Kingspan Insulation said the redundancies at its Pembridge factory were "unavoidable" to minimise the impact of a noticeable decline in trade during 2008.
In a statement, the company said every possible step would be taken to minimise the number of job cuts, including full dialogue and consultation with trade unions.
A spokesman for Kingspan, which expects market conditions to recover within the next 18-24 months, said: "The current economic downturn is having a wide-ranging effect on business, and has hit the housing industry particularly hard.
"At this point in time the number of new houses being built is down by around 50 per cent from the start of the year, and it is predicted that next year will see a 20 per cent drop.
"Although in general terms the business is strong, additional pressures in terms of rising costs have meant that steps must be taken to manage and minimise the impact of the current market trend."