A revamp costing up to £20m is on the cards at John Lewis's department store at Cheadle Royal to coincide with its 15th anniversary next year.

Maggie Porteous, managing director for the outlet and the chain's Trafford Centre store, said the overhaul would provide more sales space and would be on top of a £2.4m refurbishment of the womenswear department which has recently been completed.

In addition, John Lewis will spend around £250,000 during the remainder of 2010 on upgrades across both branches to create more space for designer clothing and accessories ranges.

News of the investment came as John Lewis announced profits before tax and bonuses of £306.6m for the year to January 30, up 9.7 per cent on the previous 12 months.

Total sales climbed 6.5 per cent in the period to £7.4bn and have surged 13.5 per cent in the first five weeks of this financial year.

The chain's growth means staff will take home a windfall worth 15 per cent of salary.

John Lewis will hand out the equivalent of nearly eight weeks wages to its 70,000 employees – more than 1,600 of whom work across the Cheadle Royal and Trafford Centre stores and its warehouse and distribution centre in Stanley Green, Handforth, Cheshire - after the bonus pot topped expectations at £151.3m.

A new call centre in Didsbury is due to open later this year, employing 250 staff.

Chairman Charlie Mayfield said he was “delighted” that employees would “share fairly in the financial rewards of a successful year”.

Each worker - from the weekend check out assistant to the chairman - receives the same percentage of salary as a bonus.

The average wage at the group is £9.25 per hour, which translates to £11,000 a year as many of its employees work part time, and the average payout will be £2,100.

Waitrose was the group’s star performer last year, with operating profits before property gains up 26.8% to £268.2 million as revenues rose 9% to £4.5 billion.

John Lewis department stores saw sales rise 2.8% last year to £2.9 billion, while operating profits excluding property gains increased 15% to £165.9 million.

The group said the division “emerged powerfully from the recession” and like-for-like sales have accelerated in recent trading, with growth of 14.9% compared with last year’s overall 2.3% increase.

Sales at the Trafford Centre grew by 6.9 per cent last year – the second largest increase across the group - but dipped 1.4 per cent at Cheadle Royal.

Maggie said both stores saw revenues rise during the second half, with demand for TV sets and digiboxes fuelled by the Granada region's digital switchover, while fashion sales were buoyant.

The group expects more challenging trading conditions this year, especially in the second half.

“ The likely withdrawal of monetary stimulus, higher taxes, the possibility of increased interest rates and the implications of public spending cuts make for an uncertain outlook which is likely to impact on consumer confidence,” it said.

But Mr Mayfield said he was upbeat on the prospects for the group.