Installing Dog & Cat Flaps In Double Glazing Glass and UPVC Patio Doors

There is no greater joy than seeing your pet strut around happily at the peak of comfort. A prime way to ensure your pet is comfortable and free is to install cat or dog flaps into your doors. It applies even to double glazed or UPVC patio doors- you have an assortment of options at your fingertips.

For canine or feline lovers, a high and waggy tail or a string of purrs is the greatest reward! These signs indicate your dog or cat is happy. Convenience and freedom play a vital role in their contentment.

Since you have a double glazing glass and UPVC patio door, selecting an appropriate pet flap is tricky. You also need to consider several factors before adding a dog or cat flap to these distinct doors.

Read on to gain insight into installing dog and cat approachability flaps in double glazing glass and UPVC patio doors.

Factors to Keep in Mind Before Installing A Flap for Pets

If your home already sports a double glazing glass patio door, the best path to take is to approach a double glazing company. Start a conversation about installing a dog or cat flap, and they will be able to support you suitably. You can also seek advice on appropriate types of flaps for your pet, environment, and door.

While it is exciting to engage in DIY installation- and the internet is rife with such solutions- it is not advisable. If you decide to take it upon yourself to install an accessible pet flap, you may end up spending more instead of saving.

To ensure a clean and safe installation, hire a professional. Even a slight misstep can cause the glass to mist and expose your home to the entrance of air.

Are you preparing for the installation of a new double glazing glass door? If that is the case, then you must pre-order a fitting pet flap with the door. It is the most convenient and practical way to get your job done. Contact your door company and discuss all available options. They will be able to provide the best advice and often go ahead with the installation as well.

Now that you are aware of these precautionary pointers- read on some critical aspects that you cannot overlook when installing a flap.

Size of The Dog or Cat Flap

The first step towards mounting a cat or dog flap on your dual glazing glass window or door is to determine the size you will need. Remember, it is a colossal hassle and additional risk to redo the process of installing pet flaps into these doors.

To avoid damage or extra costs, meticulously measure your pet. Try to do it in a way that will allow them to walk through the flap at any stage of their growth.

How to Measure Your Pet for A Dog or Cat Flap?

You need to measure the height of your pet first. If you have a younger pet, determine the maximum height your poppet will gain after reaching adulthood.

To obtain accurate measurements of your canine or feline buddy, make sure they are standing straight. Seek the tallest portion on your pet’s back- generally between the shoulder blades. From this point, measure their height down to the ground.

The height of the pet flap should always be an inch taller than your fuzzy companion. It is to safeguard them from injuries if they tend to barge in and out like a rascal.

The next step involves determining the width of the flap you will need. You can either measure your pet from shoulder to shoulder or block a doorway and observe the minimum space for passage.

As is the case with height, the pet flap’s width should also be an inch greater than your pet.

Once you have all the measurements, create a trial pet flap, and check if your pet can pass through comfortably.

The Stepover

You must also consider the distance between the flap and the floor- known as the “stepover.” It should be as low as possible so that your furry friend can move comfortably. Younger and older pets may find it challenging to overcome a high stepover.

Ideally, the stepover’s height should not be more than 1/3rd of the total height of your companion. Even so, you must mount the flap a minimum of 3 inches above the floor. It is to preserve the integrity of your door.

Security of The Dog or Cat Flap

Security is paramount when it comes to installing dog or cat flaps in double glazing and UPVC patio doors. A large flap exposes your home to the risks of a burglar or wild animal entering through it.

While a standard, manual pet flap does not offer much security, you can opt for a more advanced model. Such models include magnetic pet flaps and automatic ones with microchips.

The latter is the most secure since they give access only to your pet via chip detection. However, these can sometimes fail, and your pet may get stuck outdoors or indoors.

Aesthetic Appeal and Pattern

Part of the charm of glazed glass and UPVC patio doors comes from their subtle and appealing look. When you plan on adding pet flaps in these doors, you must take the colors and materials into account. They should perfectly complement your patio doorway instead of compromising on the appeal!

Types of Cat and Dog Flaps Available for Double Glazing Glass and UPVC Patio Doors

You may feel that there are not many options for you when you need a pet accessibility flap for a double glazed glass door. It is a misconception- you can have your pick from several types of flaps for pets, with varying degrees of security. Take a look at the options below.

Classic Pet Flaps

A classic pet flap is the most common type of dog and cat door that people use. In essence, it is a manual, fundamental flap on a spring. It is the most inexpensive option for your dual glazing glass and UPVC door.

While they are convenient, they come with numerous disadvantages as well. Your home runs the risk of wild animals or other pets entering it.

They also do not shield your spaces from external elements like poor weather. Classic pet flaps may also prove to be a chink in the armor of your home’s security from trespassers.

Lockable Dog and Cat Entrance Flaps

As you can infer from the name, lockable dog and cat gateways come with a bolting system. They offer more control. Most of these flaps also feature a security barrier to protect your home from uninvited animals and unpleasant weather. Lockable pet flaps also fall in an affordable range.

Infrared Pet Flap

While infrared pet flaps are certainly more expensive, they provide full value for their cost. They allow you to be in charge of who passes through the flap.

