With the HST looming, some business owners say they're scrambling to fill last minute orders, but worry what will happen once the new tax comes into effect next week.

Vancouver resident Georgia Lapointe was getting new windows installed on Friday.

"We had planned on doing windows -- that is something we thought about -- but it got pushed ahead because of the HST," she told CTV News, estimating she'll save about $3,500 by getting the work done early.

Her contractor, West Coast Windows, has been booked solid for all of June.

"All of a sudden people jumped on the bandwagon and wanted to be pre-HST," the company's president Bryan Hayes said.

But when the tax takes effect on Thursday, he expects a considerable drop in business.

"We're offering to pay the (extra) seven per cent for customers," Hayes said.

"Hopefully, that will work to give us some activity. Otherwise, it's going to be a struggle to keep the plant busy through July and August."

And it's not just window companies promising to swallow the tax for their customers.

Ken Mayhew, president of Penfolds Roofing, said that his company will be doing the same.

"We've been offering all kinds of incentives and ultimately picking up what we call the HST difference, so as a company it's added to our costs," he said.

Both companies say the harmonized sales tax will save them money on materials, and they promise they'll pass those savings along to consumers.

But more than half of their costs are for labour, and that means the net difference for consumers will be an increase in price.

"We're not going to save seven per cent with the input tax credits for HST. We think maybe a 1.5 or 2-per-cent maximum difference, so the customer's going to pay for it ultimately," Hayes said.

Mayhew predicted the average price for roofing services will go up by about five per cent.

With a report from CTV British Columbia's Shannon Paterson