Replacement Sash Windows & Doors

New Wooden Sash Windows. Bespoke Timber Doors

Bespoke period windows & doors, constructed the traditional way. 50 year anti-rot guarantee if the windows and doors are made from Accoya WoodTM

Incorporating time proven construction methods, such as mortise and tenon joints, combined with modern advances like Accoya wood ensures that our bespoke joinery is built to last a lifetime. 

Bespoke period window | sash window specialist berks, london & south

Replacement sash windows made to measure. From a single rotten window sash to an complete replacement bay window, if the wood has rotten past economic repair then we offer custom made timber replacement windows & doors.  Authentically copied from the original frames by carefully replicating the original horn shapes, moulding and sectional details.  Our Authentic Replicas are suitable for conservation areas and listed buildings.

Traditional sash window construction

The Edwardians and Victorians perfected the construction of wooden sash windows, so structurally we build them just as they did. Authentic replicas.  Our modern sash windows only differ from the originals by using modern glues, built-in weather seals and improved glass technology. 

Whilst there are cheap sash windows on the market they rely on cost cutting methods that result in them generally only lasting 15 – 20 years.  Our glued and wedged mortise & tenon joints, bonded with modern glues, ensures that our joinery is of the highest quality possible and built to last.  

Bespoke Timber Windows & Doors | Sash Window Specialist UK & AU

Our replacement period window & door service includes:

  • Survey of the existing frames
  • Removal of the old windows
  • Replacement replica joinery
  • Architraves, nosing, liners and beading.
  • Optional paint finish
  • All replacement joinery includes draught seals as standard.

Blending the latest advances in building technology into heritage homes

bespoke French windows / french doors | double glazing & draught seal

accoya wood for sash windows

Accoya® wood is the perfect material for most timber window frames and external wooden doors. 50 year anti-rot guarantee

  • Eco friendly
  • Light weight
  • Extreme durability
  • Insect barrier
  • Dimensionally stable

Accoya® wood represents a major development in wood technology. It enables the consistent supply of durable, non-toxic, dimensionally stable wood. This makes it an ideal material for manufacturing high performance, exterior timber products.  Accoya is manufactured through the acetylation of plantation grown softwood. For over 80 years this has been the gold standard in the academic field of wood science. A breakthrough in closed-loop engineering, culminating in 2007, led to the first commercial scale production of the product in the world.

Period windows and doors made with Accoya have a 50 year guarantee, giving complete confidence that Accoya® windows and doors will stand the test of time. An Accoya® wooden window or door is developed to excel in external applications, even in challenging conditions.

Bespoke joinery is also available from a range of other premium timbers.   Guide to sash window timber

Redwood pine timber used for wooden sash windows, casement windows and doors. Douglas Fir premium softwood timber used for wooden sash windows, casement windows and doors. Oak hardwood timber used for wooden sash windows, casement windows and doors. Meranti hardwood timber used for wooden sash windows, casement windows and doors. Mahogany hardwood timber used for wooden sash windows, casement windows and doors. Jarrah hardwood timber used for wooden sash windows, casement windows and doors. Accoya modified softwood timber used for wooden sash windows, casement windows and doors. Choose Accoya for long life, durablity and eco friendly.


Wide choice of glazing

  • Argon filled DGU for better energy efficiency
  • Acoustic DGU configuration
  • ‘Low E’ energy efficient glass
  • Etched or patterned glass
  • Safety Glass
  • Laminated Glass
  • Float Glass
  • Reclaimed heritage glass
  • Slimlite units or duplex bars
  • 5 – 16 mm spacer bars depending on the sash thickness

Window Security & Hardware

We offer a wide range of sash window hardware options, available in variety of finishes.

Replacement windows and doors that reflect a bygone era; both in looks and manufacture techniques.  

Bespoke Timber Windows & Doors | Sash Window Specialist UK & AU

Our sash window workshop manufactures bespoke timber windows & doors in any style, constructed using traditional mortise & tenon joints.  Suitable for conservation areas and listed buildings.

Bespoke Timber Windows & Doors | Sash Window Specialist UK & AU
Bespoke Timber Windows

Draught seals are machined into the timber components to become an integral, practically invisible part of the windows or door.  Brush draught seals are the best option for a sliding sash window but compression weather seals are better suited to doors.

Sealing draughts in your home will return significant savings in heating and cooling costs, as up to 25% of heat is lost via air leakage in a typical home.

Bespoke period sash windows can reduce the draughts by almost 90%, therefore significantly reducing the air cooling or heating requirement needed for the room.  Warm or cold draughts make air cooling and heating systems work harder and make occupants feel uncomfortable, often adjusting room thermostats to compensate.  

Wood is a natural insulator

The natural insulating properties of timber make this an extremely energy efficient building material.  Timber window frames are highly energy efficient as they do not conduct heat. 

Timber windows help to lower your carbon foot print. 

Wood is a sustainable building material, derived from a renewable source. Any home owner choosing green living should consider preserving or reinstating timber windows.    

How Does low-emissivity glass work?

low e glass for period casement and sash windows

Low-e glass has a special coating which is a poor radiator of heat and does not allow heat to be transferred through the glass. In winter, heating is reflected back indoors; in summer heat from the
sun is reflected away, keeping the room cooler

UK – FENSA, Document L & The Building Regulations?.