Tl,dr; Probably yes.
Israel justifies demolitions of Palestinian property on three grounds;
administrative (lack of building permit), punitive (relatives of
militant lives there), and military (full-filling a military
objective). Your question is about military demolitions. Two articles
of International Humanitarian Law (IHL) applies here. Article 46 of
the Hague regulations:
In addition to the prohibitions provided by special Conventions, it
is especially forbidden [...] To destroy or seize the enemy's
property, unless such destruction or seizure be imperatively
demanded by the necessities of war;
and article 53 of the Geneva Conventions:
Any destruction by the Occupying Power of real or personal property
[...] is prohibited, except where such destruction is rendered
absolutely necessary by military operations.
So what we are discussing is conduct that is forbidden, unless
specific criteria (in italics) applies. Note that these criteria are
not sufficient and other factors might also have to be taken into
account. B'TSelem argues:
Even in the case of military necessity, [...], the occupier must
comply with the other provisions of international humanitarian
law. Indeed, jurists and international tribunals have firmly
rejected the argument that military necessity prevails over every
other consideration and nullifies application of these other
provisions.
Moreover, the principle of proportionality applies:
[...] [The] principle [of proportionality] also applies to Israel’s
policy discussed in this document. According to the commentary
published by the ICRC on article 53 of the Fourth Geneva Convention,
destruction of property is illegal if the occupier does not “try to
keep a sense of proportion in comparing the military advantages to
be gained with the damage done.”
According to B'TSelem, the wholesale destruction of an entire
neighbourhood on the basis that tunnels exist under it, or that
militans are firing from houses in it, violates the principle of
proportionality:
The IDF forces destroyed entire residential neighborhoods, claiming
that, under some of the houses, tunnels had been dug through which
weapons were being smuggled. In other cases, the army destroyed
dozens of houses on the grounds that Palestinians were firing from
the area at IDF soldiers. The demolition of houses based on this
claim cannot be deemed to meet the conditions required by the
principle of proportionality.
The article The Legality of House Demolitions Under IHL defines
"military necessity" as follows:
Military necessity incorporates clear conditions: (i) the presence
of an immediate and concrete threat, (ii) that the demolition be an
adequate response to the threat, and (iii) that, even if the first
two conditions are fulfilled, such demolition must respect the
principle of proportionality. If the demolition fails to fulfill one
of the criteria, it is illegal.
Israel has many times in the past demolished houses to create "buffer
zones". As a preparation for the 2005 Gaza pull-out, it in 2004
destroyed hundreds of dwellings in Rafah in southern Gaza to create a
300 meters wide "buffer zone" running along the Gaza-Egypt border. The
Human Rights Watch's report Razing Rafah: Mass Home Demolitions in
the Gaza Strip claimed that many of these demolitions were
unlawful and did not meet the threshold of "military necessity". Among
other things, the report failed the Israeli army's argument that
razing homes made smuggling tunnels easier to detect:
The IDF has publicly admitted destroying houses to "weaken the fear
of tunnels" or in response to other hypothetical risks.This doctrine
conflates the legal requirement of absolute military necessity a
strict standard requiring that any property destruction must be
connected to combat with the much broader notion of security.
Recently the UN High Commissioner for Human Rights Volker Türk
warned that creating a one-kilometer buffer zone could be a war
crime. He based his argument on article 53:
The Israeli Defence Forces (IDF) are reportedly destroying all
buildings within the Gaza Strip that are within a kilometre of the
Israel-Gaza fence, clearing the area with the objective of creating
a “buffer zone”. I stress to the Israeli authorities that Article 53
of the Fourth Geneva Convention prohibits destruction by the
Occupying Power of property belonging to private persons “except
where such destruction is rendered absolutely necessary by military
operations”.
Destructions carried out to create a “buffer zone” for general
security purposes do not appear consistent with the narrow “military
operations” exception set out in international humanitarian
law. Further, extensive destruction of property, not justified by
military necessity and carried out unlawfully and wantonly, amounts
to a grave breach of the Fourth Geneva Convention, and a war crime.