The total investment in the fund now stands at £320,000.
Graham Bell, finance director at Countrywide, said: “Countrywide is excited and proud to support the UK’s first property technology accelerator.
“We are passionate about supporting innovation in our sector and were one of the early investors in both Rightmove and Zoopla, amongst others.
“We hope companies who join PiLabs will benefit from the expertise that our nationwide business has to offer, and we look forward to working with the teams to help them grow their businesses further.”
Five start-ups, which were selected from over 200 business plans, have joined the fund’s first accelerator programme of 2015, with another cycle scheduled for later this year.
Faisal Butt, founder and chief executive of Pi Labs, said: “It is amazing that the property community is coming together to back innovation and help the industry progress and adapt to the digital age.
“We received over 200 business plans from talented management teams from across the globe, and we believe we have selected the best 5, which in our view, are well positioned to innovate within the property industry.
“We firmly believe we will find the next Airbnb from the Pi Labs platform.”