The Government considered allowing families to extend their homes by as much as 70 square metres as part of a review of building regulations.
The move would have resulted in homeowners being allowed build extensions around two-thirds the size of an average three-bed house without any planning permission and would have proved highly popular among families hoping to trade-up to a larger property.
The proposal was suggested by Housing and Planning Minister Paudie Coffey during a review of building regulations last summer, documents released under Freedom of Information show.
The review resulted in some changes to the regulations, including exempting self-built homes and extensions from the requirement to be certified by a professional as being constructed in line with the building code.
Removing the requirement to secure planning permission would have helped homeowners expand their living space without having to compete for a larger home in a housing market when few new properties are coming on stream.
Currently, homeowners can extend without planning permission if the works do not increase the floor area by more than 40sqm and the structure is not higher than the existing house.
Mr Coffey said the move was eventually dropped after consultation with advisers.