A converted water tower and an 18th-century farmhouse with a contemporary extension are the first two properties to be shortlisted for the House of the Year 2021 award.

The houses were selected by the Royal Institute of British Architects (Riba), Press Association reported.

They featured on the first episode of the new series of Grand Designs: House of The Year.

The award was established in 2013 and is presented to the best new architect-designed house or extension in the UK annually.

The steel water tower is based in rural Norfolk and was built in the 1950s. It has now been converted into a home.

Gazette Series: Water tower (Dennis Pederson/PA)Water tower (Dennis Pederson/PA)

The next property, named the House on the Hill, is a contemporary extension to an 18th-century farmhouse in Gloucestershire overlooking the Wye Valley.

Previous winners of the top architectural prize include McGonigle McGrath for House Lessans in 2019 and HaysomWardMiller for Lochside House in 2018.

Gazette Series: House on the Hill (Paul Riddle/PA)House on the Hill (Paul Riddle/PA)

The new series of Grand Designs: House Of The Year will present all seven shortlisted properties.

The four-part series of Grand Designs: House Of The Year will showcase the seven shortlisted properties, with the first episode having aired on November 17.

The winner of the Riba House of the Year 2021 prize will be announced on the final episode which is due to air on December 8.

Grand Designs: House Of The Year will air on Wednesdays at 9pm on Channel 4.