Around a fifth of FTBs plan to spend an average of £5,000 on cars, holidays and other luxuries before a mortgage, the Alliance & Leicester found, yet this could push them into debt.
“Buying your first home can be a costly process and first time buyers need to be practical about what they can and cannot afford,” warned Richard Taylor, head of mortgages at the building society.
News of a financial blow-out stands in contrast to the struggle of many FTBs to get onto the housing ladder, many of whom have had to rely on parents or high-value loans to get a home.
While Mr Taylor said he could understand why people would wish to spend money before taking on the financial commitment of a mortgage, he warned against it.
Instead, Mr Taylor said that with a proper debt management plan FTBs can enjoy their new home without it affecting their normal life too much.