17.—(1) In section 16—

“alter or improve”, in relation to a dwelling, includes—

(a) alter a locking system on a door giving entry to the dwelling, and

(b) make an addition to, or alteration of, a building or structure (including any building or structure subsidiary or ancillary to the dwelling),

“behave in a way that is anti-social” means—

(a) engage in behaviour that constitutes the commission of an offence, being an offence the commission of which is reasonably likely to affect directly the well-being or welfare of others,

(b) engage in behaviour that causes or could cause fear, danger, injury, damage or loss to any person living, working or otherwise lawfully in the dwelling concerned or its vicinity and, without prejudice to the generality of the foregoing, includes violence, intimidation, coercion, harassment or obstruction of, or threats to, any such person, or

(c) engage, persistently, in behaviour that prevents or interferes with the peaceful occupation—

(i) by any other person residing in the dwelling concerned, of that dwelling,

(ii) by any person residing in any other dwelling contained in the property containing the dwelling concerned, of that other dwelling, or

(iii) by any person residing in a dwelling (“neighbourhood dwelling”) in the vicinity of the dwelling or the property containing the dwelling concerned, of that neighbourhood dwelling.

(2) The reference in section 16(b) to an act or omission by the tenant shall be deemed to include a reference to an act or omission by any other person who, at the time of the doing of the act or the making of the omission, is in the dwelling concerned with the consent of the tenant.

(3) The landlord shall be entitled to be reimbursed by the tenant any costs or expenses reasonably incurred by him or her in deciding upon a request for consent in relation to the tenant's doing a thing referred to in paragraph (k), (l) or (m) of section 16 (whether the consent is granted or refused).

(4) If the amount of the premium referred to in section 16(j) is, apart for the reason mentioned in that provision, subsequently increased or reduced then the reference in that provision to the increased element shall be construed as a reference to the amount concerned as proportionately adjusted in line with the increase or reduction.