We have collected together a list of questions that people frequently ask us. Please check through the FAQ list here to see if we have already answered your query.

The Petflap needs to be fitted into a flat area a little bigger than 295mm diameter (or 295x295mm square for a square-edge Petflap).

The trunking needs a hole cut 256mm diameter.

Most panels, moulding, ridges or other surface interruptions, front or back of the door, preclude fitting a Petflap. Tongue-and-groove is an exception as long as all grooves are well sealed. The Petflap’s front frame needs to make a good connection to the surface, which can be hard on a door with detailing. You could fit the Petflap into a separate panel and then replace a section of your door with that panel. Otherwise your Petflap could go into glass or through a wall.

Please get in touch if you’re unsure whether your door is suitable.

Before buying a Petflap, please check:

  • Your door has a large enough flat surface to fit it into
  • Your door doesn’t have any locking or structural mechanisms inside it that will be disturbed by fitting a Petflap
  • You won’t invalidate a door guarantee by fitting a Petflap
  • Your pet can pass through comfortably (download the lifesize pdf)
  • Fitting instructions

Please ask us any questions you have about buying, fitting or using a Petflap.

Yes. For full details please see our Passivhaus page.

Can the Petflap be used with ICF construction?

Yes, for an extra fee we can supply a slightly oversized sacrificial tunnel with interior strengthening formers made of accoya. Fit this in advance of your concrete pour. When that has cured you can remove it and easily fit your Petflap in its place.

How does the Petflap compare to other top-hung energy efficent catflaps?

Passivhaus consultant Richard Bendy writes:

1/ In the context of the overall heat loss of even a small building, the U value difference between a top-hung ‘extreme weather’ catflap and The Petflap would be of little consequence as they are such small areas. However, to make a valid comparison you have to work out the heat loss from each door by multiplying its area by its U value at a given temperature difference between inside and outside.

 As one can see the Petflap has a better heat loss performance than the top-hung door in spite of its having a slightly worse headline U value.


2/ U values are only part of the heat losses for a building. Just as important, if not more so, in an ultra-low energy building such as a Passivhaus is airtightness, and whilst there is testing data to show that the PetFlap loses 1 litre of air per second when subjected to an airflow of 50 Pascals (which is extremely good – see our passivhaus page for further details) we have been unable to find any similar data available for the top-hung door to make a comparison.

A potential (but not proven) weak-point from an airtightness point of view on the top-hung door could be the frame/door junction fixing and the frame fixing to the door. The Petflap exterior door by contrast is bonded to the tunnel at the factory to ensure complete airtightness around the seal as is the inset door at the house end.

3/ From an occupant comfort point of view when the top-hung door opens a significant amount of cold air will enter; with the Petflap both inner and outer door are unlikely to be open at the same time thus minimising discomfort to the building’s occupants when your cat enters or exits.   

4/ In our experience most animals (especially cats) like to look through their door to gauge any potential danger outside before beginning their exit; this is of course hampered with the top-hung door due to the opaque insulation layer.

Even with the original U value which applies to the standard door with 70mm trunking, things aren’t bad either. When you work out the actual heat loss there’s an 85% difference which is significantly better than the 338% difference if you just compared headline U values so once again in my opinion the Petflap is still better when 2,3 & 4 above are taken into account.

Richard can be contacted as follows:

richard@thehealthyhome.co.uk +447990571394.

Please contact us  with as accurate a wall measurement as you can take, your colour choice (black, white or silver or a mix of all three, but please note we can’t provide silver trunking), and your full name and address. We will then get back to you with any queries.

We will invoice you directly, for payment by PayPal or bank transfer as you prefer. Special orders take up to two weeks from payment to despatch in most circumstances.

We can provide a regular Maxflap or one with extended trunking and a flap at each end.

Please contact us  with as accurate a wall measurement as you can take and your full name and address with mobile number for the Parcelforce consignment. We will then get back to you with any queries.

We will invoice you directly, for payment by PayPal or bank transfer as you prefer. Maxflaps take up to three weeks in most circumstances.

We are keeping plastic in the product only where we have no other sustainable solution at present. We have replaced a large section of acrylic with tricoya, a form of sustainable wood that will not require chemical sealants, fungicides, insecticides or stabilizers.

Essentially it is a wood pickled using a vinegar and it will last for at least 50 years, even 25 years under ground or water (not salt water).

Yes, with extreme care!

The surfaces on the Petflap are built from the same plastics many cars use on external surfaces. This means it takes acrylic spray paint very well. The outer faces can be sprayed any colour scheme to suit your door, your pet, your vibe! Please check the fitting instructions on how to paint it.

You will be pleased to know that painting won’t stop the Petflap being recycled. It’s been recycled once and can be recycled again. Acrylic paint is recyclable, so do the planet a favour and use that.

We don’t advertise a phone number as staff are moving around on site and there is often no-one in the office. It’s annoying hanging on the phone while it rings out, so instead please drop us an email at info@thepetflap.com with your phone number and an outline of your query and we’ll be very happy to ring you back.