Can Bi-folding Doors be frameless?

Unfortunately you can’t have a completely frameless bi-folding doors as they won’t meet building regulations. As standard all bi-fold doors and any external doors need to meet U-values of 1.8W/m²K (a U-value is simply the measurement of the rate of heat lost through a material). Achievable U-values will depend on the size of the door panel, the type of frame, sealants used and also glazing and glazing coatings.

Bi-folding doors with slim sightlines and sliding corner 

The best way to achieve a near frameless look is to opt for a system with very slim sightlines (which is basically the width of the frame). Aluminium bi folding door systems on the market will tend to have a more contemporary design and often have much slimmer frames, for example Sunfold Systems' SFK70 system, is just 100mm. Quality will play a large part in the stability of the bi-fold doors and the higher quality systems will have been specially designed and tested to be capable of providing the required support whilst also achieving that as near frameless look as possible. Most off the shelf systems will have much thicker bulkier frames as standard such as uPVC. 


Some folding door companies will offer very tall heights without additional support but this has a detrimental effect on the sightlines as they usually need to incorporate some kind of post/additional profile in between the hinge section – this is where their support comes from (as opposed to midrails/horizontal transoms). The effect then when the doors are open is chunky and you also achieve less opening space as the doors can’t fold as flat to one side. 


Frameless systems on the market with a similar concept such as sliding stacking doors (doors which stack to the side rather then fold and slide) will not provide thermal efficiency but tend to be used more for weather protection for areas such as porches or balcony areas where a fully insulated door system acts as a divide.

Top or Bottom Tracks on Bi-fold Doors - What's the Difference?

It's a regular question asked when looking at bi-folding doors, and different suppliers will offer different opinions. So what should you opt for? 

Some suppliers will only offer one or the other largely dependent on their own system’s capabilities and you'll often find that they state that their system will be suitable for the project as a result. However this isn’t necessarily the case and it’s a good idea to base the choice of product and therefore supplier on the structure of the property using the following concept.

As standard bottom running tracks are recommended for standard heights (ie up to 2350mm) as they do not require such structural support at the top of the opening. The plus with this is that this option tends to work out cheaper. They can also have slimmer head profiles than a top hung system so a little more aesthetically pleasing as won't require additional bulk in the frame.

Top hung however is usually recommended when doors are needed to be much taller ie up to 3000mm, or if the system is heavier, for example, if the system has triple glazing further structural considerations will come into play. With such heavier weights, top hung systems will also help to prevent the door weight de-railing the systems. To protect against this a good quality system will offer sprung running gear guides to ensure wheels stay in contact with the track. 

Bi-folding doors are often used to open out large areas so it's really important to choose the best system for your individual project. You don't want to be faced with issues further down the line.

When to Choose your Windows

Making sure you don’t leave it too late to order windows is really important when you embark on your self build project; and budget especially will always be a key consideration, so it’s always advisable to consider the options as early on as possible so that you're prepared for all costs. Typically your window choices can account for up to 20% of the build cost so it's worth making a decision to suit budget sooner rather than later as you can always then amend your design should budget get out of control. But as a key structural element of the project it’s best to ensure they meet with all your requirements as after all you’ll want then to last as long as possible.

Bespoke windows for specific build projects 

The choice in whether opting for standard off the shelf windows or bespoke windows made will also play a key part in the process as for bespoke you will need to allow for longer delivery periods than with ready-made alternatives. The bonus with bespoke is that your build design will determine the size of the windows, however with off the shelf windows, they will actually determine the build design. Your architect will be able to advise you on what is best for your project.

Energy efficiency - check the U-values

The positioning of the window is also important and in most cases windows will be set 30mm back from the front brickwork, although in aid of thermal efficiency some windows can be installed in line with the wall cavity which will provide greater insulation and improve U-values.

Unusual window styles to retain can still retain excellent U-values

 A U-value, which is the measurement of the rate of heat loss through a material, will impact on the energy ratings of the windows. Legislation states that windows have to comply to a U-value rating of 2.0W/m²K to meet building regulations. Achievable U-values will depend on the size of the window panels, the type of frame, sealants used and also glazing and glazing coatings, so by choosing bespoke windows in particular you could potentially lower the rating and save further on long-term energy bills. So by choosing the right supplier and installer in particular you could potentially lower the rating and make additional savings.

