A local authority or development corporation may not incur expenses in—
providing dwellings by the conversion of houses or other buildings, or
carrying out works required for the improvement of dwellings, with or without associated works of repair,
except in accordance with proposals submitted by the authority or corporation to the Secretary of State and for the time being approved by him.
The Secretary of State's approval may be given subject to such conditions, and may be varied in such circumstances, as appear to him to be appropriate; but before varying the terms of an approval he shall consult the authority or corporation concerned.
In this section "dwelling" has the same meaning as in Part XV (grants for works of improvement, repair and conversion).