Spring Balance Timber Sash Windows

Spring Balance Wooden Sash Windows in Hidden and Visible Options

Our spring balance timber sash windows combine classic proportion with modern engineering. Designed for smooth operation and long-term reliability, they’re ideal for both period-style new builds and renovation projects where cords and weights are impractical.

Hidden Spring Balance Sash Windows

Our most popular design features a concealed spring mechanism integrated within the sash and frame, delivering the appearance of a traditional sash window without visible cords or weights.

The result is a clean internal reveal, ideal for modern interiors or new-build specifications that call for flush reveals. Every sash is precision-balanced to ensure smooth operation, reliable sealing, and long-term durability.

Key Features:

Concealed spring mechanism hidden within frame and sash
Factory double-glazed: 4 tough Low E / 16 Argon / 4 Clear (Part L compliant)
Internal glazing for improved security and easier maintenance
Fully weather-stripped for excellent acoustic and thermal performance
Engineered European Redwood as standard with hardwood cill
Key-locking sash catches and lifts in brass, satin chrome, or polished chrome
Restrictors and top latch in polished chrome
Spray-finished in RAL 9016 or any RAL colour using a durable microporous system
Centre-pane U-value of 1.1 W/m²K

Design Flexibility

All our spring balance sash windows are made to order, with flexible configurations for single, double or triple sashes (Venetian layout). Choose from a range of glazing bar designs including Ovolo or Lamb’s Tongue profiles in widths of 17 mm, 20 mm, 22 mm, 24 mm and 36 mm.

Each window is precisely measured and manufactured to achieve a perfect fit and consistent detailing across your project.

Visible Spring Balance Sash Windows

Our Visible Spring Balance sash windows offer the same reliability and smooth operation, with the spring balance mechanism positioned externally within the side channel.

This option is often specified by developers and builders who need a cost-efficient sash window system without compromising on quality.

Key Features:

Visible spiral spring balance system
Engineered European Redwood with hardwood cill
Factory double-glazed 4 tough Low E / 16 Argon / 4 Clear
20 mm Ovolo glazing bars available
Internal beading for secure glazing and easier glass replacement
Weather-sealed and spray-painted in a microporous finish
Centre-pane U-value of 1.1 W/m²K

Our Spring Balance Sash Windows

Timber Options

Our sash windows are made from multi-layer engineered timber for strength, stability, and resistance to movement. Each timber type offers its own character and performance level to suit different projects and budgets.

Engineered European Redwood – standard softwood for stability and performance.
Meranti – dense and durable hardwood with a fine grain and consistent texture.
Sapele – strong, stable hardwood with rich colour and tight grain pattern.
Oak – premium hardwood option.
Accoya – ultimate dimensional stability and 50-year rot-free guarantee

All timbers are multi-layer engineered to resist twisting and warping.

Glass Options

We offer a choice of high-performance glazing to meet a range of design, energy, and acoustic requirements. Each unit is factory-sealed and tested for durability, ensuring long-term clarity, insulation, and protection for your home or project.

Standard Double Glazing (4 / 16 Argon / 4 Low E) – Part L compliant
Vacuum Glazing – ultra-slim 8.3 mm units with centre-pane U-value 0.4 W/m²K
Acoustic Glass – enhanced noise reduction
Obscure Glass – satin, reeded, or patterned styles for privacy
Decorative Glass – stained, bordered, or etched designs available on request

Ironmongery

We supply a range of durable, high-quality fittings that complement both traditional and contemporary interiors. Each component is tested for strength, ease of use, and long service life, giving you the flexibility to match finishes across your project.

Polished Brass, PVD Brass, Satin Brass, Antique Brass, Polished Chrome, Satin Chrome, Antique Pewter, Oil Rubbed Bronze, Matt Black

Additional PAS 24 security hardware available for new-build compliance.

We also work with leading architectural ironmongery suppliers if you’re looking for a more refined finish.

Downloads

Access detailed resources to help plan and specify your project.
Our technical drawings include typical sections and elevation details for both hidden and visible spring balance sash windows.

Our quality & service are very important to us…

What Our Customers Say

We’re proud to be rated Excellent on Trustpilot, with genuine feedback from our clients who have chosen our timber windows and doors windows.

"After spending a year searching for the right company to replace our sash windows in a conservation area, we finally found Brett at Sash Window Shop. Brett was professional, and refreshingly transparent - enabling us to feel confident we were in good hands. Brett provided clarity on the style and quality of Sash Window Shop's workmanship. He helped us navigate complex conservation area requirements, explaining all technical aspects clearly. What truly set him apart was his ability to communicate effectively throughout the entire project, with detailed pricing breakdowns to clear timelines..."

Jean Baptiste Hallaire

10 Oct 2025

"I wanted a solid wood bespoke wooden door with windows and struggled to find what I wanted in North London. I found Sash Windows online and from the moment I contacted them I was impressed. My experience with Brett and Sash window team was outstanding. Brett spent so much time and effort understanding what I was looking for and giving advice, making amendments and offering an honest quote. He is extremely knowledgeable... "

Helena Tryphonides

12 Sept 2025

"I would highly recommend Sash Window Shop. We have just replaced all windows of our Victorian terrace with traditional hard wood sashes and the result is excellent. Brett was fantastic throughout the process, and guided us through the necessary planning applications and kept it very stress free. The team who installed the windows were brilliant - friendly, efficient, clean and tidy, and ultimately did a great job fitting the windows. Brett visited during the installation to make sure everything went smoothly. The windows themselves look wonderful and are very high quality - the difference is amazing."