Do I need to replace my windows?


If you’re renovating and not sure whether you need replacements or not keep a look out for the tell tale signs:

• Feeling draft through the window resulting in poor insulation
• If the window sticks or no longer holds open
• If weather stripping is missing or peeling 
• Windows are fogged with condensation there could be a problem with sealant
• Exterior damage such as flaking or crumbling specifically on wooden frames or visible damage through other materials
• External noises are loud within the property

It’s always best however to seek a professional opinion relating to whether the windows can be repaired, but there are wide ranging solutions available to help in the interim until windows can be replaced to help with insulating etc.

What to consider before choosing Bi-folding Doors

There’s a lot more to consider than you’d have thought! Here’s a useful list of things you should be thinking about and looking into when buying folding sliding doors (bi-fold doors):

• The architecture of the building and the type of project will have a large influence on the doors you choose

• Take into account what available ie materials, colour and finishes

• Think about opening sizes including height, width and depth. New build projects, renovations and extensions, for example, will allow for the homeowner and architect to draw up plans to incorporate the exact opening size at planning stage. However replacement doors would be influenced by an already established opening size

Bi-folding doors as a complete sliding corner system
- possible because of the building structure

• Building support and whether top or bottom running tracks are best. Bottom running tracks are usually best for standard heights (ie up to 2350mm) as they do not require such a hefty lintel at the top of the opening (this is a cheaper option). Top hung are usually recommended where doors are needed to be much taller ie up to 3000mm

• The surrounding area ie is it a conservation area or is the building listed. Your choice of material could be required to fit with the surrounding area for example

• Choosing the right type of doors is also important, for example in some instances folding sliding doors wouldn’t be an option if folding stacking space was limited or could be obstructed. Sliding doors are always an alternative as allow for wider panel widths minimising frame sightlines however these will only allow for half of the opening width. Folding sliding doors stack to leave a full and complete opening

• Which way does the property face? If you want to make the most of the open living experience then your doors are best to be south facing

• Where is the property? Do you need added protection against bad weather. Sunfold Systems offers marine treatments to protect against coastal environments along with severe weather rated seals and gaskets

• What sort of home are you creating? Are the doors more for aesthetics or does the home need to be super sustainable. Quality doors will always meet the required government standards but options to enhance U-values will be available

• Will the door system need to be straight, cornered or curved (faceted) to accommodate the building design

Faceted bi-folding doors used for curved buildings

• Time scales are important. To ensure delivery of bespoke doors to meet with project deadlines it is advisable to order at an early stage. If they are ready before the project is ready the doors should be able to be held in the supplier’s warehouse, however, if they are not given the required time frame the project could be held up

• Check to see if the doors will require any upkeep or maintenance. The material chosen will play a large part.

Modern & Traditional Front Doors - Which Material is Best?

When choosing your own style front door there are a number of options available and criteria to consider. You’ll need to be looking not only for the best design to suit your house exterior but also at the door’s durability. In particular how it will stand up against changing weather conditions, how it provides the required level of security for your home and how will it also save on those all-important energy bills?

Typical front doors tend to be made from either wood, uPVC, metal (steel or aluminium) or made from composite materials, all of which have their plus points and negatives.

Aluminium panel front door with high insulating core

 Metal doors will tend to be either steel or aluminium doors. The main benefits of both types are that they are incredibly durable, weather resistant, high security and fire rated. Both will be made with a metal panel exterior with a high insulating wooded core; the main disadvantage would be that the metal can dent, but this would be under extreme pressure and fairly easy to fix - there are also kick plates which protect the lower section of the doors if concerned. Specialist coatings are available for both although aluminium will hold up best against weather conditions as steel has been known to rust overtime. In coastal areas in particular where the air has a heavier salt content, specialist marine treatments can be applied to aluminium front doors to ensure longevity. Steel also can’t be combined with a storm door, however, aluminium can without fear of the hazards of heat build-up.

