Emma, 23, works for the local wildlife trust and Matt, 24, is in construction. They moved to Cornwall because rents in their home town, Reading, were too expensive.

They have lived everywhere from a flat above a pizza parlour to a caravan. The couple, who jointly bring home �20,000 a year, are forced to move on every summer when landlords hike up the rent.

When the sale on a house they were buying fell through after three months, they discovered prices had soared still further. Having borrowed �5,000 from Emma's parents, the pair seem no nearer to affording a home.

The demand for holiday homes in Cornwall means vendors can ask extortionate prices.

"You really just want to scream at them: 'Please, just stop! Give us a break!'" says Emma.

Rob Clifford Mortgage Force

Emma & Matt's hopes of buying a house in Perranporth at around �113,000 are probably a little over ambitious.

Although they have a �5,000 deposit from Emma's parents, this does not give them limitless purchasing power.

We have two routes to consider:

1. Lenders who use standard income multipliers.

2. Lenders who calculate borrowing based on an affordability formula.

Choosing a product and lender

Using income multipliers and subject to credit scoring, the best Emma and Matt can probably hope for is around �70,000 (3.5 times their joint salaries). This will leave them significantly short of buying even a flat in Perranporth - where the average price of such a property is �100,000.

Using a lender who adopts the affordability route, however, can change the picture dramatically.

With a capital and interest repayment mortgage, the longer the term, the lower the repayments become.

Now, whilst we are not advocating mortgages over very long periods of time, the following route will solve Emma and Matt's issues today at least.

With a �5,000 deposit, we can source a mortgage of up to �97,000. The term for this level of borrowing would need to be 35 years, and a 40 year term may even increase that figure again.

We think this demonstrates how vastly different people's prospects can be depending on the lender they use.

Whilst this still will not allow Emma and Matt to buy a three-bed house in Cornwall which is typically priced at �120,000, it does put the flat at �100,000 within reach.

This may not be their ideal choice, but they are governed, to some degree, by the market conditions. Maybe, with some extra deposit, they could put themselves in a position where they could at least make a reasonable offer on a house in the hope the vendor decides to accept.

Warnings

Whilst we have shown it is possible for Emma and Matt to buy in Cornwall, it is quite clear that they will have an extremely heavy reliance on both their incomes.

They need to make absolutely sure that they have adequate protection against sickness (long and short term), redundancy, etc. It would be impossible for them to maintain their commitments on one income.

Their monthly expenditure will have to be carefully managed if they are to maintain a reasonable lifestyle and not over commit themselves.

We should also point out that the mortgage available would be subject to a credit score and that the very fact they have moved six times in 18 months may have had an adverse effect on their credit rating.

How the government could help

Changes in legislation could help first-time buyers like Emma and Matt in a number of ways: