When asked to say what concerned them most about the prospects for the mortgage market in a year ahead, a panel of industry participants said changes to regulatory policy settings might put additional pressure on capital requirements and force lenders to put up interest rates.Deloitte has published its Australian Mortgage Report 2016, which paints a picture of a market with good growth prospects, despite being buffeted by regulatory headwinds. The report included the findings of an industry roundtable.Last October and November banks put up mortgage rates by between 15 basis points and 20 bps. This move was led by the big banks, which had raised equity during the year to strengthen their capital positions in line with regulatory requirements.There is more on the drawing board, including a higher risk weighting for loans that rely on a rental income stream to service the loan.Macquarie Bank head of personal banking Frank Gains said: "We would expect that the re-pricing cycle for mortgages that started some six months ago across the industry will continue."Earlier this year the Basel Committee on Banking Supervision said it planned to simplify the way banks assess the riskiness of their assets for regulatory capital purposes.The Committee's view is that the wide discretion given to banks under earlier versions of the Basel rules has created variability, which makes it hard to compare capital ratios and capital adequacy.Pepper Group co-chief executive Patrick Tuttle said: "My concern is that if the banks can't be trusted to do their own sophisticated internal modelling the regulators will dumb the market down to the lowest common denominator, which will drive inefficiencies in the market and reduce competition."Deloitte financial services partner Kevin Nixon said the round of mortgage risk weight changes that were announced last year added about 80 bps to 100 bps to capital requirements.Nixon said: "The Government has asked APRA to take additional steps in 2016 towards the 'unquestionably strong' goal, so in addition to changing how mortgages get calculated, there is potential for further pressure for banks to hold more capital overall."The panel's other concerns were the stifling effect of the regulatory focus in investor lending, the risk of inappropriate lending tinting the industry, house prices falling and unemployment rising.