HMO glossary

A council scheme in England or Wales requiring licences for HMOs outside mandatory licensing in a designated area, for up to 5 years.

Arc fault detection device: a protective device that detects dangerous electrical arcing, called for in HMOs on new socket circuits by BS 7671.

A council direction removing a permitted development right, often the change from a family house to a small HMO.

Rules setting timescales for landlords to investigate and repair damp, mould and other hazards. In force for most private tenancies in Scotland from October 2026; at consultation for private renting in England.

The service that checks building work meets the building regulations, run by councils or approved inspectors.

In Scotland, the approval needed before certain building work or changes of use.

EICR codes: C1 danger present, C2 potentially dangerous, FI further investigation needed.

The most serious level of hazard under the HHSRS, which a council must act on.

Electrical installation condition report: an inspection and test of the electrics, needed at least every 5 years for rented homes.

Lighting that comes on automatically if the mains supply fails, to light the escape route.

A private shower room with WC and basin attached to a bedroom.

Energy performance certificate, rating a home’s energy efficiency from A to G.

A fire door rated to resist fire for about 30 minutes, with smoke seals.

A review of fire risks and precautions in a building. Required for common parts under the Fire Safety Order in England and Wales, and widely used for HMOs.

Sealing gaps where pipes and cables pass through fire-resisting walls and floors.

The record of an annual gas safety check by a Gas Safe registered engineer.

A panel-based fire alarm system with a control panel, often used in larger HMOs.

A system of mains-powered detectors with battery back-up, interlinked, often used in smaller HMOs.

The Housing Health and Safety Rating System, used by councils in England and Wales to assess hazards such as fire, damp and falls.

A house in multiple occupation: a home shared by people who are not one household, sharing a kitchen, bathroom or toilet. Each UK nation defines it slightly differently.

A seal around a fire door that expands in heat to close the gap.

Housing – Fire Safety guidance (2008), used by many councils in England to set HMO fire standards. It is guidance, not law.

The register every private landlord in Scotland must join, renewed every 3 years.

Levels of detection coverage: LD1 most rooms, LD2 escape routes and higher-risk rooms, LD3 escape routes only.

A pump that grinds and pumps waste, used where gravity drainage is not possible.

National HMO licensing. In England it covers 5 or more people in 2 or more households; in Wales, HMOs of 3 or more storeys with 5 or more people.

A change of use that brings in building regulations requirements, such as fire, ventilation and energy standards.

Minimum energy efficiency standards: rented homes in England and Wales must currently reach at least EPC E.

The service at Belfast City Council that licenses HMOs for every council in Northern Ireland.

The part of the building regulations in England and Wales covering fire safety.

The part of the building regulations in England and Wales covering sound insulation.

Building work or changes of use allowed without a planning application, subject to conditions.

The stair, landing and hall that people use to get out, built to resist fire for a set time.

The registration and licensing scheme for landlords and agents in Wales.

English legislation reforming private renting, with stronger council enforcement and penalties from May 2026.

A list of works a council requires, often attached to a licence, notice or inspection letter.

A converted block of flats that does not meet the building standards set out in the Housing Act and where fewer than two-thirds of the flats are owner-occupied.

A council scheme in England or Wales requiring licences for other privately rented homes in a designated area.

A device that closes a door automatically so a fire door works when needed.

A use that does not fall into any planning use class. Large HMOs of 7 or more people are sui generis in England.

A lock that opens from inside without a key, so occupants can escape quickly.

The planning use class for dwelling houses, including families and up to 6 people living as a single household.

The planning use class for small HMOs of 3 to 6 unrelated people, in England and Wales.

A period when a room or property is empty between tenancies.