Traditional front door example

 The more traditional option would be wood, usually in oak, cherry, walnut, mahogany or maple etc. Wood doors can prove to be expensive and also risk warping, cracking and deteriorating over time as temperatures and weather conditions change so frequently the wood can swell and move creating problems opening and closing the door and damage the exterior. There are ways round such issues by, for example, opting for durable stains and in particular high gloss screens for painted wood.

Thickness of the wood door will also impact as well as the way the wood is cut; thicker doors will not be affected so easily but this will inevitably push the price up. Wood doors will, however, always require regular maintenance in comparison to the other options on the market. For a cheaper alternative with similar overall look, you could opt for wood veneer. Wood veneer doors will still have a wood core but will minimise warping depending on the quality and thickness of the veneer. Insulating cores will also be available.

uPVC is a very common alternative and maintains a number of advantages as the doors remain rigid no matter the weather conditions. They are classically weather proof and damp proof and also require little maintenance other than cleaning, however, these doors have been known to discolour over time and in some cases direct sunlight has been known to breakdown the material and create cracks. This can be avoided by ensuring the supplier is reputable and that product is of a high quality. The most attractive element to uPVC is that the doors can be very reasonably priced for what you get for your money, but uPVC doesn’t necessarily suit all styles of home, especially if the home-owner wants something a little more traditional or contemporary.

In summary, all front doors whether modern doors or traditional doors have their pros and cons, but the same underlying rule will always apply. Choose quality and you’re much less likely to be looking to replace your front door in a few years.

Quality Folding Sliding Doors - how can you tell they're genuine?

Folding sliding doors (bi-folding doors) can use up a chunk of your door and window budget so you’ll want to make sure that the system and material you choose will pay for itself over the years. But with so many suppliers out there how can you tell if the folding sliding door system you’re looking at lives up to the quality you’ll require?

Best starting point is to do your research by visiting exhibitions such as the National Homebuilding& Renovating Show and Grand Designs. This is a good starting point and a convenient way to see a range of suppliers in one place. However if there isn’t an exhibition near you or doesn’t fit with your time frame you’ll need to visit showrooms yourself so that you can see and test the doors first hand. Look at the quality of the finish and feel how smoothly and easy they open and close. Quality doors won’t jolt, they should glide. Also check the tight fit of the doors when closed to ensure there are no gaps in the door system and that seals are flush.

Quality aluminium bi-folding doors

Special features included within the price such as finger safe gaskets, and security features will help show the quality systems from the basic. In quality systems these should include shoot bolts top and bottom, ideally these should be lockable for added security. Ask what locking systems are included? For example, hinges can be an easy way to break into doors so opt for a system where the hinge pins (which hold the hinges together) are actually locked into their casings. Hinge material is also important as castings can easily smash if attacked with a hammer, Sunfold Systems for example, use an extrusion which is the strongest material. Also look at what upgrades can be incorporated into the system to improve security and thermal efficiency. The more add-ons the higher the performance.

There should also be ranging options in configuration and track types to suit different circumstances. Flexibility in the products on offer will mean specialist attention to detail. This is often the case with bespoke made-to-measure doors.

Bespoke made-to-measure folding sliding doors

Check what the guarantee is on the doors. This should cover frames and mechanisms. The last thing you want is for something to go wrong in the first few years and to not be covered.

Finally the reputation of the supplier will always be a tell-tale sign. Recommendations are always a good way to go. Look at the company’s track record, the longevity of the business is a good tell as to its overall success. Most importantly listen to your contractor for their personal experience and for their advice on who to use and also on which professional bodies the supplier should be a member of. A reputable supplier will always be happy for you to contact past customers (as long as the customer agrees) for first-hand experience to give you more confidence in your choice.

Glass Doors - Options & What to Consider

When looking for external glass doors for a property whether for an extension, renovation or new build there are numerous options on the market to suit a variety of needs. So what are the things that a homeowner needs to consider when thinking of installing glass doors?

Firstly it’s important to decide on the top criteria you want to meet. So for example are you looking for the wow factor, something which will truly make the architecture of your property come to life? Are you looking to save on energy bills and need the top ways to make savings? Or do you have to meet set building regulations to stay in keeping with your area? There are lots of questions to consider.

Firstly, I’d recommend you decide on the overall look you want to achieve and the space which is available. The opening widths and heights will play a large part in the external glass doors or systems you opt for and depending on space, you could choose anything from folding sliding doors (also know as bi-folding doors), patio doors such as sliding doors, sliding stacking doors or through to stand alone single doors or French style double doors.

