HMO landlords spend 45% of gross rental income on running costs, compared to 25% for non-HMO landlords.
This includes money spent on maintenance, servicing, insurance, utilities, professional fees and regulatory compliance.
Average total annual expenditure stands at £19,604 for landlords with non-HMO properties, rising to £35,720 for those operating HMOs, research from software company Pegasus Insight shows.
This highlights that, despite the potentially greater returns associated with HMOs, the cost of maintaining these rentals is a significant barrier.
Mark Long, Pegasus founder and director, said: “Maintenance and repairs have always been a core cost for landlords, but what we’re seeing now is a step-change in scale.
“Even with yields at multi-year highs, a growing share of rental income is being absorbed by day-to-day running costs and compliance demands.
“For many landlords, particularly those with older stock or more complex portfolios, the challenge is no longer generating income, it’s protecting margins in the face of rising costs.”
The average buy-to-let portfolio generates gross income of £79,000 per year.
In some cases, maintenance and repairs amounted to 40% of total landlord expenditure.
Long added: “Our wider research shows that landlords are investing more than ever to keep properties safe, compliant and habitable, yet maintenance remains a pressure point in the rental relationship.
“Rising labour costs, supply chain issues and higher tenant expectations all make delivering timely repairs more challenging.
“The risk is that sustained increases in upkeep costs ultimately feed through into higher rents, as landlords look for ways to fund the ongoing investment required to keep properties in good condition.”