Bespoke Double Glazed Sash Windows in London
Preserve the Heritage, Upgrade the Performance
London is defined by its architectural history, from Georgian townhouses in Marylebone to Victorian terraces in Clapham. At MJ Kloss Carpentry, we specialize in bridging the gap between 19th-century aesthetics and 21st-century comfort.
Our bespoke double-glazed sash windows allow you to maintain the iconic “London look” while dramatically improving your home’s insulation and security.
Why Upgrade to Double Glazed Timber Sashes?
Most period homes in London still struggle with original single-glazed units that are draughty, rattle in the wind, and offer little protection against the city’s noise. Replacing or retrofitting these with high-performance double glazing provides:
- Superior Thermal Insulation: Our double-glazed units feature low-E glass and argon-filled cavities, significantly reducing heat loss and lowering energy bills.
- Acoustic Dampening: Block out the hum of London traffic and sirens. Double glazing acts as a powerful sound barrier for a peaceful interior.
- Heritage Compliance: We design slim-profile sashes that meet the strict requirements of London’s conservation areas and listed buildings.
- Enhanced Security: Modern toughened glass and high-quality locking mechanisms provide peace of mind that original single-pane windows cannot.
Our London Joinery Process
We are not a “one-size-fits-all” window company. We are master carpenters who understand that every London opening is slightly different due to centuries of structural settling.
1. Architectural Survey
We visit your property to take precise measurements and document the original mouldings, horn details, and glazing bar configurations to ensure an exact match.
2. Handcrafted in Our Workshop
Your windows are crafted in our local workshop using sustainably sourced hardwoods (like Accoya or Sapele) or engineered softwoods. These materials are chosen for their stability and resistance to the British weather.
3. Precision Installation
Our team manages the entire installation, ensuring a weather-tight seal and smooth operation of the weights or spring balances. We pride ourselves on a clean, respectful worksite—essential for busy London households.
Solving the “Conservation Area” Dilemma
If you live in a conservation area (such as parts of Islington, Kensington, or Richmond), you may be worried about planning permission.
We specialize in Slimline Double Glazing. These units use a narrower gap between the glass panes, allowing us to fit them into traditional-looking timber sashes that are indistinguishable from original single glazing to the untrained eye.
How Much Do Double Glazed Sash Windows Cost in London?
The cost of double glazed sash windows in London varies depending on size, style, materials, and finish. Because each window is made to measure, we provide tailored quotes rather than standard prices.
To get an accurate estimate on double glazed sash windows in London, we recommend arranging a free consultation and site visit.
We’ll discuss your design goals, glazing options, and frame finishes, then provide a detailed written quote.
Frequently Asked Questions
Can you double-glaze my existing sash frames?
In many cases, yes. If your existing “box” frames are in good structural condition, we can often manufacture new double-glazed sashes to fit into the original frames, saving you money and preserving the original fabric of the building.
How long does the installation take?
For a standard London terrace, most installations are completed within 2–4 days, depending on the number of windows and the complexity of the project.
What finish do you provide?
Our windows come factory-finished in your choice of RAL colours. We use high-quality, microporous paints that allow the wood to breathe while providing a long-lasting, low-maintenance finish.
Get a Quote for Your London Project
Ready to eliminate draughts and enhance your home’s value? Contact M.J. Kloss Carpentry today for a free, no-obligation survey of your sash windows. We also offer triple-glazed sash windows for added warmth, sound reduction and security
Call us: 020 8945 3552
Serving North, South, East, and West London.
Give us a call
At MJ Kloss Carpentry & Joinery we are always available to answer any question or query about your home project, big or small. Our phone lines are open from 9:00am to 5:00pm weekdays. We hope to hear from you soon.
