When comparing properties we usually look at location, price and possession date. These are no doubt important parameters for short-listing, however there are many more important things to check before you finalize a deal.Ask for copies of all necessary permissions prior to making any financial commitment. Check the following documents and clearance certificates to avoid getting into any legal tangle in future:Title deed is the most important document as it gives details about ownership, rights, obligations and mortgages on the property. So it validates whether the land where the project is coming up has been registered and development rights transferred. Get a copy of it from the builder and cross-check the information with the land record office.A 'certificate of commencement' is mandatory to commence any construction of a property. The certificate is issued by the town planning and engineering department post the inspection of the basic foundation for a superstructure and building boundaries. This also means that the builder would have obtained the required licenses, sanctions and permissions for the map that are required before you can even start excavating.It is good to run an additional check and verify that the building plan and layout plan has been approved and no byelaw applicable in the area has been broken. Make sure that the floor where you have booked your flat has been approved in the building plan.The layout should be in accordance with the National Building Code of India (NBC). NBC is a comprehensive guideline, a code, for regulating the building construction activities across the country. Get this document verified with the local municipal authorities.Also, some projects claim a 'green status'. In that case it should be either certified by the Indian Green Building Council or be rated by Green Buildings Rating System India (GRIHA), a TERI University initiative. The focus areas of all such certification for a building are energy, water and waste management. There are a couple of other rating systems also available right now in India, but GRIHA is the most popular and has standardized norms.It is illegal to have residential properties on a commercial or industrial zone. Apply to the urban development authority and check the certificate to ensure that the property you plan to purchase is in the residential zone. Sometimes the land will be in what is called a 'converted zone'. Cities are expanding and often agricultural land is converted for non-residential usage by paying a fee to the government. In such a case, check for the endorsement order given by the tehsildar or deputy commissioner of the zone that licenses residential construction on that land.Often builders claim future infrastructural development of the area such as upcoming metro or highway near the project. Don't believe everything blindly. Look at the area's master planning to verify. These plans are easily available with the town planning department.The builder should also be able to give you a copy of the urban land ceiling NOC (if applicable), an environment clearance NOC as well as NOCs from the electricity, water and lift authorities, if there is one.An easy way to verify that the project has clean paperwork is to see if it has loan approvals from financial institutions. Banks have stringent lending rules and do their necessary due diligence before clearing loans. However, this is not always error-free and there have been many cases in the past where the builder had bank support, but the project landed in legal troubles. It is therefore better to get professional help. If necessary get a paid opinion from a lawyer who specializes in property transactions and get all documents verified.