What are HMOs and why are they being vandalised?

In recent weeks, a spate of vandalism has seen up to 50 houses attacked in Salford and neighbouring areas of Greater Manchester.

Windows have been smashed, doors ripped from their hinges and walls daubed with graffiti opposing "HMOs".

The term HMO is not widely known outside housing and planning circles. It stands for "House in Multiple Occupation" and refers to properties where three or more unrelated people live, usually with separate bedrooms but shared facilities such as kitchens and bathrooms.

While HMOs are often associated with students and young professionals, they can also provide accommodation for people leaving prison, those recovering from drug or alcohol problems, and refugees.

Police in Salford have said they believe that the recent spate of vandalism aimed at HMOs in the area has been "racially or religiously motivated".

The term HMO was formalised in the Housing Act 1985. Before then, and for many years afterwards, such properties were more commonly known as bedsits or lodging houses.

In general, a HMO is a property occupied by at least three people who are not part of the same household and who share facilities such as a kitchen, bathroom or toilet. It must be their main residence.

A building made up of self-contained flats is not a HMO. Landlords have, however, unsuccessfully argued in court that rooms in HMOs were self-contained flats because they contained their own microwave.

The distinction matters because HMOs are subject to additional rules and regulations, and landlords may need a licence from the local authority to operate them.

As registration and licensing requirements have been introduced over time, it has become easier to track the number of HMOs in England.

But an exact figure is difficult to establish. By law, only larger HMOs housing more than five people must be licensed, and in some areas there is no requirement for HMOs to be registered at all.

Councils estimated there were about 450,000 HMOs in England in 2024. The English Housing Survey suggested the true figure could be closer to 800,000 because many HMOs are not licensed or registered.

The survey estimated there were about 420,000 HMOs in 2010, indicating the number may have risen by up to 90% since then.

Official records show cities, particularly those with large student populations, have the highest concentrations of HMOs because many students live in shared accommodation.

Leeds (21,000), Liverpool (16,000) and Bristol (13,000) have historically recorded the highest numbers of HMOs, according to local council estimates.

There are an estimated 5,000 HMOs in Manchester, but thousands more beyond the city council's boundaries. There are about 3,000 HMOs in the boundaries of Salford, for example.

But universities are not the only factor affecting where HMOs are found. They are often concentrated in areas where property is relatively cheap, rental yields are higher and there is strong demand for lower-cost housing.

In recent years, some local authorities have introduced new rules designed to limit the spread of HMOs in particular neighbourhoods. The rules mean landlords must seek planning permission before converting ordinary family homes into HMOs for between three and six people. In Liverpool, councillors are currently considering extending the restrictions across all neighbourhoods.

HMOs can be run by private landlords or registered social landlords. But HMOs are also increasingly marketed as investment opportunities with guaranteed returns at fixed percentage rates. Some firms offer investors the chance to invest in single rooms in HMOs, in similar ways to how single rooms in student accommodation blocks have been marketed in the past.

Parliamentary briefings have noted that part of the appeal of investing in HMOs is that some properties accommodating vulnerable groups, such as prison leavers, care leavers and people recovering from drug or alcohol problems, are exempt from normal housing benefit restrictions.

This can mean that landlords stand to receive more money from HMOs that cater for people in these categories.

Since the coronavirus pandemic, and particularly following the peak in small-boat crossings in 2022, hotels have been the main form of accommodation for asylum seekers. The government has said it is now phasing out their use.

HMOs have also been used to house asylum seekers in some towns and cities, although there are no published figures showing how many properties have been used for that purpose.

While most of the properties vandalised in Salford are believed to have housed asylum seekers or refugees, reports suggest some did not and that some of the buildings targeted were not even HMOs.

Police said 50 properties had been vandalised, most of them in Salford, with others in neighbouring Tameside and Stockport.

Greater Manchester Police described the attacks as "racially or religiously motivated" and said officers were monitoring social media posts that appeared to encourage the vandalism.

Some accounts sharing footage of the aftermath have described the properties as "migrant HMOs".

When challenged, some users said concerns about "mass immigration" were being ignored. Others said they were concerned about properties housing groups of men "whatever their nationality" and argued it was "unfair" to suggest their posts had fuelled the attacks.

Police have made four arrests and suggested young people are being exploited by adults to carry out the attacks.

• Additional reporting by the Local Democracy Reporting Service

Listen to the best of BBC Radio Manchester on Sounds and follow BBC Manchester on Facebook, X, and Instagram. You can also send story ideas via Whatsapp to 0808 100 2230.