may take several days longer. Delivery timing can also vary by destination and is provided as an estimate.
Are the units made to measure?
Yes. Each unit is manufactured according to the dimensions and options entered in the product configurator. Check the width, height, overall thickness and complete specification carefully before submitting the order.
Need help choosing your double glazed unit?
Call 01625 783100
