Rock Solid Doors
Got a question? Call us on 0800 540 4366
Click below to check out our Trustpilot and Google reviews
Trust Pilot reviews
Google reviews

Insulating your French doors for winter

French doors have gained a reputation for being somewhat energy inefficient over the years because they are made from such large panes of glass. Although advancements in glazing technology mean the reputation is largely an unfair one,  it may still be true of some older doors. Here at Rock Solid Doors, 

we have put together some tips and tricks to help when considering your French door insulation options during the cold winter months.

Modern doors and windows

Glazing technology has come a long way over recent years and modern doors and windows tend to already be well insulated. Inert-gas-filled double glazing and metal oxide coatings reflect the temperature back where it came from. Modern French doors also have engineered cores that are structurally superior to those from the past. They virtually eliminate any warping of the materials that might have allowed air to flow where we didn’t want it to in the past.

Modern French doors are highly energy efficient and will help maintain your constant temperature of choice and reduce energy bills at the same time. Anything we can do to reduce our individual carbon footprint is surely a step in the right direction.

French door insulation: how to keep your home comfortable all year round

Older doors and windows are among the worst culprits in allowing heat to escape and cold to enter your home over the winter months. Here are some suggestions we think you will find useful in your fight to stay warm.

French door insulation options

If your exterior French doors are older and not quite as energy efficient as modern ones then you have a couple of options to consider:

  • Replace the doors
  • Improve the energy efficiency of your existing doors

This is not really a choice you can make until you have assessed the situation carefully and preferably sought professional advice. If the overall condition of your doors is still decent or finances don’t allow for new ones, then there are some steps you can take. A little expense and effort might give your French doors a new lease of life and prevent them from being an energy-sapping liability. The first is the most drastic in terms of expense but if the structure of your doors is solid, you might want to consider it:

Replace the double glazing

If the seals on your double glazing have perished then the inert gas that helps prevent the transfer of heat will almost certainly have escaped. You will know this has happened because condensation will collect on the inside of the panes of glass and be impossible to wipe off. Although the air that replaced the gas is also an insulator of sorts, it is much less efficient and the effectiveness of the double glazing will be drastically compromised. Units with failed seals are, unfortunately, irretrievable in terms of fixing. However, the surrounding structure may be perfectly solid and able to house new glass effectively.

Talk to your trusted expert and ask their opinion on this matter. It may be that the structural integrity of the surrounding doors was a contributing factor to the failure of the units and if

you merely replace them, you will face the same problem again before long. At this point, you should replace the doors entirely.

Check the weather stripping

At the edges of your doors, you will see lengths of weather stripping. These compress when closed and create an airtight seal that keeps out draughts. Constant compression/decompression over time and changes in moisture and temperature can cause these strips to perish and cease functioning correctly. Luckily, it is a simple task to replace them and once applied the replacement strips should perform just like new.

Use draught excluders

f you have draughts coming through your French doors then you are probably already well aware of them. Check to see if you have any new ones using your hand or even a naked flame that will flicker if air passes over it. Use whatever suitable materials you can to block the cold air, preferably:

  • Felt
  • Rubber
  • Heavy curtain material
  • Polystyrene foam

Create makeshift draught excluders until you are able to deal with the wider issue and the results will be noticeable.

Install thermal curtains or blinds

Snug curtains are a game-changer when it comes to containing the warmth in any room and can form a very effective barrier to any cold air that passes your French doors. Remember to open them and allow the sun to fall on the room whenever you can.

Contact us

Here at Rock Solid Doors, we cover all of London and the Home Counties and are ready and waiting to discuss your French door insulation options and other requirements with you. All our prices include fitting and VAT costs and come with a 10-year guarantee.

We are a family business and pride ourselves on our friendly, professional attitude, so get in touch today and we can work together to keep the winter at bay.


