The loan fund was put in place at the end of last year to unlock stalled sites with planning permission in the hope of spurring more than 15,000 homes to be built.
Shapps has revealed that more than £100m is still left in the loan pot, which could see an extra 2,000 homes built.
The Get Britain Building fund has already provided a boost to developments in places including Ashford and Bath, where work has now restarted on 181 new homes.
Previously, builders bidding for cash had to have plans for at least 25 homes on their sites. Now, to help smaller firms bid for funding the minister has lowered the bar to 15 homes.
Shapps said:"By spreading the net wider and boosting the number of eligible sites we can offer more help to builders both large and small.
"We saw huge appetite last time for this funding but some developers later found they could build without the fund.
“We need to be sure every single pound of taxpayers' money works as hard as it can so we can get as many homes as possible out of Get Britain Building. That is why I'm inviting further bids."
The fund is administered by the Homes and Communities Agency, the body responsible for assessing applications.
Expressions of interest must be submitted by noon on 25 July 2012.
Mike Leonard, director of the Modern Masonry Alliance commented, "This is good news for SME's who should have been the priority. That said the bank's attitude to lending to smaller building companies is strangling the market and this policy must end.
"What UK PLC needs now is the big ideas to turn around our economy and create jobs.
"25,000 additional public rented homes is what is needed. We have the demand, skills, capacity and will. All we need is the cash to make it happen.
"Time to stop playing on the fringe Mr Cameron, let's work together to really Get Britain Building."