It is with the help of an infrared key with a matching one on your pet. These infrared keys feature a color code that denotes the frequency it uses. You can buy more than one infrared key. Infrared pet flaps are more secure than other general types.

Magnetic Dog and Cat Flaps

Magnetic pet flaps fall second in line when it comes to security, using a unique tag or collar. Keep in mind that such a flap in your glazed glass door may take a while to recognize your furry friend. It hinders their ability to enter freely and instantly.

Microchip Flaps

Microchip pet flaps are the most expensive type for your reinforced, glazed glass and UPVC patio door. Despite this, they provide the highest level of security, along with unchecked freedom of movement to your pet.

These flaps function through electronic tags or microchips that you will need to place on your pet’s collar or under their skin. Each microchip has a unique configuration of your canine or feline friend.

The Best Dog and Cat Flaps for Double Glazed Patio Doors: Top Recommendations

The sections above outline the prerequisites for installing a feline or canine flap into your twin glazed glass and UPVC patio door. With that in mind, take a look at some of the best options.

PetSafe Staywell, Convenient, Original 2 Way Pet Door, Fast Installation, Easy Fitting, 2 Way Locking, Cat Flap for All Pets – Medium - White
If you seek a classic, reliable pet flap, this PetSafe Staywell Pet Flap is a suitable candidate. It allows quick and convenient installation and features a quad-way locking mechanism. You can configure it to four settings: In, Out, Open, and Closed.

You can buy it in a frosted and white finish- it will be an unobtrusive addition to your double glazing glass and UPVC patio door. The PetSafe flap is flexible and weatherproof, with insulation. It is an unrivaled option if you are working with a relatively low budget.


  • Affordable
  • Flexible plastic construction
  • Integrated draft excluder
  • Adjustable system of locking
  • Simple to install


  • Circular profile may not suit all conditions
MILO & MISTY 2 Way Locking Dog Flap Pet Door - White, Medium
The Milo & Misty 2-Way Locking Dog Flap is a magnetic pet flap available in subtle white color to go well with your twin glazed glass door. It is appropriate for both- interior as well as exterior doors of any thickness.

This particular flap is excellent for cats and medium dogs with a height of up to 460 mm. It is a well-qualified option with brush seal protection against harsh weather conditions and draught. The flap has a robust construction, and you do not have to worry about damage if your furry friend is feisty.


  • Comes with a removable plastic locking panel for security when not in use
  • Lightweight and practical
  • Inexpensive
  • Suitable for medium dogs as well
  • Features optional extension tunnels


  • May be too large for cats.
  • Offers lesser protection as opposed to microchip pet flaps
  • It May not offer precise fittings.
Cat Mate Elite Microchip Cat Flap with Digital Timer & LCD Display for up to 9 Cats, White
1,073 Customer Reviews
Cat Mate Elite Microchip Cat Flap with Digital Timer & LCD Display for up to 9 Cats, White
The Cat Mate Elite Microchip Cat Flap is a pleasing solution for selective entrance. It is suitable for cats and small dogs. It runs on the unique microchip on your pet, eliminating concerns of uninvited or intrusive visitors!

You can register up to nine cats with the flap, with the LCD panel displaying detailed information for any three cats of your choice. The Cat Mate Elite Microchip Cat Flap features a four-way system of locking and a magnetic closing.

The flap is brush-sealed and weatherproof. The flap allows you to set limits upon the accessibility of the doorway. It is self-lining to 100 mm thick- it makes the pet flap an ideal candidate for your double-layered glass and UPVC patio door.


  • Features a timer
  • Provides helpful information about your pet’s location
  • Durable polymer construction
  • Offers 3-year warranty


  • Requires you to make a new panel for installation into twin glazed glass and UPVC patio doors
  • May be noisy
  • Prone to electronic malfunctions
PetSafe Sliding Glass Cat and Dog Door Insert - Great for Rentals and Apartments - No Cutting DIY Installation - (Medium)
Whether you are looking for a permanent or a temporary fix, the PetSafe Sliding Glass Pet Door fits each profile. It is a fitting choice for your door, no matter what size your furry friend is. With sturdy double-piece aluminum construction, its design enables you to incorporate it into any double glazing glass door.

It also features a 4 mm protection glass to reinforce in terms of safety and strength. A magnetic vinyl lock mechanism gives you control when you need to keep your pet inside or outside. Its temporary installation provision makes it possible for you to use it if you are renting.


  • All-size does not require cutting or drilling.
  • Automatically fine-tunes to doors 194-205 cm high.
  • Comes with an option for temporary installation
  • Robust, snowy aluminum frame


  • Expensive
  • Installation may present itself as a hassle due to 2-pieces.
SureFlap Cat Flap with Microchip Identification, White (4 x AA batteries required)
SureFlap has an array of Pet Flaps distinctly for double glazed glass doors. They come in a wide range of sizes and styles, all while being unobtrusive and preserving the look of your door. This SureFlap Cat Flap is easy to install and offers a variety of accessories too.