Nice people to do business with

“We are very pleased with the door great service nice people to do business with thanks dave”
See all testimonials
Rock Solid Doors Ltd
Creighton Ave, St Albans, AL1 2LG
0800 540 4366
Terms and conditions
Rock Solid Doors
Rock Solid Doors
63 Google reviews
Graham Kidd
Graham Kidd
2 November 2023
100% recommend Paul and Harry a great father and son team! I'm so pleased that we used them to supply and fit our new front door. Straightforward to deal with from start to finish and communication throughout was excellent. They are extremely knowledgeable and were able to offer advice and suggestions when we were choosing the door we wanted. Nothing was rushed during the installation with great attention to detail. They took away our old door and frame and left everything clean and tidy at the end of the job. Thank you, Harry, for taking the time to go through everything with us at the end of the job, much appreciated. I would not hesitate in using Paul and Harry again. Thank you both so much, we are so pleased!
Andrew Brant
Andrew Brant
30 October 2023
Had a door fitted today. Extremely happy with the quality of the finish, attention to detail. Left site clean and tidy. Very impressed. Would highly recommend
Daniel Ashworth
Daniel Ashworth
6 October 2023
Had a door fitted by these very friendly chaps about 18 months ago. We're very happy with it. When an issue arose with the mechanism, they came out and fixed it in about 5 minutes and it's as it if is brand new again. Very pleased, would highly recommend.
L Edwards
L Edwards
2 October 2023
Communication with Paul was faultless throughout. He was polite, knowledgeable and efficient. Harry and Paul installed our new door, problem solving along the way. The finish was neat and tidy and they offered us excellent after sales service aswell. Would highly recommend.
22 September 2023
Highly recommend. We had our front door fitted by this lovely team. They were friendly, helpful, willing to listen to me debate options and provided helpful advice for choosing the right door for us. When he had a slight issue (no fault of their own) they came out to us the very next day and sorted it. Such a good supplier to work with!
Ed Barkham
Ed Barkham
21 September 2023
Brilliant service. No hidden costs or fees and no heavy sales tactics. Very open and clear from the start, and they worked really hard to fit a great new door in our thinner than average doorway! Great value and great result. Will be recommending to all.
fiona richards
fiona richards
10 September 2023
Highly recommend Rock Solid doors. We have used this friendly family company several times and have recommended them to others who have been equally impressed with the high standard of work and the product. We have received quick service and found them to be very reliable knowledgeable with no hard sell. The installations have been carried out professionally and they go the extra mile to ensure you are happy with everything. The external doors are robust and we are impressed with the quality of the product.
James Cooper
James Cooper
24 July 2023
Faultless customer service from a fantastic company to do business with. From start to finish it’s been a pleasure buying composite doors from Rock Solid Doors – in fact, we were so impressed with the front door and installation service they provided (we opted for a Solidor Ludlow 2 with 2 x fully glazed side lights) that we got them back to supply our utility door (Windsor Solidor – fully glazed) shortly afterwards. Paul dealt with our initial queries promptly, came to measure on site and provided a competitive quote very efficiently. These guys are first-rate craftsmen and know their stuff: evidenced by working around a couple of quirky construction issues without any problem – leaving us really impressed with the end product. It’s great to come across a local business that takes pride in what they do, going the extra mile for customer satisfaction – we cannot recommend Rock Solid Doors highly enough! Thank you Paul and Harry!
Simon Gould
Simon Gould
25 June 2023
Brilliant service from Paul at Rock Solid; our letter box seal had gone causing a slight leak - he responded immediately, attended this week and fixed with a new gasket. Would highly recommend the product and the service.
Lidia Duncan
Lidia Duncan
16 June 2023
I ordered my Vogue Rock door with the Ocean glass from Rock Solid Doors at the end of 2021. I had a number of criteria when searching for my new entrance door. It’s ability to insulate had to be A rated. I also wanted it to have a good quality locking mechanism that is smooth in action. My new door needed to be modern with a pane that lets plenty of light in and thus goes lower than the half line on the door, while leaving sufficient height for the letter box, so it is sufficiently high to be comfortably reached by our postman. The Vogue Rock door provided all that and more. I love sailing and the Ocean glass design evokes the lines of a sail in a beautifully minimalistic fashion. It also makes the door look unique, which is always a bonus. During my search for the perfect door I had lots of technical questions too. Only Paul and his colleague from Rock Solid Doors were able to answer all my questions and provide a door that offered what I was looking for. They supplied and fitted my new door in early 2022. My heating bill has gone down noticeably, as a result. With the golden oak wood grain on the outside, my door looks beautiful and elegant. Everyone who comes to the house for the first-time comment on it. The multi-locking mechanism has a smooth action and it is easy to use. The white wood grain on the inside finishes off the hallway like a designer window and door in one. Paul and his colleague went out of their way to make sure that I have the door and the finish just, as I wanted and that it worked seamlessly there on. We could not be happier. Thank You!