Maintenance charges should be equal irrespective of size of flat 

2) water charges can depend upon number of inlets in flat 

3) insurance charges can depend upon area of flat 

4) if society refuses to listen to reason file application before cooperative court seek orders to set aside decision of AGM regarding levy of maintenance charges as per area of flat 

You have to follow the  Karnataka State Association laws and rules. 

For the common expenses  society can collect common maintenance like Garbage cleaner, common space electricity bill, watch man salary etc those should be collect equally.

And for sq ft wise sinking fund, building repair outside structure wise, painting etc.

If want all bifurcation formula do let me know.

You need to complaint the said fact to the Dy. Registrar and scrap that illegal resolution. If he is not doing anything you need to go for revision before joint registrar or later approach High court in writ petition

Bring the facts by writing a letter to concerned dy. Registrar of CHS for resolution of your grievances. 

You should object to maintenance charges levied on 3 bedroom flats as maintenance charges should be equal irrespective of size of flat 

2) if AGM refuses to listen take legal proceedings as mentioned herein above 

Draft can be obtained from the particular lawyer on this website.

Serve them with a legal notice for capping the increase to the 30%

Complain to registrar. If no solution than file suit in court and obtain stay.

Just write normal letter citing judgement of Bombay. 

1. In most states including Karnataka where Apartment Ownership Act is in place imposition of maintenance charge varies with the area of flat which is most logical and followed in many states like WB as well.

So if your housing complex is also registered under the Act then the method of increase of charge disproportionately is malicious, unreasonable and arbitrary.

Even if it is not under the said Act then also it is not maintainable.

So depending upon the Act under which it is registered You can refuse to make the payment till the dispute is adjudicated by the adjudicating Body like Competent Authority or the Registrar as the case may be. 

Dear Sir,

The draft of the letter can be prepared by any advocate of your choice and you are suggested to consult the kaanoon forum through "talk to lawyer category". Please be sure that it just a guidance of process and not solicitation etc. In regard to increasing rates by society, you are suggested to put your objection during general body meeting and if not heard, you may complain to registrar's of society against this. 

You have not mentioned that how the society made this decision to increase the maintenance charges and also to switch over to the sq. basis of charging the  monthly maintenance amount.

If these changes were brought after passing a resolution passed by majority members in a special or general meeting of the society members, then all the members are to abide by the decision.

Whether you participated in the meeting or not?

If so, whether you objected to it in the meeting?

Have you given a written representation describing your grievances on this?

Did any other affected member take any steps to curb this extra burden?

What about other affected members, have they accepted the changes?

If not then you gather all of them and issue a notice to the association to reconsider the decision of charging exorbitant charges on very few members.

If necessary an extra ordinary meeting may be convened to decide about this request.

Alternately you an approach the registrar of cooperative society to get your grievances redressed.

You can have your own agenda to be discussed in the next meeting which will include all your proposals as stated here.

You can even mention the hardships you will face due to this sudden increase in the maintenance charges that too exorbitantly.

You can take the support of other affected members to insist your problem in this.

If your pleas are not taken into consideration then you may object to the proposed hike in the charges and get it recorded so that it will be useful to initiate legal steps on this i future on the basis of your protests recorded in the meeting, available in the minutes book of the association. 

Any increase in maintenance or other charges need sanction of General Body. 

you can approach the cooperative deputy registrar of your area for redressal.

1. Any aggrieved owner may file a writ petition against the housing society to challenge the imposition of maintenance charges calculated on sq ft basis on the area of the flat.

2. Serve a lawyer's notice to the association to roll back the hike.

3. If it is not rolled back then a Writ Petition may be filed in the High Court.

The Housing Society cannot arbitrarily enhance the  Maintenance Charges (MC) at their whims and fancies.

MC will be charged equally irrespective of size of flat.

You make a representation to the Society in writing under acknowledgement.

If the Society refuses to your request, you can file complaint with the Registrar of Co-operative Societies seeking direction to set aside the decision of Society to enhance MC.

Your first objective would be to object the proposal of Society for enhancing MC levied on 3BHK, as the MC shall be  collected equally from all the flat owners irrespective of the size of the Flat.

If they refuse to your request and go ahead with their proposal.  

You can proceed as stated above by lodging complaint with Registrar etc.