A new survey of 1,000 landlords shows that 88% have renovated at least one rental property in the past five years — and the financial gains can be significant.

According to analysis by The Mortgage Works (Nationwide), adding an extension or loft conversion can increase a property’s value by 24%. On the average home in England and Wales (£272,995), that’s an uplift of more than £65,000.

Other value-boosting improvements include:

• +13% for an extra bedroom
• +8% for an additional bathroom
• +3% for a 10% increase in floor area

For landlords, these upgrades don’t just raise capital value — they also increase rental income. An extension or loft conversion can boost rents by 26%, a new double bedroom by 12%, and a second bathroom by 6%.

Energy efficiency improvements can also enhance value. A BTL property rated A or B attracts a 10.9% premium compared with one rated D. Among landlords who made green upgrades, the most common were solar panels (37%), insulation improvements (33%), and EV charging points (32%).

Nationwide reports that solar panel adoption continues to grow, with nearly 1.5 million homes in England now featuring installations.

The research highlights that strategic renovations — especially those adding space or improving EPC ratings — can deliver strong returns for landlords both through increased asset value and higher rental yields.