The Paths Between the Annexe and the House
Think about what travels between the two buildings in a normal week. Washing is the obvious one: bedding and clothes from the annexe often go to the machine in the house and sit in a basket on the way. Then there are grandchildren who nap on the annexe sofa, a relative who comes over every evening, and bags, coats and shopping going back and forth.
None of that is a reason to lock the annexe up. It is a reason to change a few habits until it is treated. For a few weeks, the garden path should carry as little fabric as possible, and whatever does cross it should be bagged or freshly washed.
- Bag annexe laundry before it leaves the annexe and put it straight in a hot wash.
- Keep coats and bags from the annexe off the beds and sofas in the house.
- Ask whoever lives in the annexe to keep sleeping there, not in the house.
- Check the beds in the main house anyway, especially any the annexe resident uses.

Treating Only the Annexe
If the house is clear, a Pinner annexe can usually be treated on its own. That is simpler than treating a bedroom inside the house, because there is no landing or shared wall for bedbugs to follow. An inspection of both buildings, from £120, tells you whether that is the right call before you pay for treatment.
When you ring, tell us how the annexe is built and how it is heated. Timber-framed garden buildings, older conversions of garages and brick extensions all behave a little differently, and that shapes how we plan the job.
Heat or Chemical for an Annexe in Pinner
A small annexe with one bedroom and a living area often suits heat treatment: one visit, eggs included, with the whole space done in a day. Whoever lives there spends that day in the main house, which is easy to arrange when family is a few steps away. Heat costs more than chemical.
Chemical treatment works well when the problem is limited to the bed. It usually takes two, sometimes three, visits, and the annexe resident has to strip the bed and clear the floor each time, which may need a hand if they are older. Treatments start from £220, and we give you the figure on the phone before booking.
When the Annexe Is Let
If the annexe is rented to a tenant rather than used by family, who arranges and pays depends on the tenancy and on how the bedbugs got in. Put things in writing, and get advice if there is a dispute; we are not legal advisers. For households in Pinner where a relative has just moved in, the Stanmore page looks at checking their belongings, and the Harrow page covers changing households.
Bedbug Control Pinner — Questions
Do you need to treat the main house as well?
Only if there are signs there. We check the beds and sofas that the annexe resident uses in the house before we decide.
Can the person in the annexe sleep in the house until it is treated?
We advise against it. Moving to another bed is one of the most common ways bedbugs reach a new room.
Is a garden annexe harder to treat than a bedroom?
Not usually. It is often easier, because it is self-contained. Tell us how it is built so we can plan properly.
Should we wash everything from the annexe?
Wash the bedding and the clothes that have been in the bedroom. There is no need to empty every cupboard in Pinner if they show no signs.
What if the annexe has no washing machine?
Bag the laundry inside the annexe, tie it, and carry it straight to the machine in the house. Put the empty bag in an outside bin.
Elsewhere in Harrow
The other areas in the borough, each written around a different situation.
Bedbug Advice for Pinner
Picked for this page: the guides that go further on what matters for Pinner.

What Happens During an Inspection
From your side of it: how long, whether you stay, what we will ask and what we will move.
Read more →
How Heat Treatment Works, and Does It Kill Eggs?
What heat actually does to a bedbug, and why an egg has no defence against it.
Read more →
Do Bedbugs Live on People?
Why bedbugs feed and walk away, why they are not in your hair, and why scrubbing yourself does not help.
Read more →
Are Bedbugs Caused by Damp?
The damp myth, the insects that really do like it, and why a spotless house is not protected.
Read more →Bedbug Treatments in Harrow
Every service has its own page for Harrow: heat, chemical, hotels, commercial premises and inspections.
Covering Pinner
Tell Us About the Property
Tell us what the annexe is used for, how many rooms it has and who uses the main house as well.