Thomas Powell

12 Jun 2025

"We have just had Brett and his team back for the second phase of replacing our old Victorian sash windows. Both experiences went really well. The windows are really well made and of high quality. The customer service between Brett and ourselves was excellent. The team that installed the windows were brilliant too. They were fast, tidy, meticulous and friendly too. We will be getting them back for a 3rd phase soon."

Samantha

3 Mar 2025

"We would highly recommend Sash Window Shop after a great experience from start to finish. Brett was incredibly helpful and presented multiple options for doors and windows to our extension as we were keen to compare costs on differing specifications. Attention to detail and product quality is exceptional and the team of fitters were professional and meticulous. Thank you to the team for ensuring the job was completed to very high standards."

Coleman

28 Feb 2025

"From beginning to end, the entire process was handled with great attention to detail. Brett guided us through all the available options and even introduced ideas we hadn't considered. The quality and finish of our Accoya windows were outstanding. The installation took place over a few days, and the workers were meticulous and professional, delivering excellent results. I would 100% recommend."

Chris Temmerman

21 Jan 2025

"This is the second time we've used Sash Window Shop as we were impressed with the genuine customer service, appearance and effectiveness of the windows, and professional installation. We can proudly say we have replaced all single-glazed windows and doors of our terraced house with them. Brett was keen to ensure our satisfaction and delivery of a high quality product and we would not hesitate to recommend."

Mallory

12 Sept 2024

"We had a builder measure and fit the window, however the rep from the company came our and checked the measurements - the service was excellent. When they arrived I believe they look better than I had hope for! Very happy customer"

Nick Collett

13 Jun 2024

"I ordered a large sash window from The Sash Window Shop, the communication I received from my first enquiry to delivery was first class. The window was delivered on time and the quality of the window is excellent. I would defiantly use The Sash Window Shop again and would highly recommend."

Philip

13 Jun 2024

"I've recently had Sash Window Shop replace my two timber sash windows (like for like). The process was a pleasure: fast and competitive quote, great communication, timely reminders about payments, lovely looking windows, swift installation. The company representatives were very self sufficient in communicating with the builders onsite and I received full updates over email. I would highly recommend working with them."

Anna

13 Apr 2024

"From initial contact through to delivery the whole experience with Brett and the team at Sash Window Shop has been smooth and professional. We are incredibly happy with our new doors and windows giving our little cottage renovation the fabulous appearance we were looking for. The products are extremely well made with terrific quality furniture a real luxury feel. Thank you so much for giving us a wonderful, friendly and punctual process. Highest recommendation from us to anyone looking for quality windows and doors."

James

20 Mar 2024

We had a really fantastic experience with Sash Window Shop. Brett and the team could not have been more helpful. Really clear correspondence, always available to chat. Brett came out of his way to show us mock-up windows early in the process which sealed the deal for us. He worked hard to give us a brilliantly competitive quote. Fitting was excellent. Can thoroughly recommend.

Alex

5 Mar 2024

"We worked with Sash Window Shop to replace wooden sash windows for our conservation-area property. Brett and the team were fantastic start to finish - going out of their way to ensure we were happy and felt taken care of. We would thoroughly recommend them and will be contacting them in the future should we have any more window needs."

Nick Manias

6 Feb 2024

"Our experience of working with Brett from the Sash Window Shop was exceptional. He is not only a lovely man but also utterly professional. We absolutely love our new sash windows which were fitted as part of a wider renovation and extension of our house. The windows are wonderful quality and as good as any original. The fixtures and fittings are also of a superior quality. We happily endorse this company with confidence."

Kerry Piears

6 Dec 2023

"I couldn’t be happier with my new bay window sash windows. Thank you to all the team at Sash Window Shop, I felt in very good hands throughout. The room has become so much quieter and warmer now."

Fiona Wilson

5 Dec 2023

"I have no hesitation in recommending Sash Window Shop. The quality of the windows and door is superb and my home is so much warmer and quieter. The neighbours have also commented on how good they look! The customer service was superb from start to finish; a no pressure quote process with Brett followed by professional fitting by Martin, with his expertise and attention to detail to get everything just right. To top it all off, everyone was wonderful to deal with which is often hard to come by."

Richard Gardiner

4 Dec 2023

FAQs

What’s the difference between visible and hidden spring balance windows?

Hidden spring balance windows conceal the mechanism within the frame for a cleaner aesthetic. Visible versions display the spiral balance within a side channel – cost-effective but less traditional in appearance.

Are spring balance windows suitable for conservation areas?

Hidden spring balance models are often accepted in conservation areas when cords and weights aren’t feasible, as they retain authentic proportions and detailing.

What’s the lead time for spring balance sash windows?

Standard double-glazed units: approximately 8 weeks. Vacuum-glazed: 10–12 weeks.

Can I order these supply-only?

Yes, all models can be purchased supply-only or with our full installation service if required.

Get in touch today

We’d love to hear from you!

If you have any questions or would simply like some more information about our high performance timber windows & doors, then simply fill in the form below and we will be in touch.

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