Warmer, quieter rooms start with the right windows

Windows are one of the largest sources of heat loss in older homes. Upgrading them reduces draughts, cuts heat loss, and noticeably improves comfort, but the right approach depends on your home, your windows, and whether you are in a conservation area.

Why windows matter

Single-glazed windows lose roughly twice as much heat as double-glazed ones. Even older double glazing with failed seals or blown units can be a significant source of heat loss and draughts.

Beyond energy performance, window upgrades improve comfort in ways that are immediately noticeable. Rooms feel warmer because the glass surface is closer to room temperature, reducing the cold radiating effect you feel near old windows. Street noise drops. Condensation on the glass reduces or stops entirely.

Window upgrade options

There are several approaches, and the right one depends on the condition of your current windows, whether they are in a listed building or conservation area, and your budget.

Type

Secondary glazing

Double glazing replacement

Triple glazing

How it works

A second pane fitted inside the existing window frame

Existing windows replaced with new double-glazed units

Existing windows replaced with three-pane units

Thermal performance

Good - significant improvement over single glazing

Very good: the standard for most homes

Excellent: best thermal performance

Appearance

Additional pane visible internally

New frames and glass - wide range of styles

Same as double glazing but slightly thicker units

Conservation area constraints

Often the only permitted option for listed buildings

May require matching original style and materials

Less commonly approved in conservation settings

Cost

Lower

Moderate

Higher

Noise reduction

Excellent - often better than double glazing for noise

Good

Very good

What to be aware of

Windows are a visible change to your home, and in conservation areas or listed buildings there are restrictions on what you can do. Secondary glazing is often the best option in these situations, as it preserves the original windows while still improving thermal performance significantly.

It is also worth considering windows in the context of your wider energy plan. Replacing windows is expensive relative to the energy savings compared to insulation or draught proofing. If your walls and loft are uninsulated, those improvements will usually deliver more impact per pound spent. That does not mean windows are not worth doing, just that sequencing matters.

If your existing double glazing is in good condition, the gains from upgrading to triple glazing are relatively modest. The biggest improvements come from replacing single glazing or failed double-glazed units.

How Furbnow approaches windows

We assess your windows as part of the whole-house survey, looking at their current condition, thermal performance, and how they fit into the broader improvement plan. Our PAS2035-certified retrofit coordinators will tell you whether window upgrades are the right priority for your home, and which approach makes sense given your budget and any planning constraints.

If window upgrades are recommended, we coordinate the work alongside other improvements so nothing is done in the wrong order.

Understand your options before you commit

A Furbnow home energy plan assesses your windows alongside the rest of your home, so you know whether upgrading them is the right priority and which approach makes sense.