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Landlords

HMOs and Student Houses: Legionella Control for Shared Homes

Houses in multiple occupation and student lets usually carry more legionella risk than a single family home. Here is why, and what to do about it.
6 min read · Updated October 2026

Why shared houses are different

HMOs often have more bathrooms, larger hot water cylinders and sometimes cold water tanks in the loft. Rooms and en-suites can sit empty between tenancies, and student houses are often empty for most of the summer. All of this means more places for water to stagnate.

What a good HMO assessment looks at

  • Stored hot water temperature and whether the cylinder reaches 60°C
  • Any cold water tank, its lid, insulation and condition
  • Showers and en-suites that may go unused
  • Dead legs left from earlier conversions
  • Who lives there and how the house is occupied through the year

Summer voids and new tenancies

Before a new group moves in, flush every outlet, starting nearest the hot water source, descale shower heads and check temperatures. Long summer voids may need weekly flushing or a recommissioning visit. See our recommissioning guide.

Licensing and records

Councils increasingly ask HMO landlords to show they have assessed legionella risk. Keep the written assessment, a record of void flushing and the tenant information you have given out. Our landlord risk assessment includes a tenant information sheet.

Frequently asked questions

Do HMOs need legionella testing?

Not usually. As with other domestic lets, temperature control and keeping water moving are the main controls. Sampling may be recommended in unusual cases, such as large stored systems that cannot reach temperature.

Who is responsible in a managed HMO?

The landlord remains the duty holder. A letting or managing agent can carry out tasks on the landlord's behalf if this is agreed and they are competent.

Disclaimer: This guide is general information about UK requirements and is not legal advice. Always check the current legislation and guidance for your premises.