Buying a home is the most expensive financial transaction most people ever make, and yet many will take this important step without asking the basic question - 'Is this property sound?'

Surveys are designed to give you the information you need to make an informed and sensible offer on your future home. Both consumer's Association publishers Which? Magazine and The Council of Mortgage Lenders advise you to arrange a survey before buying a property - don't just rely on a valuation.

A survey by a chartered surveyor can prevent expensive mistakes and substantially reduce the risk inherent in such a large transaction. But many people do not know what is the best survey for them or how to go about getting one done. A new publication from the Royal Institute of Chartered Surveyors "Understanding Property Surveys" can help change this.

A valuation is an inspection carried out on behalf of your mortgage lender to determine the amount and terms of a mortgage offer. Your mortgage lender will probably ask you to pay for the valuation and will send you a copy of the report.

A valuation is not a survey. It's a limited inspection to identify problems that affect the security of your mortgage lender's loan. A property can have defects that are critical to a prospective buyer, but are not of concern to the mortgage lender and therefore won't appear in a valuation report. That's why you should not just rely on the information provided by a valuation when deciding whether or not to purchase a property.

You should have a survey carried out on the property you intend to buy, and carefully consider its results before entering into a contract to buy it (or before making an offer in Scotland). Depending on the seriousness of any defects and costs of necessary repair work, you could try to re-negotiate the purchase price to reflect the cost of repairs in your offer or decide not to purchase the property at all.

Surveyors should comment on all parts of a property that are readily accessible but they are not obliged to inspect areas that are difficult to access. They won't lift carpets, shift furniture, use a ladder to inspect the roof or move items stored in the loft.

Similarly, since most surveyors are not experts in electrics or plumbing, they won't test services such as the wiring and water supply. However, they may comment on their condition. Where necessary, surveyors will recommend that an expert examination be carried out.

There are two main types of survey:

• Homebuyers survey and valuation (also known as HSV, HBSV or Homebuyers report)
• Building survey

An HSV is a service carried out to a standard format, defined by RICS (Royal Institution of Chartered Surveyors), designed for properties built after 1900, which are of conventional construction and in reasonable condition. An HSV includes the following information:

• The property's general condition.
• Any significant defects, in accessible parts of the property, which may affect its value.
• Urgent and significant matters that need assessing before entering into exchanging contracts (or before making an offer in Scotland) including recommendations for any further specialist inspections.
• Results of testing walls for dampness and timbers for damage including woodworm or rot.
• Comments on the existence and condition of damp-proofing, insulation and drainage (although the later will not be tested).
• The recommended reinstatement cost for insurance purposes (the anticipated costs of re-constructing a building in the event of damage by an insured risk eg. Fire) this is not the same as the market value of the property.
• The value of the property on the open market.

An HSV is not a detailed survey of every aspect of the property and focuses only on significant and urgent matters. It's not suitable for properties built before 1900, those in need of renovation or that you are planning to extend.

A building survey is a comprehensive inspection suitable for all properties but especially recommended for:

• All listed buildings
• Those built before 1900
• Any building constructed in an unusual way regardless of its age
• Properties you are planning to renovate or alter in any way
• Properties which have already had extensive alterations

A building survey involves a detailed examination of all accessible parts of a property and can be tailor-made to suit your individual needs and concerns. A building survey includes the following:

• All major and minor faults.
• The implications of any defects and possible cost of repairs.
• Results of testing walls for dampness and timbers for damage including woodworm or rot.
• Comments on the existence and condition of damp-proofing, insulation and drainage (although the latter will not be tested).
• Extensive technical information on the construction of the property and details about material used in construction.
• Iinformation on the location.
• Recommendations for any further specialist inspections.

A building survey does not include a valuation, although your surveyor should be able to provide a separate valuation report if required.

Surveys are essential in helping you to decide to purchase a property. So it is important to ensure you appoint the right type of surveyor for your needs and to get best advice. Chartered surveyors are professionals whose academic qualifications and training have been approved by RICS. They are required to follow a strict code of ethical conduct and professional standards. To find an chartered surveyor in your area, call the RICS Contact Centre on: 0870 333 1600