Sir Ian said MPs' odd hours were behind many expenses
MPs could do away with many of their expenses if they worked office hours, says the man overhauling the system.
In a speech, Sir Ian Kennedy said the Commons "chooses to work its own idiosyncratic hours" - which in turn led to claims for taxis and hotels.
He also said there was a strong case for regulating Lords' expenses along the same lines as the new MPs' system.
He spoke as peers approved changes they say will make their expenses more "clear, concise and comprehensive".
Sir Ian heads up the Independent Parliamentary Standards Authority which is considering which expenses reforms to bring in for the next Parliament - following the damaging MPs' expenses scandal.
In a speech to the Institute for Public Policy Research on Monday, Sir Ian said MPs had argued they needed to claim for taxis or overnight accommodation because of the "difficulties and even dangers" of leaving after a 10.30pm vote. Others argued they had to claim for food if they were working at the Commons until late into the evening.
"This call for financial support only arises because the House of Commons chooses to work its own idiosyncratic hours," he said.
"To put it clearly, ways of working engender calls for expenses which translate as a charge on the public purse. Ways of working, therefore, become directly a matter of value for money.
"Starting and ending the working day when most others do would largely make a number of problems go away. And it would save a lot of money."
Sir Ian also said the case for independent regulation of expenses "should not arbitrarily stop at the door of one House of Parliament. If its time has come, it has come for Parliament as a whole".
Sir Ian's expenses authority will currently only cover MPs - not peers, whose expenses have also come under fire.
Earlier this month the Director of Public Prosecutions Keir Starmer included a reference to the lack of definition of what constitutes a main residence in House of Lords rules, when announcing his decision not to prosecute a Labour peer over expenses.
Peers who claim their main residence is outside London are entitled to claim £174-a-night overnight allowance. Baroness Uddin had been accused of claiming a rarely-used flat in Kent was her main home, so she could claim the allowance.
On Monday peers voted for a new definition of "principal residence" for expenses purposes. They will have to sign a declaration "stating the location of their principal residence, and giving confirmation that it is outside greater London".
The declaration would "include a statement of where members spend most of their time when the House is not sitting (including weekends), and in particular where they spend most nights".
Those claiming overnight allowances will also have to supply documentation "to verify that their principal residence is outside greater London". There would also be internal and external audits.
The head of Lords' administration, chairman of committees Lord Brabazon said it would be "a significant step forward for the House, following a difficult period".
He said: "The new and improved definition does not constitute any criticism whatever, implied or explicit, of those members who have legitimately claimed allowances under the current scheme".
Lords Leader Baroness Royall of Blaisdon, for the government, said the new rules would be "clear, concise and comprehensive" and they were welcomed by the Conservative and Lib Dem front benches.
But Lib Dem peer Baroness Williams pointed out that there was nothing in the current rules to stop her visiting her allotment once a month and claiming it was her main home.