Brick and Stone has decided to increase its stocks of the former by two thirds in response to a marked increase in demand from firms in the building trade.
"We have witnessed a real increase in momentum in the construction sector and the new facility will provide us with the means to bring our business to the next level," said managing director Mark Findlay.
The privately owned company is targeting a 20% increase in turnover this year, to around £1.3 million from £1.1m in the last financial year.
Its decision to expand provides the latest sign that the construction sector in Scotland is starting to pick up, following the long downturn triggered by the credit crunch, which started in 2007.
Broxburn-based Brick and Stone said it had weathered a "stormy few years" in the sector, in which activity levels slumped after banks turned off the supply of cheap credit that had fuelled the boom in the first years of the millenium.
The company used its expertise in working with specialist materials such as reclaimed, or reused, stone to win work from public bodies to help offset the fall in private sector activity.
It has provided stone and cobbles for restoration work at Edinburgh Castle and reclaimed granite kerbs for Sumburgh Lighthouse in Shetland.
The company also supplied stone for the Water of Leith flood prevention scheme in the Stockbridge area of Edinburgh.
Bank of Scotland and Lloyds' Commercial Finance, owned by Lloyds banking Group, are providing expansion funding.
The company previously banked with Royal Bank of Scotland.
Brick and Stone plans to increase its stocks to include 500,000 bricks, from 300,000 currently.
It holds more than 1000 tonnes of stone. The volume of stock is partly dependent on the availabilty of supplies that can be reclaimed from old buildings and the like.
Donald Lee, Relationship Manager at Bank of Scotland, said wholesalers and suppliers relied on a healthy supply of stock and financial support was vital to ensure demand was met.