Refuse Chutes and Bin Rooms in Apartment Buildings: The No. 1 Starting Point for Rat and Cockroach Infestations This Autumn

When a building calls us about rats, the request is almost always phrased the same way: "There's a rat in the cellar of Block B, we need some bait put down." When it's about cockroaches, it's: "The two-bedroom flat on the second floor is infested, that apartment needs treating."

In both cases, the request describes a symptom, not the cause. And in the vast majority of the shared-building cases we handle in the Paris region, the cause comes down to a single location, often less than twenty metres from the flat making the complaint: the bin room, or whatever is left of the refuse chute shaft.

It's a blind spot. Nobody goes there willingly, nobody inspects it, and it belongs to no particular occupant — so it belongs to no one. And that is precisely why it concentrates, all on its own, most of the resources a brown rat or a German cockroach needs to establish a lasting population in a building.

Bare mattress on a bed with a white padded headboard in a bright bedroom with a beige wardrobe

Why the bin room is the best habitat in the building

Three resources gathered in one place

A commensal pest needs only three things: food, water and shelter away from light and disturbance. A standard Paris-region bin room ticks all three boxes with formidable efficiency.

• Food: several dozen kilos of organic waste renewed daily, often in flimsy bags left beside the containers when those are overflowing.
• Water: a floor drain, a water supply for cleaning, condensation on the walls, fermentation liquid pooling at the bottom of the bins.
• Shelter: blind corners behind the containers, open service ducts, unsealed pipe penetrations, a door that hasn't closed properly since 2019.

An adult brown rat (Rattus norvegicus) eats roughly 25 to 30 g of food per day. A room generating 40 kg of waste daily could therefore, in theory, support a population of several hundred individuals. In practice, the limiting factor is never food: it's territory.

Temperature, the other forgotten variable

German cockroaches (Blattella germanica) develop optimally at around 30 °C. A closed basement bin room, warmed by fermenting waste and flanked by domestic hot water risers, reaches and maintains that temperature all year round, including in January. This explains an observation that baffles many residents' committees: a cockroach infestation in a shared building has no season. It advances continuously, at a rate of one full generation every eight to ten weeks under these conditions.

The cycle is short: a female produces on average four to eight oothecae in her lifetime, each containing 30 to 40 eggs. Without intervention, a dozen individuals in a bin room become several thousand within a season, and the colonisation of flats via the service ducts is simply mechanical.

The refuse chute: a 20th-century fixture turned public health problem

Why most were sealed off — and why that solved nothing

Refuse chutes were installed on a massive scale in buildings constructed between 1950 and 1975. Since the 2000s, the spread of recycling made them incompatible with waste collection requirements, and the great majority of buildings voted to seal them off.

The problem lies in how that sealing was done. In the best case, each landing hatch is bricked up and the shaft fully cleaned out, then closed at both top and bottom. In the most common case — and we come across several a month — the hatches were simply screwed shut or covered with a panel, and the shaft was left as it was, with several decades of residue caked to its walls.

A disused but uncleaned refuse chute shaft means:

• a vertical motorway linking the basement to the top floor, with no obstacle and no light;
• a store of fossilised organic matter feeding cockroaches, flies and booklice;
• a direct link between the sewer network (where the base of the shaft opens into the bin room, itself connected to the sewers) and the landings.

A rat climbs a rough vertical shaft without the slightest difficulty. We have documented rats reaching the 7th floor by this route alone.

How to know whether your shaft is genuinely neutralised

Three simple checks, within reach of any residents' committee member:

1. Look at the base of the shaft in the basement: is it sealed with solid masonry, or just with a rattling metal hatch?
2. Check the landing hatches: a plasterboard sheet or a screwed-on panel is not an airtight seal. A sliver of light or a draught of cold air in summer signals an open shaft.
3. Ask the managing agent for the shaft-cleaning report. If none exists, the shaft has never been cleaned.

A simple handheld draught detector or a powerful focused-beam torch is enough to carry out this diagnosis across an entire building in an hour.

What the regulations say, and where responsibility lies

The Departmental Health Regulations, the reference text

In the absence of a unified national health code on this point, it is the Règlements Sanitaires Départementaux (RSD — Departmental Health Regulations) that apply. Their Article 119 (and Articles 121 to 124, depending on the department) requires owners, managing agents and building managers to take all measures to prevent the entry and proliferation of rodents and insects, and to have rodent and insect control operations carried out as often as necessary.

In practical terms, this means that:

• the upkeep and hygiene of the bin room fall under the common parts, and therefore under the managing agent appointed by the co-ownership;
• a co-owner or tenant may formally put the managing agent on notice to act by registered letter, then refer the matter to the Service Communal d'Hygiène et de Santé (SCHS — municipal hygiene and health service) at their town hall, or to the ARS in municipalities without one;
• the mayor holds special policing powers in matters of public health (Articles L. 1311-1 et seq. of the French Public Health Code) and may order works to be carried out ex officio.

On the private housing side, the law of 6 July 1989 requires the landlord to provide decent accommodation, and the decree of 30 January 2002, as amended, specifies that the dwelling must be free from infestation by pests and parasites — a point reinforced by the law of 27 June 2024 on combating bed bugs, which clarified how costs are allocated when the infestation predates the tenant moving in.

