Upgrading windows and doors is a significant investment, but it can substantially improve a property’s energy efficiency. Replacing old single-glazed timber or metal-framed windows with modern uPVC double or triple-glazed units or swapping single-glazed timber sash windows for double-glazed timber sash windows with draught-proofing can enhance the property’s energy performance considerably.
Key Considerations
Before making any changes, check with your local authority for specific regulations regarding window replacements, particularly in conservation areas or on protected buildings. While some restrictions may apply, modern timber double-glazed sash windows are often permitted in conservation areas if they replicate the appearance of the original windows.
How Double Glazing Works
The thickness of the glass plays a crucial role in insulation.
- Single glazing is typically 3–4mm thick.
- Double glazing consists of two glass panes, usually 4mm each, with a gap of up to 20mm in between.
This gap is filled with an inert gas, such as argon, which reduces heat transfer. The sealed design creates an effective thermal barrier, preventing heat from escaping your home.
Secondary Glazing: A Cost-Effective Alternative
For a more budget-friendly option, secondary glazing can be added to single-glazed windows. This involves installing a second pane on the room-facing side of the existing window, usually affixed to the original timber frame. While secondary glazing is less efficient than uPVC double glazing due to the absence of inert gas, it still improves insulation at a much lower cost.
The Importance of Draught Proofing
Draught proofing windows is another vital step in improving energy efficiency:
- uPVC windows come with built-in draught proofing.
- Timber-framed windows often lack this feature but can be retrofitted with draught-proofing measures, such as seals or brushes, to prevent heat loss.
By addressing draughts and upgrading windows thoughtfully, you can make your property more energy efficient, comfortable, and cost effective to heat.
