Q I own a flat which is now not worth what I paid for it. It is currently for sale but I am giving serious consideration to going down the let-to-buy route. I would let my flat and buy another for me to live in – if I can afford it.

I am a 46-year-old, single female in full-time work and my annual salary before tax is 26,000. My property is a studio in the heart of the West End of Glasgow. The area is full of nice bars, restaurants, delis and so on and a popular choice for people who work or study at Glasgow University and local hospitals.

My flat has been for sale for a few weeks and has been valued at 110,000. I paid 126,000 for it in 2007 and have recently been offered 106,000 by a prospective buyer. The outstanding mortgage is only 54,000 and the monthly payments are around 400 on a repayment mortgage. If I were to let the flat, I could hopefully get a buy-to-let mortgage with interest-only payments of around 160 a month. The monthly income from rental would be around 400 per month. I would need a contingency fund to cover maintenance costs and buildings insurance.

If I let my property, I would have a budget of around 125,000 to buy another property for me to live in. If I sell I would have a bigger budget and could buy a property at around 150,000. The dilemma is whether it would be wiser to keep my current flat as an investment, or cut loose and start fresh. GM

A In answering your question, it would be easy just to look at the numbers but I have been influenced by another reader who was in a similar sort of situation to you.

In 2006, she bought a studio flat in Dewsbury for 70,000. In 2007, she moved to London for work and because the studio flat was valued at 57,000, she thought she should therefore hang on and try and rent it as she didn't have the money to be able to pay the mortgage shortfall that she would have faced had she sold the property.

In her words: The result has been over five years of stress and frustration, finding and managing tenants and the flat, as well as finding the extra money to cover the shortfall in rent (which has gone down over the time period) and the management fees for the building (which have also gone down but at their peak were nigh on 1,000 a year). In the meantime I have been in rented accommodation . Faced with this stress, she voluntarily surrendered the property and handed the keys to her lender and is now waiting to hear what she owes as the property is still worth less than the outstanding mortgage.

Although you are not in the position of owning a property that is worth less than your mortgage and so are not being cornered into letting your current flat, before you even think about keeping it, you need to ask yourself if you are cut out to be a landlord with all the responsibilities – and possible stresses – that can bring.

This fundamental question also applies to other readers who have asked whether they should keep their current property to let-to-buy another one, or even, as in another case, buy a seafront property from a family member as an investment to do up and let out while living in rented accommodation themselves. Although the return on investment may be higher than putting money in a savings account, buying to let also requires more effort – or a lower return if you decide to use a letting agent to manage the property.

So before looking at whether the figures add up, you need to be convinced that you can make a go of being a landlord. Assuming you think you can, the question then is, can you afford to? If you converted your current 54,000 mortgage to a let-to-buy mortgage, you are right that monthly interest-only payments could be around 160, assuming you can get an interest rate of 3.5%, which is on the low side for this type of mortgage.

Simply converting your current mortgage would also raise no cash to put towards the purchase of your new home. To do that, you would need to increase the size of the mortgage, possibly to 75% of your flat's current 106,000 value (the standard maximum on let-to-buy loans). That would mean a 79,500 mortgage which, after paying off your 54,000 residential mortgage, would leave you with 25,500 in cash to put down as a deposit on a new home. But with that size of mortgage, the monthly interest-only payments would go up to just over 230 (assuming a rate of 3.5%), or nearly 300 assuming a slightly more realistic 4.5% mortgage interest rate. On these figures, I would say that keeping the flat on as a rental property is a bit of a squeeze, especially as you anticipate only 400 a month in rent.

If you simply cut lose and started afresh you would have none of the hassle of being a landlord and 52,000 in cash to put towards buying your next home.

Muddled about mortgages? Concerned about conveyancing? Email your homebuying and borrowing worries to Virginia Wallis at virginia.wallis.freelance@theguardian.com