It's Time To Increase Your Custom Secondary Glazing Options

· 5 min read
It's Time To Increase Your Custom Secondary Glazing Options

The Comprehensive Guide to Custom Secondary Glazing: Enhancing Performance Without Compromising Heritage

In the world of architectural preservation and energy effectiveness, homeowner typically face a hard predicament. While modern-day double or triple glazing provides remarkable thermal and acoustic efficiency, installing these systems in period properties, noted buildings, or conservation locations is frequently limited by law or visual considerations. Moreover, the structural stability of older window frames might not support the weight of heavy double-glazed systems.

Custom-made secondary glazing has emerged as the premier solution to this challenge. By installing a discreet, extra internal window behind the existing main window, it is possible to accomplish contemporary requirements of convenience while maintaining the initial character of the structure. This post checks out the mechanics, benefits, and numerous configurations of custom secondary glazing systems.


What is Custom Secondary Glazing?

Secondary glazing includes the setup of an independent internal window frame, fitted on the space side of the existing main window. Unlike mass-produced solutions, "custom-made" secondary glazing is bespoke-engineered to match the precise dimensions, lines, and performance of the initial window.

Whether a structure features large Victorian sash windows, arched Gothic frames, or commercial steel casements, custom-made secondary units are created to be as inconspicuous as possible. They are normally constructed from slimline aluminum frames and high-performance glass, guaranteeing that the visual effect on the building's interior is very little.


The Core Benefits of Custom Secondary Glazing

The choice to set up secondary glazing is typically driven by one of four main elements: thermal insulation, acoustic dampening, security, or heritage conservation.

1. Thermal Insulation and Energy Efficiency

Heat loss through older, single-glazed windows is a substantial factor to high energy bills and carbon footprints.  read more  glazing produces a pocket of insulating air in between the 2 panes of glass. When integrated with modern-day Low-E (low-emissivity) glass, this can reduce heat loss by approximately 60%.

2. Superior Acoustic Performance

While basic double glazing works at keeping heat, it is typically less effective at obstructing low-frequency noise, such as traffic or airplane. Custom secondary glazing stands out in this area due to the fact that of the "air gap." By maintaining a gap of 100mm to 200mm in between the main and secondary glass, the system develops an effective acoustic buffer that can minimize noise levels by up to 50 decibels (dB), efficiently turning a loud city street into a quiet sanctuary.

3. Conservation of Heritage

For buildings with "Listed" status, replacing windows is frequently forbidden. Customized secondary glazing is usually viewed favorably by preparing officers because it is a reversible internal modification. It allows the initial wood or metal frames to remain undamaged on the exterior.

4. Enhanced Security

Adding a second layer of glass provides a substantial physical barrier against burglars. Custom units can be fitted with toughened or laminated glass, which is incredibly challenging to permeate, providing peace of mind for homeowner.


Kinds Of Custom Secondary Glazing Units

Considering that every window is different, a number of setups exist to ensure that the secondary unit does not impede the operation of the original window.

  • Horizontal Sliders: Ideal for casement windows or ribbon windows. The panels slide on incorporated tracks for easy access.
  • Vertical Sliders: Designed particularly for standard sash windows. These units make use of spring balances to mimic the motion of the original sash.
  • Hinged Units: These open like a basic door or window. They are typically utilized when total access to the primary window is needed for cleaning or ventilation.
  • Lift-Out Units: Best for windows that are hardly ever opened. The entire glazed panel can be lifted out of the frame when maintenance is needed.
  • Repaired Units: These are completely connected to the frame and are used in locations where ventilation through that particular window is not necessary.

Comparing Window Solutions

When weighing alternatives for window upgrades, it is handy to see how custom secondary glazing compares to basic replacement windows.

Table 1: Secondary Glazing vs. Replacement Double Glazing

FunctionCustom-made Secondary GlazingReplacement Double Glazing
Aesthetic ImpactMinimal; preserves original exterior.High; modifications the structure's facade.
Acoustic PerformanceSuperior (due to bigger air space).Moderate.
Preparation PermissionHardly ever required (even for noted buildings).Frequently needed in sanctuary.
Installation MessVery little; no structural modifications.Significant; needs removal of old frames.
ExpenseUsually more economical.Can be really pricey for bespoke lumber.
Thermal EfficiencyHigh (similar to double glazing).Very high.

Technical Specifications: Glass and Performance

The efficiency of a custom-made secondary glazing system is mostly identified by the type of glass picked. Specialists typically advise specific glass types based upon the primary goal of the setup.

Table 2: Glass Performance Metrics

Glass TypeMain BenefitSound Reduction (Est)Thermal Improvement
4mm ToughenedSafety & & Basic Insulation35-38 dBModerate
6mm FloatStandard Performance39-41 dBModerate
6.4 mm LaminatedSecurity & & UV Protection42-45 dBGreat
6.8 mm AcousticOptimum Sound Proofing48-52 dBGood
4mm Low-EMaximum Heat Retention35-38 dBExcellent

The Custom Installation Process

To ensure the highest efficiency, the installation of custom-made secondary glazing follows a systematic expert procedure:

  1. Surveying and Measurement: A specialist takes accuracy measurements of the window expose. Out-of-square openings are kept in mind so the custom frame can be produced to compensate for structural shifts in older structures.
  2. Bespoke Manufacturing: The frames are powder-coated to match the interior decoration (standard white, anthracite, or any RAL color) and the glass is cut to size.
  3. Preparation: Existing window sills and reveals are cleaned up. Any essential wood sub-frames are set up to provide a level mounting surface.
  4. Fitting: The secondary systems are protected into the expose. Unique care is required to ensure an airtight seal, as air leakage is the primary cause of bad acoustic and thermal efficiency.
  5. Completing: Perimeter seals are used, and the movement of sliders or hinges is checked for smooth operation.

Regularly Asked Questions (FAQ)

1. Does secondary glazing cause condensation?

If set up incorrectly, it can. Nevertheless, professional custom-made secondary glazing is designed to manage this. The internal unit creates an airtight seal versus the room's warm, wet air, while the main window is allowed to "breathe" a little. This prevents the moisture from reaching the cold outer pane where it would usually condense.

2. Is secondary glazing obvious from the exterior?

Generally, no. Since the frames are slim and aligned with the existing window's conference rails and mullions, they are essentially unnoticeable from the street. This is why they are the preferred option for historical preservation.

3. Can I still open my windows for ventilation?

Yes. By picking the proper kind of system (such as a vertical or horizontal slider), the secondary glazing can be opened in tandem with the primary window to enable fresh air circulation.

4. How long does the setup take?

A lot of domestic installations can be completed within a single day. Due to the fact that there is no need to remove the initial windows, there is very little dust or structural disturbance.

5. Can secondary glazing assist with UV fading?

Yes. By choosing laminated glass for the secondary system, homeowner can obstruct up to 99% of UV rays, protecting furniture, artwork, and materials from sun damage.


Custom secondary glazing represents a sophisticated intersection of modern-day engineering and architectural heritage. It supplies a pragmatic service for those residing in older homes who wish to minimize their ecological impact and delight in a quieter home without sacrificing the historical stability of their property.

By using superior soundproofing compared to basic double glazing and offering a considerable thermal barrier, custom units are a financial investment in both the worth of the property and the quality of life for its residents. For anybody handling the difficulties of drafty, noisy, or secured windows, custom-made secondary glazing stands as the most flexible and reliable upgrade offered on the contemporary market.