Landlord and Tenant in UK Law

If the reversioner wants a leaseback of a flat in respect of which, at the time of the counternotice, there is not a qualifying tenant, he must say so in his counternotice. If he does so, then he will be entitled to the leaseback, so long as there is still no qualifying tenant immediately before acquisition by the nominee purchaser.

(2) As a corollary to the first proposition, a landlord is not entitled to refuse his consent to an assignment on grounds which have nothing whatever to do with the relationship of landlord and tenant in regard to the subject matter of the lease. (See Houlder Bros. & Co. y. Gibbs (supra) a decision which (despite some criticism) is binding on this Court; Bickel v. Duke of Westminster (1977) Q.B. 517).

This arises in a situation where a person is entitled to alternative rights inconsistent with one another. If he has knowledge of the facts which give rise in law to these alternative rights and acts in a manner which is consistent only with his having chosen to rely on one of them, the law holds him to his choice even though he was unaware that this would be the legal consequence of what he did.

The second type of waiver which debars a person from raising a particular defence to a claim against him, arises when he either agrees with the claimant not to raise that particular defence or so conducts himself as to be estopped from raising it. This is the type of waiver which constitutes the exception to a prohibition such as that imposed by section 29(3) of the Landlord and Tenant Act 1954 and other statutes of limitation. The ordinary principles of estoppel apply to it.

Where there is, on the face of it, a complete, bilateral contract, the courts are sometimes willing to add terms to it, as implied terms: this is very common in mercantile contracts where there is an established usage: in that case the courts are spelling out what both parties know and would, if asked, unhesitatingly agree to be part of the bargain.