Hello Sara and thanks for your essay.

Generalizations and simplifications

One thing to watch out for in IELTS essays is over-generalization, over-simplification, or inadequate development of ideas. Have a look at the official descriptors under the headings 'Task Response' and 'Coherence and Cohesion'
Your challenge in this essay is to give the main reasons why many older buildings are being demolished in many countries. The obvious answers would be ease of maintenance, investment or property speculation, the desire for a more modern appearance, the decay or collapse or danger posed by poorly maintained old buildings, city-wide development plans, increased population density requiring taller buildings, changes in urban use and zoning, population moves - a long list. It's probably better to give the most obvious ones first. You have indeed given some good answers, but this one is a little unusual:

Additionally, the historic monuments are for point of attack for the terrorists to revenge the country. That is the reason for demolition of many temples and ancient buildings in few countries

Again, on generalization avoid using the word 'men' (Paragraph 3)

With increase in the current land value, men destroy their outfashioned house to either sell it or build apartments to gain profit. This saves their money from unnecessary expenditure on repairing the old buildings.

This could be rewritten:

With the increase in the value of land, developers demolish old-fashioned houses and build newer apartments or offices to gain profit. New construction also avoids the need to spend money repairing old buildings.

Also, But, And, For, So...
Try to avoid using 'also' at the start of a sentence. You can also often leave out "there is\there are":

Also there must be volunteers from the local community to raise fund for the heritage conservation.

This could be rewritten:

Volunteers from the local community can also raise funds to conserve their heritage.

Hello Kim

This essay is well organized and fully developed. You spent a little more time on the reasons why old buildings are being knocked down than on why they should be preserved, but that's OK. It's easy to read and the ideas flow from one to another (this is what is meant in the descriptors for IELTS Task 2 under Coherence and Cohesion).

You have some spelling errors which I won't look at here - you can fix these easily! Here are some small usage and grammar points:

This essay will explain the reasons why new builiding are taken place of old builing.

This essay will explain why new builidings are taking the place of old buildings.

high raised builing => high-rise buildings

Old houses have gardens which take up a large land

Old houses have gardens which take up a lot of land

You have some very good sentences which just need a little work:

Legulation can be established to protect buildings from demolishing and any modifications should acquire permits from the government. 

Legislation can be established to protect buildings from being demolished and any modifications should require permits from the government.

Overall, some very good ideas and sentences and a natural feel. Well done.