The State of Trade survey by the Federation of Master Builders (FMB) found the final three months of 2013 saw more firms securing work and predicting that trend would continue.
A composite indicator, combining existing workload, expected workload and enquiries, improved by seven percentage points to a net balance of +4.
That was the first positive balance - where firms expecting better conditions were more than those predicting contraction - since the first quarter of 2008.
Grahame Barn, FMB Scotland director, said: "This survey shows that Scotland's SME building sector is back on track, posting the most positive results in nearly six years."
Separately research from the Scottish Building Federation said almost a third of the public believe investing in infrastructure is the best way to boost Scotland's economy.