A 350-year-old building, believed to be Dublin’s oldest house, will open its doors to the public for the first time this weekend.

Number 9/9a Aungier Street is one of the earliest buildings in the Aungier Estate, Dublin’s first planned post-medieval housing development, pre-dating the construction of Georgian Dublin.

The four-storey building on the east side of the street - which runs south from South Great George’s Street - was constructed the same year St Stephen’s Green was enclosed. The house combines the timber framing techniques of medieval Ireland with mass masonry construction, making it a link between the medieval and Georgian cities.

Built in 1664 as a home for the elite of Dublin society, it became a merchant’s house during the 18th and 19th centuries and tenements and flats in the 20th century.

It is one of the most intact structures of its period to have survived anywhere in the country and is a Registered National Monument as well as a Protected Structure.

However, its 20th century façade meant its age and significance went unnoticed until the 1990s when a planning application to convert the building into apartments brought it to light.

The application was never granted and the house, which had fallen into a perilous state of repair, is now undergoing a major conservation programme.

It is one of the buildings which will feature in the Irish Architecture Foundation’s Open House Dublin weekend. Over the weekend more than 100 public, private, commercial, industrial and domestic buildings, some of which are not usually open to the public, will be on show with free guided tours.

The line-up includes some of the city’s most famous historic buildings including City Hall, the Casino at Marino and the Mansion House, as well as lesser known architectural gems such as Tailor’s Hall, the City Assembly House and the Iveagh Trust Museum Flat.

Several modern buildings will also open their doors including the Convention Centre, the Commissioners of Irish Lights headquarters, and Irishtown Garda station.

Details of the buildings on show, as well as opening times are available at openhousedublin.com