Bed bugs in flats and shared buildings: why one flat is never the whole story

The short answerIn a block of flats or a converted house, bed bugs move between homes through service voids, cable runs, floor gaps and shared corridors, so treating one flat alone usually fails within weeks. The landlord, managing agent or housing provider is the only party who can inspect the neighbours and coordinate a block treatment. Report it to them in writing on day one and ask what they will do about the flats either side.

Ask any experienced technician about the jobs that come back, and they will tell you about flats. A bedroom is treated properly, the guarantee passes, and three months later the bugs are back. Not because the treatment failed, but because it was never the whole problem. The flat next door was never looked at.

This post explains how bed bugs move through shared buildings, who can do something about it, and what to ask for.

How bed bugs move between flats

Bed bugs do not fly or jump. They walk, and they are good at it. In a purpose-built block they follow the routes that already exist between homes:

• Service risers and pipe boxing, where heating and water pipes pass between floors.
• Cable runs and the gaps behind sockets on party walls.
• The space under skirting boards and between floorboards and the ceiling below.
• Door thresholds onto a shared corridor, especially where carpets meet.
• Shared laundry rooms, bin stores and lifts, via bags and furniture.

In a converted Victorian or Edwardian house, the routes are more generous still. Floor voids run the width of the building. Chimney breasts are shared. Firms on the London page and the Bristol page deal with these conversions every week, and the first thing a good one asks is who lives either side.

There is a second route that has nothing to do with the building. When a flat is treated and the occupier panics, bedding and furniture get moved into the corridor or a friend’s flat. The bugs go with them.

Why treating one flat fails

A spray course leaves a residue that kills bugs walking across treated surfaces, but it does not seal the wall. A heat treatment kills everything in the flat on the day and leaves nothing behind at all. Either way, a bug that walks in from next door a fortnight later finds an empty flat with a sleeping host. Our heat treatment page covers this failure mode in more detail.

The guarantee usually will not help. Most firms exclude reinfestation from an untreated neighbouring property, and they are right to.

So the question is never “which treatment” on its own. It is “which flats”.

Who coordinates

Here is the practical problem. You can only authorise treatment of your own home. You cannot make the neighbour let a technician in, and you cannot inspect the void between you. Only one party in a building can do that, and it is the party responsible for the building.

Private block with a managing agent. The agent, acting for the freeholder or the residents’ management company, can write to all flats, arrange inspections and commission a block treatment where it is needed. Cost allocation is a matter for the lease, but the coordination is theirs to do.

Council or housing association block. The landlord’s repairs or estate team coordinates. Southwark’s review of pest control for council tenants, published by the council, sets out the logic: in multi-occupied buildings the landlord treats adjoining dwellings as part of the same job. Many large social landlords have a pest contract that does this routinely.

Converted house with one landlord. The landlord commissions one firm for the whole house. This is the simplest case and the one most often done badly, because the landlord treats only the room that complained.

Converted house with several leaseholders. The hardest case. There may be no agent and no single owner. The one with the bugs usually ends up doing the chasing. Put it in writing to everyone and keep copies.

Shelter England and Shelter Scotland both set out when the landlord is responsible. Our guide to bed bugs when you rent covers each part of the UK, including deposits.

HMOs

A house in multiple occupation, where three or more people from different households share, is a special case. GOV.UK explains when an HMO needs a licence in England. Licence conditions and management regulations put the common parts, and usually the whole house, on the landlord or manager. In Scotland and Northern Ireland the licensing regimes are stricter.

In an HMO, treating one bedroom while the one next door is untreated is wasted money. Student lets in Leeds, Sheffield, Manchester and Newcastle are the classic example: five bedrooms, thin stud walls, and a landlord who wants to pay for one room. Insist on a whole-house inspection and quote.

What a block treatment looks like

A firm engaged by the landlord or agent will typically:

1. Inspect the reporting flat and every flat that shares a wall, floor or ceiling with it.
2. Inspect further out if any of those show signs.
3. Treat every affected flat in the same week, so bugs have nowhere to retreat to.
4. Treat or monitor the unaffected neighbours, with interceptor traps or a light residual spray at entry points.
5. Return for follow-ups on the same schedule across all flats.
6. Issue one written report covering the building, with a plan.

Detection dogs earn their fee here. Checking twelve flats visually takes days; a dog and handler can screen a floor in an hour.

What to ask the managing agent or landlord

Send these in writing on the day you report:

• Which flats adjoin mine, and will they be inspected?
• Who is commissioning the treatment, and which firm?
• Is the firm on the BPCA or NPTA register?
• Will all affected flats be treated in the same week?
• Will I receive the report?
• What is the plan if a neighbour refuses access?

That last question matters. Landlords have rights of access with notice, and councils have powers under housing law to require action on pest hazards. An agent who shrugs at a refusing neighbour has not tried.

While you wait

Keep sleeping in your flat, and do not move belongings into the corridor or a friend’s home. Prepare as described in our guide to what happens during treatment, bag and hot-wash the bedding, and note every bug you see with the date.

If the landlord or agent is slow, you can still arrange your own inspection to get written evidence of the extent. Choose a registered firm that covers your area: see how we check. Firms used to blocks are on the Glasgow page, where tenements are the norm, the Edinburgh page, the Birmingham page and the Liverpool list. Everywhere else is in the A to Z of towns. You contact them directly; we never sell your details.

One flat is never the whole story. The sooner the building is treated as the unit, the sooner it is over.