So how can you spot whether a Buy To Let "hotspot" is simmering nicely, or has boiled over and cooling at a rate of knots?

If you know the signs, the hazards can be avoided with confidence.

A building boom, a rash of new developments, may make a town centre look the place to be. And that might well be the case.

The trouble with such developments is that they are all too often conceived, planned, funded and built, in isolation.

The job for the developer is to get the development up and start selling off units as fast as possible to start recouping cash, and encourage other buyers into the development before they sell out.

Fair enough.

Your job as a Buy To Let investor is different, and it starts with not being swayed by the acres of gleaming wood floors and granite kitchen work surfaces, but to take a long, hard look at the numbers; does the development, as a Buy To Let proposition, bearing in mind your deposit, mortgage repayments, and rental income, stack up?

At Property Secrets we always stress the need to do the research.

The myth is that Buy to Let is a game anyone can play and anyone can make money at - it isn’t.

Let's take a look at Glasgow where developers have been super-busy in recent years, property has appreciated at a rate of knots, and Buy To Let investors have piled in.

In a city once known for its tenements and violent street gangs, now rejuvenated as a city of culture and education, luxury new-build, two-bed flats regularly sell for between £200,000 and £250,000.

The problem is that think-alike developers in Glasgow have effectively flooded the market with two-bed rental properties.

By upsetting the supply-demand balance, Buy To Let investors who invested in such properties now find themselves in a weak negotiating position, while tenants are able to bargain, and bargain hard.

The problem for landlords is that rental values of such apartments have slumped, thanks to over-supply, to the point where, for many landlords, they are not able to cover mortgage repayments.

Yields in the city have slumped dramatically, often to under 2%, with many landlords having to subsidise rent shortfalls - as well as facing lengthy void periods if they do not price their rents aggressively with two-bed luxury apartments failing to rent at even £600 a month.

Ironically, it is precisely the old-style one-bed tenements, the sort of property thought too unfashionable to be built, that are renting most easily.

Large-scale developments, such as the recently completed Glasgow Harbour complex with 650 flats have helped overload the market locally, with local estate agents reckoning that up to 80% of such flats have been bought by Buy To Let investors.

So how do you avoid such pitfalls?

Keeping an eye on what developers are up to in the area you are interested in is one way.

As well as looking at the sort of properties being built.

For instance, in Edinburgh some 800 flats are being built at a development at Western Harbour in Leith, and another 250 flats are set to hit the market in the city’s Granton Harbour district by the end of year.

Do the research and make your own assessment - is Edinburgh about to go the same way as some areas of Glasgow?

Check out what is being built too. In recent years around 60% of developments have been two-bed apartments.

So perhaps a one-bed flat, a studio apartment, a three bed maisonette, or a four bed family home might make a sounder investment, catering to smaller, but highly vibrant niches in the rental market?

Or should you run scared and steer clear of BTL?

The answer to that is short: No.

Remember, Buy To Let, if you go carefully, is a sound bet long-term.

Only recently the Council of Mortgage Lenders reported that although 0.63% of buy-to-let loans are in arrears of three months or more, that is still lower than the 0.8% rate of all mortgages, which in turn is the lowest rate for two decades!

And bear in mind that while this has been a snapshot of some of the pitfalls affecting markets North of the Border, wherever you are thinking of investing, the same rules apply: take your time, check out the market, ask advice from local agents, assess demand and local rental levels, and work the numbers.  If it doesn’t stack up, walk away.