Aluminium bi-folding doors

There are companies out there which provide standard size door panels whereby you will need to ensure the space caters for these sizes, however, if you’re truly wanting to gain the ultimate wow factor and be the envy of the neighbours, made-to-measure bespoke doors, from for example Sunfold Systems, will fit with your exact needs and requirements. You can then choose the colour, finish and your preferred configuration, opening mechanisms and glazing options for your own tastes.

You can then look at what will best suit your situation. It’s important to discuss with your contractor what is possible to ensure that your external door requirements will meet with building regulations. Building regulations can change depending on your location and in particular in conservation areas. So consider structural support and your choice of frame material as this will impact on the suitability of the system and the door energy efficiency levels which can be achieved. 

A U-value which is the measurement of the rate of heat loss through a material, is a key consideration as this will impact on the energy ratings of the doors. Legislation states that external doors have to comply to a U-value rating of 1.8W/m²K to meet building regulations. Achievable U-values will depend on the size of the door panel, the type of frame, sealants used and also glazing and glazing coatings, so by choosing bespoke doors in particular you could potentially lower the rating and save further on long-term energy bills.

Specialist marine treatments for bi-folding doors on the coast

There are other ways to maintain heat transfer and protect against the elements through your choice of doors. If choosing folding sliding doors, for example, track choices are important to make the system watertight and airtight along with allowing drainage to flow away from the doors. Frames should be designed to ensure a barrier between the outside and inner frame to alleviate condensation between glazed panels. There are special marine coatings for external aluminium frames to protect against harsh saline environments, this is usually recommended for coastal properties to help prevent quick corrosion of frames and components.

Once you’ve chosen your frame, track options and configuration you’ll want to look into glazing options. Standard systems will usually incorporate double glazing filled with gas (argon gas is typical) in the cavity this helps to reduce heat loss in double glazing by slowing down convection inside the air space. It is extremely cost-efficient, and works well with low-e coated glazing. Triple glazing will work in the same way, however, by adding an extra layer, heat loss is lowered even further and can help achieve lower U-values as a result. Depending on your requirements you might also be interested in either solar, tinted or laminated security glazing. Tinted glass will usually be used as a privacy measure and solar glass will also help with heat transfer by protecting against the sun’s rays and the heat being reflected from the inside.

Your home’s security is another key consideration. Make sure that the door locks you choose meet with insurance company approval and that you consider not only making it difficult for intruders to enter the property but also how they exist. Burglars often have a planned escape route in case they become interrupted, shoot bolt locking on folding sliding doors will help disable easy opening from the inside and hinder escape. Laminated security glazing will also help against break-ins for any glass door system.

You'll also want to make sure you find a quality supplier rather than a cowboy, but how do you tell the difference? Recommendations are always a good way to go. In fact a large proportion of our own business does in fact come from recommendations from past customers. I’d always look to the internet for unbiased reviews along with a company’s own testimonials. Look at the company’s track record, the longevity of the business is a good tell as to its overall success. Most importantly listen to your contractor for their personal experience and for their advice on who to use and also on which professional bodies the supplier should be a member of. A reputable supplier will always be happy for you to contact past customers (as long as the customer agrees) for first-hand experience to give you more confidence in your choice.

Sliding doors for larger glazed panel widths

So what types of external glass doors are available? Folding sliding doors will offer the ultimate wow factor to any property. They ooze quality and are designed especially to open up areas with no interrupted view. This makes them perfect for the summer months when accessing outside spaces and enhancing the light into a property when the doors are closed all year round. Sliding doors are another option. Sliding doors allow for larger panes of glass and are used when full opening isn't required. Both these systems are framed to comply to building regulations whereby main external doors require structural stability and energy ratings, however, there is an alternative for when making use of external areas throughout the year when these concerns aren't an issue. Sliding stacking doors are perfect for covered patio/decking areas and balconies to protect against wind and rain but without the thermal benefits.

Finally, what about installation of the actual product? Simply, it’s best to leave this to the professionals. Either your supplier will offer this service or your building contractor will be able to arrange this.