Student flats should be big enough for social housing tenants to live in if they cannot be filled by students, Wales' housing minister has said.
Julie James suggested the rules could change so all newly-built homes can potentially be offered to councils or housing associations.
It follows concern about developers failing to fill upmarket student accommodation, particularly in Cardiff.
Some flats have changed use so they can be let to other tenants or tourists.
But unlike homes in the private sector, housing association and council homes have to meet Welsh Government standards, including being built to a minimum size.
At a press briefing, Ms James said the Welsh Government would consult on whether to change building regulations so all new homes comply to the same standards.
She said: "It's a concern not just about student flats, but just about the type of housing that's built generally and what we can do with it if it's not utilised for the purpose it was originally intended.
"I'm very keen - we'll be consulting shortly - about changing the space standards in Wales so that everything is built to social housing standards.
"So a student flat that's built to social housing standard can be taken over by a registered social landlord and utilised for the desperate need for social housing that we have.
"But if it's built to a much smaller standard then it can't be utilised in that way and that seems a shame to me."
Around 4,000 new social homes a year are needed to keep up with demand, she said.