All searches of premises (including consent searches other than routine scene-of-crime searches or responses to calls, alarms or bomb threats) are governed by Code B.
The police may search any premises with the occupier's consent; the officer in charge of such a search should make it clear to the occupier that he is not obliged to consent (paragraph 5.2). In the case of a lodging house, student hall of residence or similar accommodation, consent should normally be obtained from the tenant(s) of the room(s) to be searched, rather than from the landlord (note 5A).
A "consent search" may also be carried out without first seeking express consent where it is reasonable to assume that an innocent occupier would agree and that obtaining consent would cause him undue inconvenience (paragraph 5.4). For example, if a suspect has run away from the scene of a midnight crime and has disappeared in a certain street, the police check each of the gardens to see whether he is hiding there, without first waking all the occupiers (note 4C).
Police and Criminal Evidence Act 1984 s.18(1)
... a constable may enter and search any premises occupied or controlled by a person who is under arrest for an indictable offence, if he has reasonable grounds for suspecting that there is on the premises evidence ... that relates to that offence, or to some other indictable offence which is connected with or similar to that offence.
Jeffrey v Black  1 All ER 555, QBD
A student was arrested for stealing a sandwich from a pub; the police searched his flat, where they found a quantity of drugs. At his trial for possession of drugs the justices found the evidence inadmissible and dismissed the charge, but the High Court remitted the case for rehearing by a new bench. Although the police had no right to search his home without his consent (because they had no reasonable grounds to suspect large-scale sandwich theft!) that was not in itself a reason to exclude the evidence.
Under section 32(2) of the Police and Criminal Evidence Act 1984, where a person has been arrested for an indictable offence, a constable may enter and search any premises in which the person was at or immediately before the time of his arrest, for evidence relating to that offence.
In addition, the police have powers under s.17 of the Police and Criminal Evidence Act 1984 to enter and search premises, using reasonable force if necessary,
- to arrest a person for an indictable offence, or for certain other offences;
- in "hot pursuit" of a prisoner at large; or
- to save life or limb or prevent damage to property.
D'Souza v DPP  4 All ER 545, HL
Ms D'Souza's mother had escaped from a psychiatric hospital where she was being detained, and police officers came to D'Souza's house to take her back. They had no warrant, and D'Souza and her father resisted their entry, whereupon they were charged with assaulting police officers in the execution of their duty. Their conviction was quashed by the House of Lords: since the police had not been in "hot pursuit" of D'Souza's mother they had no power of entry without a warrant, and were consequently not acting in the execution of their duty when they forced an entry.
Searches should be carried out with the occupier's consent if possible, and must be made at a reasonable hour unless this would be likely to frustrate the purpose of the search (Paragraph 6.2). Before entering occupied premises, the officer in charge must identify himself, state the purpose of the search and the grounds for undertaking it (paragraph 6.5), and give the occupier a written notice of his rights (and a copy of the warrant, if appropriate), unless there is reason to think this would lead to the disappearance of the items sought (paragraph 6.8).
O'Loughlin v Chief Constable of Essex  1 WLR 374, CA
Police officers arrived at O'Loughlin's house late one night to arrest his wife for causing damage to a neighbour's car. When they asked to be allowed to speak to his wife, O'Loughlin refused to let them in; they then forced their way in and arrested O'Loughlin (who continued to resist) for offences against public order. O'Loughlin was bound over to keep the peace, and subsequently brought a civil action for assault; the judge found as a fact that the police had not told O'Loughlin they were exercising their statutory power of entry under s.17, and ruled that O'Loughlin's claim must succeed. The Court of Appeal agreed, and said a police officer exercising his statutory power of entering a home using reasonable force should always give a reason justifying his exercise of that power to any occupant seeking to prevent his entry, unless circumstances made it impossible, impracticable or undesirable for him to do so. The obligation to inform a citizen why his liberty is being interfered with, although not absolute, is a strong one.
DPP v Meaden  4 All ER 75, QBD
Police officers searching for drugs required the occupier to move into a particular room while they searched the rest of the building, and used force when he resisted. Meaden was charged with assaulting a constable, and the High Court said the police had been acting lawfully: it may be reasonable for them to restrict the occupier's movements while a building is being searched.
If the occupier wishes a friend, neighbour or other person to be present as a witness to the search, this must be allowed unless the officer in charge has reasonable grounds for believing this would seriously hinder the investigation (paragraph 6.11). It is not clear from the Code whether the friend's movements could also be restricted as in Meaden: if so, this provision would give the occupier very little protection.
Any search must be proportionate to its legitimate objectives, and must be conducted with due consideration for the property and privacy of the occupier of the premises searched, with no more disturbance than necessary (paragraph 6.10). Reasonable force may be used only where this is necessary because the owner does not or cannot cooperate (paragraph 6.6), and premises that have been entered by force must be left secure (paragraph 6.13), but no compensation is normally payable for any damage caused by the use of reasonable and necessary force.
The search itself must be limited to a reasonable search for the particular person(s) or item(s) sought, bearing in mind their nature and size (Paragraph 6.9). A search for stolen TV sets should not involve turning the occupier's girl friend out of her bed!
Police and Criminal Evidence Act 1984 s.19
(2) A constable who is lawfully on premises may seize anything which is on the premises if he has reasonable grounds for believing that it has been obtained in consequence of the commission of an offence, and that it is necessary to seize it in order to prevent it being concealed, lost, damaged, altered or destroyed.
(3) A constable who is lawfully on premises may seize anything which is on the premises if he has reasonable grounds for believing that it is evidence in relation to an offence which he is investigating or any other offence, and that it is necessary to seize it in order to prevent it being concealed, lost, damaged, altered or destroyed.
Special rules apply to items subject to legal professional privilege, excluded material (personal records, human tissue and journalistic material) held in confidence, and special procedure material (mainly business records), which cannot generally be searched for without the authorisation of a circuit judge, but which (except for those subject to legal professional privilege) can be seized if they are found and come within the terms of s.19.