glass extensions

Glass Extensions

Glass Extension
Glass Extension
Glass Extension
Glass Extension
Glass Extension
Glass Extension

Buy Now Pay Nothing until Next Year

Pay nothing for 12 months. Available on all product lines, settle in full prior to the end of the 12 month deferral period and pay no interest. A £29 exit fee applies.

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19.9% APR Representative

Terms and Conditions

Representative example: Cash price of goods £2748, 10% deposit £274, total amount of credit £2474. Duration of agreement 132 months (including 12 month deferral period) Total amount if paid in full before 12 months £2474 + £29 exit fee. Or then 120 monthly instalments of £53.19, rate of interest 19.90% pa (variable), total amount payable is £6656.80, 19.9% APR Representative. Credit is subject to application and status. Terms and conditions apply - please contact us for full details.

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KM Windows Ltd glass extensions are bespoke designed to increase your living space and provide a unique extension to your home. The link between your home and your garden which transforms the way we use both of these spaces.

Unlike a typical bygone conservatory, a glass extension can be used all year round.

Having a glazed extension to your home is an investment and choosing who will build your glazed extension is a very important decision. It can be a complex process however our experienced designers will guide you through the decision making process with sound advice, you need to feel that you are selecting a company able to give you the very best products and service and a room built for the future.



Unique CELSIUS performance
glass that reflects
heat away

Celsius Glass

Environmental control
maintaining an ambient
temperature all year round


Dedicated architect
for permitted
development enquiries


At KM Windows we work closely with a dedicated architect who has established relationships with local authorities for permitted development enquiries, lawful development applications, drawings, planning applications, SAP calculations and specialist advice to ensure that your project is managed smoothly.

Cooler in the summer and warmer in the winter

We can design, build and transform your extended living space from concept to completion. Our experienced and time served team of designers, technical surveyor and builders will manage your new home addition in consultation with you throughout.

The advancements in glass technology and the materials we use in your new glass extension will allow you to have the warmth in the winter and the cooler temperatures in the summer that other conservatories fall short of.

We use Celsius performance glass which reflects heat and protects your furniture and fabrics from UV light whilst still letting the natural light in. The glass repels dirt and moisture and virtually keeps itself clean leaving you with more time to enjoy your new glass extension.

Celsius Diagram


Thermal Control

The days of glass extensions being hot in the summer and cold in the winter are long gone. Now you can choose not only the climate but how you want it controlled.

Secure by Design

Our glass extensions are safe with multi-point locking systems as standard on all large opening doors as well as Yale deadbolt and hook-lock system for the ultimate in security, approved to strict standards and endorsed by the British Standards Institute which carries the prestigious kite mark of quality.

swindon upvc conservatory
Lean to

Lean To

The lean to glass extension is also known as a garden room, sunroom or Mediterranean conservatory. The glass to ground model really brings the garden into the home and is still a very popular choice.



With its sharp sleek lines, The Edwardian glass extension is both practical and elegant in design. The combination of traditional design and the maximising of space make it an ever popular choice.

new swindon conservatory


The Victorian glass extension with its angled roof , ornate cresting and finial provide an elegant addition to any home. The immense styling and exceptional quality make it one of the more desirable options available.

Gable End

Gable End

Gable End glass extensions are reminiscent of the grand orangeries and classic conservatories of Days gone by. This type of conservatory enjoys an imposing front elevation with the windows extending to the apex of the roof.

P & T Shaped

P-Shaped & T –Shaped

The layout of these glass extension styles gives you a new dimension in flexibility. With a dynamic sense of presence the P Shaped adds not only more living space – but a touch of class to any home.



The Orangery originated from the Renaissance gardens of Italy. Originally built as a greenhouse and also as a symbol of prestige, wealth and a feature of gardens. Your Orangery complete with lantern roof feature and classic cornice detailing and pilastars will lend a certain wow factor to your home and provide a beautiful space for entertaining and relaxation.