Energy efficient self builds

Self-build homes are often built to high standards of energy efficiency. Usually this includes very thick walls. We are often asked if we can provide Petflaps with trunking suitable for this type of build: the simple answer is yes.

When you’re planning a new house it’s simplest to work the fitting into the build from the outset.

We can supply sacrificial trunking to place hold during a concrete pour or other construction process.

For existing houses too

Of course it’s not only self build homes that want to fit a Petflap into a thick wall. We can supply a Petflap to go into an extension or renovation, or an existing wall.

A double-ended Petflap with extended trunking

Extended trunking through a thick wall

Our standard trunking is 70mm long and suitable for most ordinary doors and windows, including double-glazed units. As long as a minimum of 5mm of trunking extends beyond the door or glass then the fitting ring can be fixed on and all is well.

A Petflap going into a brick or stone wall needs to have trunking long enough to line the whole thickness of the wall, plus 1cm. We recommend this for several reasons:

  • the hole through the wall is sealed by the trunking, so bits don’t come away which would compromise the hole and create a mess
  • the wall is supported by the light but robust trunking
  • the longer models need a second flap at the other end

How long can trunking be?

At the moment, we can do up to 590mm. 300-400mm is the most common range we’re asked for.

We can also do just very slight increases. We’ve provided Petflaps with trunking of just 80mm. We can also do shorter trunking from 35mm.

Double-ended Petflaps

For trunking of about 240mm or longer we fit a Petflap at both ends. We do this for several reasons:

  • there is a lock on the outside, making locking much simpler than reaching to the far end of the tunnel
  • it creates a neat finish at the house end of your Petflap
  • the Petflap and the hole through the wall are supported properly at each end under equal force

The double flap arrangement increases the Petflap’s insulating properties. There will be twice the 14mm thickness and a baffle to cold air sneaking in alongside your pets.

Fitting two flaps doesn’t increase the Petflap’s draughtproof properties as a single door is enough to do that.

My architect has questions

No problem. We’re very happy to speak to architects, builders, interior designers, glaziers, fitters and so on. Please give us their number or ask them to get in touch at

Dimensions and fitting information can be found on this site at Fitting a Petflap and Measuring for a Petflap.