We supply and fit timber double glazing in Clerkenwell, with made-to-measure wooden windows for period and modern homes. This page is for homeowners who want the warmth and look of real wood with modern glass and seals. You will learn about the woods and styles we offer, how the windows are built, what drives the cost and how to care for them.
Every job is signed off under FENSA and has a 10-year guarantee. To see other frame types, visit our double glazing windows page, or go back to our double glazing home page.
Why Choose Timber Windows
Wood has framed British windows for hundreds of years. It still has a lot going for it.
- Look: real grain and fine mouldings that plastic cannot copy up close.
- Heat: wood is a natural insulator, so the frame stays warm to the touch.
- Repair: a damaged part can be cut out and spliced, rather than the whole window replaced.
- Planning: timber is often the only frame allowed on listed buildings and in many conservation areas.
- Source: wood from managed forests is a renewable material.
The trade-off is upkeep. Timber needs paint or stain every few years to stay sound. Modern factory finishes last far longer than old site paint, but they still need care.
Woods and Finishes We Offer
We use engineered timber made from layers glued together with the grain running in turn. This makes the frame stable, so it is far less likely to twist, swell or split than a solid plank.
- Engineered redwood or pine: a softwood that takes paint well. It is the most common choice for painted windows.
- Accoya: a treated softwood that barely moves with damp and resists rot for many decades.
- Oak: a dense hardwood with a strong grain, best left with a clear or light stain.
- Sapele and meranti: tropical hardwoods with a rich colour, from certified sources.
Finishes are sprayed in the factory in several coats. You can choose any paint colour, from heritage whites and creams to greys, greens and black. Stains show off the grain. You can also have one colour outside and another inside. Ask us for FSC or PEFC-certified timber if a chain of custody matters to you.
Styles of Timber Window
We make timber windows in the main British styles:
- Box sash windows: the classic vertical slider on weights or spiral balances, for Georgian and Victorian homes.
- Flush casements: the sash sits level with the frame for a neat, cottage look.
- Storm-proof casements: the sash laps over the frame for a strong weather seal.
- Tilt and turn: the inward-opening style, ideal for flats and upper floors.
- Bay and bow windows: built from several units joined to the shape of your bay.
Glazing bars can be true or bonded to the glass, with slim units that keep the bars fine. Horns, run-through sashes and putty-style beads help match an original front.
How Our Timber Windows Are Built
Each window is made to the size we measure at your home. The joints are glued and pinned, then the frame is treated against rot before any paint goes on.
A standard unit includes:
- a sealed glass unit with argon gas, a warm edge spacer and a low-E coating;
- rubber seals set into grooves in the frame;
- multi-point locks on casements, or sash locks and restrictors on sliders;
- internal beads, so the glass is held from the inside;
- trickle vents where the old windows had them.
A good timber window can reach a whole-window U-value of 1.4 W/m²K or less, which meets Building Regulations Part L for replacements. For a lower figure, many timber frames can take triple glazed units. See our triple glazing page for the options. In conservation areas, slim double glazed units let us keep fine glazing bars and still meet the rules.
Planning, Listed Buildings and Building Regulations
Timber is often the material planners ask for, but there are still rules to follow.
- Listed buildings: you need listed building consent before any change to the windows. Some councils accept slim double glazing; others ask for repair or secondary glazing.
- Conservation areas: some streets have an Article 4 direction. This means planning permission is needed to change front windows, even like for like.
- Other homes: like-for-like timber windows rarely need planning permission.
All replacements must meet Building Regulations for heat loss, safety glass and fire escape. As FENSA members, we self-certify the work and send you a certificate. We can also help you put together the drawings and details that the council asks for.
What Drives the Cost of Timber Double Glazing
We do not publish fixed prices for timber windows, as each one is made for its own opening. The main factors are:
- Wood: hardwoods and Accoya cost more than engineered softwood.
- Style: box sashes take more work than casements.
- Size and number: bigger and more windows mean more material and time.
- Glazing bars and details: true bars, horns and mouldings add cost.
- Glass: slim units, triple glazing, acoustic or safety glass.
- Finish: two-tone paint or special stains.
- The opening: stone sills, lintels or repair to brickwork.
For more on how window prices are worked out, see our double glazing prices page. Every job gets a written, fixed quote after a free survey, with the payment stages set out in it. You can ask for your quote here.
Timber or uPVC?
uPVC costs less and needs almost no upkeep. Timber looks and feels more authentic, can be repaired, and is often the only choice on period fronts. Wood-grain foils on uPVC can look close from the street, but not up close. If you are torn, our uPVC double glazing page sets out what plastic frames offer. We are happy to bring both to the survey so you can compare.
Fitting and After-care
We take out the old windows, check the openings, fit the new frames on packers and fix them to the wall. Then we seal and finish them inside and out. Most homes take one to three days. The full process from survey to after-care is on our how we work page.
To keep timber in good shape:
- wash the frames twice a year with mild, soapy water;
- check the paint each spring, and touch up any chips at once;
- repaint or re-stain every few years, as the finish maker advises;
- oil hinges and locks once a year;
- keep the drain slots and sills clear.
Frequently Asked Questions
How long does timber double glazing last?
Well-made timber windows can last for many decades. Engineered wood and modern factory finishes make a big difference compared with older windows. The key is upkeep: keep the paint sound, deal with chips quickly and keep water from sitting on the sills. The sealed glass units have their own life and can be swapped without changing the frame.
What upkeep do timber frames need?
Wash them twice a year with mild soapy water and check the finish each spring. Touch up any chips or cracks before water gets in. Repaint or re-stain every few years, as the finish maker advises. Oil the hinges and locks once a year, and keep the drain slots clear. A little care each year saves costly repairs later on.
What colours can you get for timber double glazing?
You can have any paint colour, from heritage whites and creams to greys, greens and black. Stains range from clear to dark oak tones and show off the grain. You can also have one colour outside and a different one inside. We bring colour samples to the survey, so you can see them in daylight against your walls.
Can timber double glazing cut outside noise?
Yes. Timber is dense and the frames seal well, so they help keep street noise out. The glass does most of the work, though. For a busy road we can fit acoustic glass, which has a special layer to soak up sound. Triple glazing and wider gaps between panes also help. Good seals all round the sash finish the job.
Does timber double glazing add value to a home?
On a period home, good timber windows in the right style help keep its character. That appeals to many buyers and avoids problems with planners. On any home, new windows with a valid certificate and guarantee make a sale go more smoothly. Keep your FENSA certificate and guarantee papers safe, as a buyer's solicitor will ask for them.
