New windows must match the design and dimensions of the original ones
Rules banning the use of uPVC windows in Hartlepool's conservation areas have been relaxed.
The council had only permitted traditional timber windows in areas of special special architectural or historical interest.
UPVC windows can now be installed provided the design and dimensions match those of the original window.
The change does not apply to listed buildings, where owners must still use traditional designs and materials.
Hartlepool's conservation areas cover Church Street, Elwick, Greatham, Grange, the Headland, Park, Seaton Carew and Stranton.
Councillor Rob Cook, chairman of the council's planning committee, said: "We have made this change after very careful consideration and in the light of the increasing interest in uPVC windows among residents.
"We remain very committed to preserving and enhancing those areas, but we are balancing this with a more flexible approach to the use of modern materials."