uPVC Sash Windows, Vertical Sliders, Box Sash
Timeless Style, Modern Efficiency
uPVC Sash Windows
Are you searching for top-quality uPVC Sash Windows, Vertical Sliders, or Box Sash windows replicating traditional styles for your period property? Then look no further than our replacement uPVC Sash Slider Window. Our design and installation services are perfect for all-period homes, from smaller Victorian or Edwardian terraced houses to larger Georgian stately homes. Our authentic-looking uPVC Vertical Slider Sash Windows feature Ovolo finishing details, blending modern materials and functionality with traditional design and character.
No Salesman Pressure
At Southeast Windows, we take a unique approach to sales. Our team operates on a non-commission basis, which means you won’t feel pressured to make hasty decisions. We firmly believe in avoiding high-pressure tactics that push you to sign up on the same day or rely on misleading discount deadlines to close a deal. We aim for transparency and strive to inspire you to choose our products based on the quality and longevity we guarantee, giving you peace of mind in your decision-making process.
You are encouraged to take your time, do your due diligence, research, and share your project requirements and concerns with us. We understand that every project is unique, and we prioritise addressing your needs. We are committed to answering your questions and providing clarification, ensuring you feel valued and confident throughout the process. We want you to be happy that you have made the right choice, and we will do everything we can to make that happen.
Maintaining Traditional Style
To maintain the classic style of your uPVC Sash Windows, Vertical Sliders, or Box Sash replacements, we can replicate them with Georgian Bar inserts or Astragal bar on the outside, creating the appearance of multiple glass windowpanes. For a more visually appealing look, we also offer sash horns with a run-through design, which are superior to clip-on alternatives.
Improved Insulation and Design
Many existing uPVC Sash Windows, Vertical Sliders, and Box Sash windows suffer from rattling, draughts, and poor energy efficiency. Advancements in window technology allow us to improve your home’s insulation. Our vertical sliders can achieve U-values as low as 1.2 W/(m²K), enhancing soundproofing and energy efficiency. The design maintains the original box sash window aesthetic, providing a visually pleasing upgrade.
Craftsmanship and Quality Control
Our uPVC replacement Vertical Sliders are crafted using advanced manufacturing techniques and undergo strict quality control throughout the process, ensuring a quality window when completed. The UPVC vertical slider windows significantly improve upon existing box sash windows, offering exceptional performance and durability. Our high-performance PVC-U sliders come in various colours and hardware options, including child restrictors, ensuring they complement any home. We are confident that your new installation will satisfy your expectations.
Weather-Approved Performance Ratings
| Testing Category | Metric Achieved | Industry Classification & Meaning |
|---|---|---|
| Air Permeability | 600 Pa | Class 4 (The highest possible airtightness rating achievable under EN 12207). |
| Water Tightness | 300 Pa | Class 7A (Ensures the window frames stay completely watertight even in highly exposed coastal or hilltop areas). |
| Wind Resistance | 1600 Pa | Class C4 (Proves structural stability capable of withstanding storm-force gale winds up to 115 mph). |
Installation Options
You can choose from various customisation options for your installation. Depending on your preference, you can replace the existing frame architrave with hardwood, softwood, MDF, or uPVC trims. Sometimes repairs may be needed after installation if the original plaster has degraded over time. We ensure the area is ready for decoration once the work is completed.
Hardware Options
uPVC Vertical Slider Sash Windows come with white hardware as standard, but you can customise them with options such as Brass, Chrome, Satin Chrome or Black finishes. Also, Child safety locks can be installed for added security, limiting the sash opening to 100 mm.
Energy Efficiency and Compliance
Our uPVC Vertical Slider Sash Windows have an A+ energy rating, meeting the requirements of Approved Document L for energy conservation. They are also Building Regulation Part B compliant with fire exit status. As a FENSA-registered company, we provide documentation for FENSA self-assessment, and our windows come with a 10-year guarantee for added security and peace of mind.
A vertical slider is our modern uPVC version that opens the same way as a traditional box sash, sliding up and down, but uses spring balances instead of traditional sash weights and cords, giving better energy efficiency and less maintenance while keeping the classic look.
Yes. Unlike original timber sash windows, our uPVC vertical sliders use modern sealed spring balances and weatherproof seals, virtually eliminating the draughts and rattling common with older timber sash windows.
Yes. Our windows are designed to replicate the slim sightlines, proportions and detailing of traditional timber sash windows, including options like Georgian bars, so they suit period and conservation-area properties while giving you modern performance.
Most homes can be completed within a day, though this depends on the number of windows being replaced and the amount of making good required. We’ll confirm an exact timeframe at your free survey.
Want to know More?
Call us today for your FREE, no-obligation quotation or fill out our Contact Form! For the most modern, energy-efficient replacement Windows, Doors and Conservatory with a 10-year Insurance Backed Guarantee for complete home Comfort & Designed to Keep You Warm, Safe, & Secure.
Alternatively, call your local number below to arrange an appointment.
East London uPVC Sash Window: 020 8472 4088 (head office)
South London uPVC Sash Window: 0203 856 6667
North London uPVC Sash Window: 0203 856 6669
Chelmsford uPVC Sash Window: 01245 208 058
Romford uPVC Sash Window: 01708 202 457
Great Dunmow uPVC Sash Window: 01371 704 771
Trust Southeast Windows Ltd to offer elegant, high-quality replacement uPVC sash windows.
