As with all investments, the value of a property can go down as well as up.

Past performance is not a guide for the future. If your mortgage loan exceeds the property value, you will have negative equity. Also factor in the costs of selling, such as using an estate agency, into your net value. However, if you pick the right area, and are realistic about returns, you can reduce the risks.

Unforeseen structural problems could prove expensive, so budgeting for regular maintenance is crucial, as is having the right level of buildings insurance.

Rental income from buy-to-let properties can vary: if the market is saturated with rental properties, your annual income may remain static or even fall. The condition of your property will also impact your rental levels. You need to build leeway into the rent to allow for periods when the property might be empty between lets (it takes on average four weeks to let a property), and to cover maintenance costs. You should also bear in mind the possibility of rent control being introduced by the Government, which may cap your rental income. If interest rates were to rise more than a corresponding increase in rental, then that could impact your ability to pay your mortgage.

The more cautious investor might prefer to borrow less. You should aim for a rental income of between 1.3 and 1.5 times the monthly mortgage payments.

Many people are put off buying-to-let by the thought that they will have to spend a lot of time fixing problems such as broken washing machines or dealing with tenants who default on payments.

A good agent can take care of everything, from finding tenants and checking references, to managing an inventory and dealing with unexpected problems like burst pipes (although there is of course a cost for this).

It is recommended that all applicants let the property through a member of the Association of Residential Letting

Agents (ARLA). These agents may provide practical assistance with general property management. Their services typically cost from 10% to 15% of annual rents excluding VAT, which is often taken up front for the full term and so can impact your cash flow initially.

Agents can also advise on tenancy agreements. Most lenders require you to have a six-month, assured shorthold tenancy agreement with your tenants. You may also find it more difficult to arrange finance if you are planning on letting to students, or for more irregular tenancy periods, such as holiday lets or company lets. You may also have difficulties if you are planning on letting to a DSS tenant.

Your home may be repossessed if you do not keep up repayments on your mortgage.