The new academic year is about to begin, meaning hundreds of thousands of students are headed to university for the first time, or returning after the summer break. Unless they are staying at home, they all need somewhere to live – and that presents a huge opportunity for private landlords. The constant churn of tenants and potential for wild parties mean renting to students isn't for the faint-hearted. But landlords could be tempted by the fact student lets offer some of the best returns on the market, according to data from buy-to-let mortgage lender Paragon Bank.Some are struggling to make the numbers stack up in the mainstream market amid higher mortgage rates, upkeep costs and service charges alongside more regulation and a less friendly tax regime.While the average rental yields for typical buy-to-let rental investments are around 6 per cent, student rentals in some locations can yield over 9 per cent.The yield is the percentage an investor can expect to make back on the purchase price of their property each year.For example, a 5 per cent yield on a £200,000 property would amount to £10,000 per year in rental income, or £833.33 per month. Student digs: Properties in popular student postcodes generate average yields of 7.32% compared to 6.86% for non-student postcodes, according to Paragon BankWhere are student lets most lucrative? Paragon Bank has shared data with This is Money based on the properties it has provided mortgages on in popular student postcodes. It shows that Stoke-on-Trent offers landlords the strongest rental yields among the UK’s leading university locations.The city, which serves the University of Staffordshire and nearby Keele University, recorded a student property yield of 9.42 per cent. This is based on average annual rental income of £14,222 and a typical property valuation of £150,982.Plymouth ranked second, generating a typical yield of 9.27 per cent. Student properties in the city delivered average annual rental income of £35,224, against an average valuation of £379,881.Cities with Russell Group universities also feature prominently in the top 15 rankings. Liverpool, Cardiff, Edinburgh, York, Leeds, Nottingham, Sheffield, Durham, Exeter and Southampton all appear among the 15 highest-yielding locations. Student landlords in Liverpool, home to the University of Liverpool and Liverpool John Moores, can typically expect to achieve a yield of 8.86 per cent, based on annual rental income of £26,399 and an average property valuation of £297,951.Cardiff student lets produce average returns of 8.27 per cent while Edinburgh follows closely at 8.23 per cent. York and Leeds each generated yields above 8 per cent. But property experts say the decision to invest in student property should not be taken lightly. 'Student property is a specialist market,' said Louisa Sedgwick, managing director of Mortgages at Paragon Bank. 'Landlords need to understand local demand, the type and quality of accommodation students require and the responsibilities associated with managing shared homes.' Chris Sykes, a mortgage adviser at MSP Financial Solutions says:'Although the headline rents are higher, student lets will often go through more wear and tear than a professionally let house of multiple occupancy.'I remember my own university days. My house that housed eight of us was always a mess - no matter how many cleaning schedules I pinned to the fridge. 'Students will have parties, they may cause noise complaints with neighbours, smoke residue inside a property is a frequent one too – so I’d imagine the insurance side of things is more expensive also.'Sykes also says student landlords are nervous about the implications of the Renters Rights Act.