Related Rule
United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 50. Destruction and Seizure of Property of an Adversary
The UK Military Manual (1958) recalls: “The destruction or seizure of enemy property, whether it belongs to private individuals or to the State, is forbidden unless the damage or seizure is imperatively demanded by the necessities of war.” 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 588; see also § 616.
The manual also states:
Once a defended locality has surrendered, only such further damage is permitted as is demanded by the exigencies of war, for example, the removal of the fortifications, demolition of military buildings, destruction of stores, and measures for clearing the foreground. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 287.
In addition, “extensive destruction and appropriation of property not justified by military necessity and carried out unlawfully and wantonly” constitute grave breaches of the 1949 Geneva Conventions and war crimes. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 625(c) and (d).
The UK LOAC Pamphlet (1981) provides: “It is forbidden to destroy or requisition enemy property unless it is militarily necessary to do so.” 
United Kingdom, The Law of Armed Conflict, D/DAT/13/35/66, Army Code 71130 (Revised 1981), Ministry of Defence, prepared under the Direction of The Chief of the General Staff, 1981, Section 4, p. 15, § 6.
The Pamphlet also contains a rule for non-commissioned officers, stating: “Enemy property is not to be taken, damaged or destroyed unless there is a military need to do so.” 
United Kingdom, The Law of Armed Conflict, D/DAT/13/35/66, Army Code 71130 (Revised 1981), Ministry of Defence, prepared under the Direction of The Chief of the General Staff, 1981, Annex A, p. 46, § 8.
With respect to occupied territory, the manual states: “The destruction of property is forbidden except where absolutely necessitated by military operations.” 
United Kingdom, The Law of Armed Conflict, D/DAT/13/35/66, Army Code 71130 (Revised 1981), Ministry of Defence, prepared under the Direction of The Chief of the General Staff, 1981, Section 9, p. 35, § 12.
The UK LOAC Manual (2004) states in its chapter on occupied territory:
Any destruction of enemy property, whether it belongs to private individuals or the state, is prohibited unless the destruction is absolutely necessitated by military operations. Extensive destruction and appropriation not justified by military necessity and carried out unlawfully and wantonly is a grave breach of the [1949 Geneva Convention IV]. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 11.75.
The manual specifies:
Extensive destruction not justified by military necessity, particularly of things indispensable to the survival of the civilian population (including food, agricultural areas, drinking water installations, irrigation works and the natural environment) with a view to denying them to the civilian population or the adverse party is prohibited and may amount to a grave breach. … The cumulative effect of this is to ban the type of general destruction known as a “scorched earth policy” in occupied territory. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, §§ 11.91–11.91.1.
In its discussion on siege warfare, the manual states:
Once a defended locality has surrendered, or been captured, only such further damage is permitted as is demanded by the exigencies of war, for example, removal of fortifications, demolition of military structures, destruction of military stores and measures for the defence of the locality. It is not permissible to destroy a public building or private house because it was defended. Looting is prohibited and the rules for the protection of civilians and civilian objects continue to apply.” 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 5.35.2.
With regard to internal armed conflict, the manual provides:
15.17. It is prohibited to destroy or seize the property of an adversary unless such destruction be imperatively demanded by the necessities of the conflict.
15.17.1. Property may not be destroyed unless it is a military objective and it is militarily necessary to do so. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, §§ 15.17–15.17.1.
In addition, the manual notes:
Grave breaches under the Geneva Conventions consist of any of the following acts against persons or property protected under the provisions of the relevant convention:
d. extensive destruction and appropriation of property, not justified by military necessity and carried out unlawfully and wantonly. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 16.24.
Lastly, the manual states:
The Hague Regulations 1907 are now recognized as part of customary law. Those regulations provide that the following acts are “especially forbidden”:
g. to destroy or seize the enemy’s property, unless such destruction or seizure be imperatively demanded by the necessities of war. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 16.27.
The UK Geneva Conventions Act (1957), as amended in 1995, punishes “any person, whatever his nationality, who, whether in or outside the United Kingdom, commits, or aids, abets or procures the commission by any other person of, a grave breach of any of the [1949 Geneva] conventions”. 
United Kingdom, Geneva Conventions Act, 1957, as amended in 1995, Section 1(1).
Under the UK ICC Act (2001), it is a punishable offence to commit a war crime as defined in Article 8(2)(a)(iv), (b)(xiii) and (e)(xii) of the 1998 ICC Statute. 
United Kingdom, ICC Act, 2001, Sections 50(1) and 51(1) (England and Wales) and Section 58(1) (Northern Ireland).
In 2004, during a debate in the House of Commons, the UK Parliamentary Under-Secretary of State, Foreign and Commonwealth Office, stated:
The construction of the barrier in the Occupied Territories is in violation of the Hague Regulation of 1907 and Article 53 of the 4th Geneva Convention, because the confiscation of Palestinian land and destruction of agriculture and buildings is not militarily necessary. The barrier could and should be built on or within the Green Line. 
United Kingdom, House of Commons, Statement by the Parliamentary Under-Secretary of State for Foreign and Commonwealth Affairs, Foreign and Commonwealth Office, Hansard, 19 April 2004, Vol. 420, Debates, col. 334W.
In 2004, during a debate in the House of Commons, the UK Parliamentary Under-Secretary of State, Foreign and Commonwealth Office, stated:
Let me be clear: destruction of property in the construction of the barrier in occupied territory is not justified by absolute military necessity and is therefore unlawful under the terms of the fourth Geneva Convention.
Where the barrier separates Palestinians from Palestinians, rather than Palestinians from Israelis, it does not appear to have taken a route decided solely on grounds of security, and the impact on the daily lives of Palestinian people has been dreadful. Palestinian farmers are being separated from their fields, children from their schools and the sick from hospitals. The Government believe that building a barrier on occupied land is illegal, that the humanitarian impact is unacceptable and that routing the barrier through Palestinian land is not necessary to protect Israeli security.
We continue to recognise Israel’s right to defend itself, but reiterate the need for Israel to act in accordance with international law. We call on Israel to reroute the barrier, away from the occupied territories. 
United Kingdom, House of Commons, Statement by the Parliamentary Under-Secretary of State for Foreign and Commonwealth Affairs, Foreign and Commonwealth Office, Hansard, 20 July 2004, Vol. 424, Debates, col. 58WH.
The UK Government Strategy on the Protection of Civilians in Armed Conflict (2010) states: “Civilian property must not be targeted.” 
United Kingdom, Foreign and Commonwealth Office, Government Strategy on the Protection of Civilians in Armed Conflict, March 2010, p. 4.