Northern Ireland's four main banks are asking for higher deposits from home buyers in response to the economic impact of coronavirus.
anks and other lenders are offering lower 'loan to value' (LTV) deals - partly in a more cautious approach to guard against a fall in house prices.
In a move to stimulate the UK market, Chancellor Rishi Sunak is tipped to announce a stamp duty holiday in a summer update on Wednesday. Speculation suggests that he would move the lower threshold from £125,000 to somewhere between £300,000 and £500,000.
AIB, Bank of Ireland and Danske Bank confirmed that they are now limiting deals to a maximum of 85% of the value of a home - meaning buyers have to come up with a 15% deposit.
Ulster Bank said it is restricting its mortgage offers to 80% "but continually keeps this under review".
AIB said: "In order to protect our customers, the bank and the economy in this pandemic, and in line with house price and economic uncertainty, we have adjusted our LTV limits."
A Danske Bank spokesman said: "With the housing market now re-opened, we have re-introduced mortgage borrowing up to 85% loan-to-value."
Bank of Ireland UK said it is lending up to 85% LTV.
Progressive Building Society, which launched a 95% product in January for first-time buyers, said it is no longer offering 90% or 95% deals. A spokeswoman said it "remains committed to responsible lending and will continue to monitor its product range across all LTV bandings".
"It will closely monitor the mortgage market to ensure it lends prudently while ensuring that it supports the resurgence of the local housing market."
Housebuilder James Hagan of Hagan Homes said its buyers were not being offered suitable deals. He added: "We have really strong bookings and interest in the properties but with no 90% mortgages available from banks and mortgage providers, this means our purchasers need to have bigger deposits."
Nationwide Building Society also confirmed it has a maximum LTV of 85%.
Last month Nationwide said: "As a responsible lender, Nationwide needs to ensure borrowers can afford mortgage payments and are, as much as possible, protected against the potential for negative equity, should house prices decrease."
A spokeswoman for personal finance website Moneyfacts.co.uk said the number of higher-loan-to value deals had fallen after huge demand for the products led lenders to pull back.
"There has been an overwhelming level of demand from borrowers seeking products in these sectors, leading to some lenders who had recently brought back products for borrowers with a 5% to 10% deposit or equity needing to quickly withdraw those to ensure that their workload and service levels could be managed, and so that they are able to continue to support their existing customers," she said. "The potential for negative equity issues should house prices slump is now also a concern and is a risk that lenders will of course be keen to mitigate."
Lenders were also aware that current borrowers may face future financial difficulties, she added.
The housing market here reopened last month after a three-month shutdown.
One mortgage advisor said there was evidence of some house price growth since the reopening.
Eoin O'Hagan, director of CPS Financial, part of estate agency CPS, said: "The mortgage market is extremely buoyant due to the pent up demand which took place during lockdown, interest rates are at an all-time low and confidence has returned to the property market with both buyers and sellers eager to resume transactions."
But he said Northern Ireland had long been at a disadvantage compared to the rest of the UK, as there is a smaller pool of potential lenders.
Mr O'Hagan said there was evidence of 90% products returning this month.
He added: "With the property market experiencing high transaction levels and in most cases even above pricing levels pre-Covid-19, the mortgage market while slow to react is starting to show signs of higher LTV lending such as 90% mortgages returning during July.
"Demand currently outstrips supply for the 90%-95% mortgage product, with some lenders having to withdraw these products due to the unprecedented high levels of applications."