In practice, the dividing line is simple: if the source is in the common parts, the co-ownership pays. If the source is in an occupant's home, the occupant or their landlord pays. The whole difficulty of a shared-building case lies in establishing where the real source is — and that is precisely the role of a preliminary diagnosis.

Grey and white rat nibbling a grain of corn on white fabric, close-up

Diagnosis before treatment: five signs to look for

Before any bait or spraying, a serious professional spends an hour or two reading the building. Here is what they look at, and what you can observe yourself.

One point we systematically remind residents' committees of: dry, grey droppings prove nothing about the present. They may be two years old. A simple chalk mark, or a fine layer of technical flour laid down in the evening across a suspected route and read the next morning, is worth more than three meetings of debate. To establish night-time activity objectively and without hassle, a motion-detection surveillance camera with night vision installed in the room for a week settles the question once and for all, and its cost is trivial next to that of a poorly targeted treatment.

The genuinely effective action plan, in order

1. Make the resource inaccessible

This is the step everyone wants to skip, and without which nothing holds. No bait can compete with a split rubbish bag.

• Bins always closed, in sufficient numbers to absorb the volume between two collections. A bin that overflows twice a week is a missing bin, not a lack of civic spirit.
• A strict ban on leaving bags on the floor: this single habit feeds 80% of the population.
• Cleaning the room with water and detergent at least once a week, with drainage through a working floor drain. A room hosed down without drainage creates a permanent puddle, and therefore a water source.
• Recycling bins fitted with lids on intact hinges; a broken lid gets replaced, not endlessly "reported" at the general meeting.

2. Close the routes

This is the heart of lasting work, and it belongs more to masonry than to chemistry.

• Sealing pipe penetrations with mortar packed with stainless steel wool or fine mesh — expanding foam on its own is gnawed through in a single night.
• Fitting a brush door sweep or metal seal to the room's door: a rat gets through a 12 mm gap, a mouse through 6 mm.
• Ventilation grilles replaced with stainless steel mesh cloth of 5 mm maximum aperture.
• Floor drains fitted with non-return valves where they connect to the sewer network — the most underestimated entry point in dense urban areas.

A roll of fine-mesh stainless steel netting and a cartridge of mortar sealant are enough to deal with most of the weak points in a standard bin room, provided you devote a proper half-day to it rather than ten minutes.

3. Treat, and only then

Once the first two steps are under way, chemical control becomes effective because the bait once again becomes the most attractive resource in the room.

• Rodents: secured, locked bait stations fixed to the floor, with a numbered layout plan and an inspection log. The use of second-generation anticoagulants is governed by European biocide regulations and by the opinions of ANSES, which regularly points out the risks of secondary poisoning for non-target wildlife and pets. Loose bait dropped in a corner is both ineffective and dangerous.
• Cockroaches: insecticide gel in micro-deposits, never blanket spraying, which scatters the population into the flats. A plan of numbered monitoring sticky traps makes it possible to measure the decline objectively between two visits, something plain observation can never do.
• Two to three visits at least three weeks apart, to cover the development cycle.

Small brown mouse with large ears moving across a concrete floor in dim light

What a co-owner can do starting tomorrow

You're neither the managing agent nor a member of the residents' committee, and you're seeing rats or cockroaches in the common areas? Three useful actions, in this order.

1. Document. Dated photos, videos, a record of dates and places. A factual file completely changes the tone of a general meeting. Keep everything in a single written thread.
2. Write to the managing agent by registered letter, explicitly citing Article 119 of your department's RSD and requesting: a professional diagnosis of the common parts, a quote for cleaning out and sealing the refuse chute shaft, and the setting up of an annual rodent control contract with a log available for inspection.
3. Refer the matter to your town hall's SCHS if there is no response within a month. In Paris, this is the Service Parisien de Santé Environnementale; in the inner suburbs, the municipality's hygiene department. Their findings carry real weight.

Meanwhile, inside your own flat, the measures that limit colonisation from the common areas are inexpensive:

• sealing pipe penetrations under the sink and behind the toilet;
• a draught excluder or seal on the flat's entrance door, especially if you are the closest dwelling to the refuse chute room;
• food stored in airtight storage containers rather than open packets, which removes the resource for any cockroaches that have already crossed the threshold;
• a kitchen bin with a lid, emptied daily while the building is infested.

The false economy of treating "flat by flat"

We'll finish with the point that costs co-ownerships the most: treating the flats that complain, one by one, without ever touching the common parts.

This pattern always produces the same result. The treated flat sees its population drop for six to eight weeks, then is recolonised from the service duct. The untreated neighbour acts as a reservoir. After two years, the co-ownership has spent more on one-off interventions than a comprehensive plan would have cost, and the infestation has spread.

Cockroach treatment in a shared residential building only makes sense if it covers, within the same time window, the common parts, the ducts and all the flats on the affected riser or risers. It's demanding to organise — you need access, and therefore communication with residents — but it is the only set-up that produces eradication rather than perpetual management.

The bin room is not a housekeeping detail. In a shared residential building, it is the organ that determines the health of the entire property. Putting it back in order generally costs less than a single year of scattered treatments — and it is the only investment whose effect lasts beyond the season.