Covered entrance I start to construct in Iberian city (7)
I believe the answer is:
Here is my best explanation:
'covered entrance' is the definition.
(I've seen this before)
'i start to construct in iberian city' is the subsidiary indication.
'start to' indicates taking the first letters.
'in' means one lot of letters goes inside another.
'iberian city' becomes 'porto' (Portuguese city**).
The first letter of 'construct' is 'c'.
'ic' inserted into 'porto' is 'portico'.
(Other definitions for portico that I've seen before include "Zeno's teaching colonnade", "Colonnade in front of a building", "Covered porch, perhaps with columns", "Porch with columns", "Covered porch with supporting columns", "Grand porch", "Entrance with a roof supported by columns", "Elaborate porch", "Posh covered entrance to building" and "Porch-like structure with columns".)