Church porch
A church porch is a room-like structure at a church's main entrance. In most Christian churches the main door is on the south side, and a Porch protects from the weather to some extent. Some porches have an outer door, others a simple gate, and in some cases the outer opening is not closed in any way.
The porch at St Wulfram's Church, Grantham, like many others of the period, has a room above the porch, which once provided lodging for the priest but now houses Francis Trigge Chained Library. Such a room is sometimes called a parvise
although the word more normally means an open space or colonnade outside the entrance of a church.
In Scandinavia the porch of a church is often called by names meaning weaponhouse. Visitors stored their weapons there because of a prohibition against carrying weapons into the sanctuary, or into houses in general.
Examples
St Wulfram's Grantham, England: The church porch which houses the chained library