Related Rule
Netherlands
Practice Relating to Rule 10. Civilian Objects’ Loss of Protection from Attack
The Military Manual (1993) of the Netherlands considers that civilian objects, such as houses and school buildings, can be used in such a way that they become military objectives, for example if they house combatants or are used as commando posts. 
Netherlands, Toepassing Humanitair Oorlogsrecht, Voorschift No. 27-412/1, Koninklijke Landmacht, Ministerie van Defensie, 1993, p. V-3.
The Military Handbook (1995) of the Netherlands states that “non-military buildings and other objects not used for military purposes or of no military importance” may not be attacked. 
Netherlands, Handboek Militair, Ministerie van Defensie, 1995, pp. 7–36 and 7–43.
The Aide-Mémoire for IFOR Commanders (1995) of the Netherlands prohibits attacks on “objects with a strict civilian or religious character, unless they are used for military purposes”. 
Netherlands, Aide-Mémoire voor IFOR Commandanten, First Edition, 21 December 1995, § 12.
The Military Manual (2005) of the Netherlands states:
0512. It is possible for objects to be classed, on the one hand, as military while, at the same time, they have a civilian purpose. These are known as mixed objects. Examples are a bridge, which can definitely count as a military objective while at the same time its internal structure carries the energy supply to the civilian population of the region. A television mast may not only serve a civilian purpose but perform a function in the telecommunications network of the armed forces …
0546. When attacking mixed objects (see point 0512), it must be carefully considered whether the military advantage expected from eliminating the military element of the mixed objective outweighs the damage done to the civilian population, by damaging or destroying the civilian element of the mixed object or ending its civilian function. In any case, the disabling or destruction of the military element must yield a clear military advantage (cf. AP I [1977 Additional Protocol I] Article 52). In addition, the civilian population must not be excessively affected (cf. AP I Article 51). 
Netherlands, Humanitair Oorlogsrecht: Handleiding, Voorschift No. 27-412, Koninklijke Landmacht, Militair Juridische Dienst, 2005, §§ 0512 and 0546.
In its chapter on non-international armed conflict, the manual states:
Civilian objects may not be attacked or destroyed, unless they form a military objective, i.e., if there is a military need to do this (e.g., destroy a house because it is in the line of fire, or an observation post or snipers’ position in a church tower). 
Netherlands, Humanitair Oorlogsrecht: Handleiding, Voorschift No. 27-412, Koninklijke Landmacht, Militair Juridische Dienst, 2005, § 1032; see also § 1037.
The Military Manual (1993) of the Netherlands states: “In case of doubt whether an object which usually serves civilian purposes, such as a house, a school, a church, is used for military purposes, it must be assumed to be a civilian object.” 
Netherlands, Toepassing Humanitair Oorlogsrecht, Voorschift No. 27-412/1, Koninklijke Landmacht, Ministerie van Defensie, 1993, p. V-3.
The Military Manual (2005) of the Netherlands states: “In the event of doubt whether an object normally used for civilian purposes, e.g., a house, a school, a church, is being used for military purposes, it must be assumed that it is a civilian object.” 
Netherlands, Humanitair Oorlogsrecht: Handleiding, Voorschift No. 27-412, Koninklijke Landmacht, Militair Juridische Dienst, 2005, § 0513.