If a question arises whether the withholding of a consent required by virtue of section 97 (landlord's consent to improvements) was unreasonable, it is for the landlord to show that it was not.
In determining that question the court shall, in particular, have regard to the extent to which the improvement would be likely—
to make the dwelling-house, or any other premises, less safe for occupiers,
to cause the landlord to incur expenditure which it would be unlikely to incur if the improvement were not made, or
to reduce the price which the dwelling-house would fetch if sold on the open market or the rent which the landlord would be able to charge on letting the dwelling-house.
A consent required by virtue of section 97 may be validly given notwithstanding that it follows, instead of preceding, the action requiring it.
Where a tenant has applied in writing for a consent which is required by virtue of section 97—
the landlord shall if it refuses consent give the tenant a written statement of the reason why consent was refused, and
if the landlord neither gives nor refuses to give consent within a reasonable time, consent shall be taken to have been withheld.