Heritage Slimline Double Glazing

We use heritage slimline double glazed units for existing sash and case windows. These state of the art units conserve energy, reduce heating bills, and minimise condensation issues.

By using and maximising the latest technology, our slimline heriate units have a small cavity or space between the panes. The addition of a selected insulating inert gas into the cavity ensures low U-Values that are compliant with building regulations.

The U-Values of our units are comparable or better than U-Values in standard double-glazed units.

Our heritage double glazed units are constructed with a warm edge spacer to increase the U-Value, low emissivity glass to reflect the heat back into the room, and low conductive inert gas to ensure that the maximum possible insulation is obtained. The unique small cavity and small perimeter seal provide the best possible insulation available today.

Fitting heritage slimline double-glazed units to traditional timber sash and case windows offers a transformative blend of thermal performance and architectural preservation.

In Scotland’s often harsh climate, these ultra-thin units—typically featuring a 4mm to 8mm gas-filled cavity—significantly reduce heat loss compared to original single glazing.

By lowering U-values from approximately 5.0 to as low as 1.2, they minimize cold draughts and internal condensation. This upgrade creates a more comfortable, energy-efficient living environment while substantially reducing annual heating costs for homeowners.

Crucially, heritage slimline units are designed to maintain the aesthetic integrity of historic Scottish properties. Their narrow profile allows them to be retrofitted into original timber sashes without altering the delicate glazing bars or traditional sightlines. This makes them a preferred choice for conservation officers and planning authorities throughout the country.

Because they eliminate the “double reflection” seen in standard units, they provide the authentic look of single glass while enhancing sound insulation and overall property value.