It is functional with all typical variants of RFID collar tags and microchips. All you need to contribute at your end are four AA batteries that will last for a whole year. This flap fits into a circular hole. The opening can have a diameter of up to 260 mm.


  • High security
  • Save up to 32 pet profiles with convenient single-button programming.
  • Available in two colors


  • Does not offer control over selective pets
  • Does not include a timer like other models
PetSafe Microchip Activated Cat Flap, Exclusive Entry, Easy Install, 4-Way Manual Locking, Energy Efficient, Draught Excluder, Convenient (New Version)
The PetSafe Microchip Activated Cat Flap offers exclusive entry for your companions. With no hassle during installation, it comes with a quad-way manual bolting system. You can program this PetSafe flap to identify a maximum of 40 pets.

It is an incredibly energy-efficient item with a breeze excluder and locking points that close magnetically. It enhances insulation. If you value flexibility, this pet flap will be of interest to you since it is highly versatile. It conveniently acclimatizes to cut out dimensions for Staywell plus Microchip Petporte flaps too.


  • Dual auto-locks and manual four-way lock
  • Energy efficient
  • Durable frame of plastic
  • Includes cutting template


  • Requires separate 4 AA batteries- however, they should be non-rechargeable
  • Reads only the most common type of microchip, FDX-B with 15 digits
SureFlap Microchip Pet Door Connect without Hub - App Controlled, White (4 x C batteries required)
With this SureFlap Microchip and App-Controlled Pet Door, you can ensure the comfort of your furry buddy with optimum convenience. You can control the flap with an app, having the ability to lock and unlock the door from a remote location.

You can set a curfew for your canine or feline mate too. It permits you to monitor and follow the activity and behavior of your pet as well.

The flap comes in a pleasant white shade, a fine pick for a double glazed glass unit. A drawback is that you need to have a SureFlap Hub to operate this pet flap, and you will have to buy it separately.

With a battery life of over six months, it requires 4 C cell batteries. It functions satisfactorily with worldwide microchips as well as RFID tags.


  • Includes one RFID collar tag
  • Cost-effective
  • Ensures optimum security
  • App-control is possible


  • Expensive
  • SuperFlap Hub is an additional expense
  • Does not include batteries

The Benefits of Installing A Flap for Your Pet

With a dog or cat flap, your furry friend will be at ease in your absence as well. Such flaps allow your pet to go where they please, without needing to seek your attention for assistance. A flap makes it possible to leave them home alone for long periods without some worries.

It will also reduce the occurrences of in-house accidents. Young or old pets without much control over their bladder may cause plenty of such accidents, so it is better to be safe than sorry!

A pet flap will free you from any nagging worries regarding the comfort of your pet. It will vastly improve the quality of life for you and your pet.

In addition to this, a pet entrance in your double glazing glass and UPVC door will spare it from constant scratching or biting. Many pets tend to engage in this behavior when they need to go out or come inside.

Pets love spending time outdoors, and it contributes to their overall physical as well as mental health. The ability to venture outside as they wish grants mental stimulation.

It boosts the health, happiness, and awareness of your dog or cat. It also helps them combat boredom, which often leads to displays of destructive behavior.

Things to Note When Hiring an Installer for Your Pet Flap

You already know that it is always better to seek a professional’s help for the installation of a flap, especially in a dually glazed glass and UPVC patio gate. These types of doors require special care and cutting-edge tools.

Here are some points you must remember when hiring an expert to install a cat plus dog flap.

  • Consult at least two different tradespersons
  • Read online reviews
  • Do not pay the full amount upfront to avoid shams or scams.
  • Acquire the quote in proper writing
  • Always ask for a receipt for all payments.
  • Since double glazing glass doors are a risk to work with, ask for a reference.

The Costs Associated with Installing Dog or Cat Flaps into Double Glazing Glass and UPVC Patio Doors

The price of installing a canine or feline flap into a double glazing glass and UPVC terrace door relies upon several aspects. You have to consider the cost of buying a pet doorway and then the service charges of hiring a professional to install it.

The size, quality, technology, brand, and construction dictate the cost of the pet flap.

Microchip and magnetic pet flaps are certainly more expensive than standard spring cat or dog flaps. The former can cost a minimum of £50 while the latter can demand as little as £10.

Many door-installation companies will install your pet flap for free if you pre-order it with your double glazing glass door. Beyond that, typically, the cost of installation depends upon the size of the pet flap. It can range from £80 to as much as £250. You will have to pay more if you must replace a glass door panel with a UPVC panel to fix the flap.

To Sum Up

Your dog or cat is your best friend- they love you with all their being! It is why the responsibility of ensuring they are comfortable and happy in their surroundings falls heavily upon you. Pets generously value their freedom of movement, and a dog or cat flap serves them with this freedom.

While it is challenging to install any pet flap in a double glazing glass plus UPVC patio unit, it is not nearly impossible. There is an assortment of super-secure options available- and they will preserve the charm of your door as well!

About Mat

A complete novice trying to navigate in the world of DIY. I bought my first home about 2 years ago & ever since I've been trying to research & learn how best to tackle common household problems.

Leave a Reply

Your email address will not be published.