Frequently Asked Questions

Yes. UltraGlass is a FENSA-registered company. All replacement window and door installations are notified to FENSA and you will receive a FENSA certificate upon completion, confirming your installation complies with UK building regulations. This is required when selling your home.

We cover all London boroughs and the surrounding Home Counties. From Central London and the City to outer zones including Richmond, Bromley, Enfield and beyond. If you're unsure whether we cover your area, please call us or send an enquiry and we'll confirm within a few hours.

Every UltraGlass installation is backed by a 10-year written guarantee covering both materials and workmanship. This is transferable if you sell your property, adding genuine value at the point of sale. Copies of our guarantee documentation are available on request before you commit.

Yes. Our double and triple glazing products carry BFRC (British Fenestration Rating Council) energy ratings. Our highest-performing units achieve an A+ rating. All products meet or exceed the minimum energy efficiency requirements set by UK building regulations.

Secondary glazing adds a new inner pane inside your existing window without removing or replacing the original frame. This is ideal for listed buildings, conservation areas and original sash windows you want to preserve. Double glazing replaces your existing window frame entirely with a sealed two-pane unit. It offers superior thermal performance but requires planning consent in conservation areas.

For acoustic performance, secondary glazing is often superior to standard double glazing — particularly for low-frequency noise such as traffic and road hum. The larger air gap between your existing window and the secondary pane provides excellent sound insulation. We offer acoustic glass options that can achieve up to 54dB reduction in noise levels.

Yes — and this is one of the most common applications we carry out in London. Our vertical sliding secondary units are specifically designed to work in harmony with traditional sash windows, allowing both the primary window and secondary panel to operate independently. The result looks entirely sympathetic with the original architecture.

Glass specification varies by application and performance requirements. Standard double glazed units use 4mm toughened panes with a 12–16mm argon-filled cavity. For acoustic applications we use asymmetric pairings (e.g. 6.4mm laminated + 4mm) to maximise noise reduction. All specifications are confirmed at survey stage and detailed in your written quotation.

Most residential installations — covering an average of 6–10 windows — are completed within one to two days. Larger properties or commercial projects may require additional time. We always confirm a clear, realistic timeline at your survey so you can plan accordingly.

We ask that a responsible adult is present at the start of the day to grant access and at the end to sign off the completed work. You don't need to stay home throughout — our teams are trusted, vetted professionals. We'll always call ahead the evening before to confirm the start time.

We take great care to protect your home during installation. Our teams use drop sheets, overshoe covers and seal off working areas from the rest of the property. All waste and packaging is removed at the end of each day. We leave your home as we found it — only with better windows.

Very little preparation is needed. We ask that you clear the immediate window sill area and move any fragile or valuable items away from the windows being worked on. We'll handle everything else. If parking permits are required for our vehicles, we'll let you know in advance.

Costs vary significantly based on the number of windows, the type of glazing specified and your property's requirements. All quotes are free and provided in writing after a survey. We don't publish generic price lists because every property is different — and a figure without a survey is simply a guess. Book your free survey and we'll give you a clear, detailed price within 48 hours.

Our glazing solutions can reduce heat loss through windows by up to 60%. For a typical London home with single-glazed windows, this can translate to energy bill savings of £150–£400 per year. We'll provide an indicative saving estimate as part of your survey report based on your property's specific profile.

Please contact us directly to discuss payment options. We work with a range of clients from single-window residential projects to full-building commercial programmes, and we're happy to discuss payment structures that work for your situation.

Yes, on multiple levels. Quality glazing improves your EPC (Energy Performance Certificate) rating, which directly affects both property value and mortgage eligibility under the growing number of green mortgage products. It reduces energy bills from day one and often pays back within 5–8 years. In London, where period properties dominate, good secondary glazing also protects the character of your home while delivering all the benefits of modern thermal performance.

Yes. We offer conservatory roof glazing upgrades that dramatically improve thermal performance. Depending on your existing structure, options include replacing polycarbonate panels with glass, fitting solar-control or self-cleaning glass, and upgrading to thermally broken frames. Each solution is specified based on a full site survey.

High-performance glazing is one of the most effective upgrades for improving conservatory usability. The right glass specification will keep the space cooler in summer (solar control) and warmer in winter (thermal performance). Many of our clients tell us their conservatory has become one of the most used rooms in the house after our glazing upgrade.

Like-for-like glazing replacements within an existing conservatory frame generally do not require planning permission. However, if you're in a conservation area or have a listed building, some changes may be subject to permitted development restrictions. Our surveying team will advise on any planning considerations as part of your free survey.

Yes. Secondary glazing is the approved solution for most listed buildings as it is reversible, does not alter the external appearance and preserves original windows. Historic England guidance actively supports secondary glazing as the preferred approach. We have an extensive track record working on Grade I and Grade II listed properties across London.

For internal secondary glazing on listed buildings, listed building consent is generally not required as it is a reversible internal alteration. However, planning requirements vary by local authority, and we always recommend confirming with your LPA before proceeding. Our team has experience navigating this process and can assist with guidance and supporting documentation where needed.