The Decent Homes programme is a 10-12-year £40bn government initiative to modernise all the UK's social housing.

CityWest Homes, an arms-length management organisation (ALMO), which spun off from Westminster City Council five years ago, is spending £200m refurbishing the 13,000 tenanted homes it manages for the council in the City of Westminster.

Brian Johnson, who became chief executive three years ago, explains: "We've been making the transition from behaving like part of a local authority to behaving like a small organisation that is more independent, able to grow, change and react quickly and deliver more, which has involved a complete rethink of the attitudes and skills we require. Lots of the executive and senior management team here are not from the public sector, which, on the one hand, is a big benefit because we are not constrained by our knowledge of what has and hasn't been possible in the past. A downside is that we don't know what we don't know."

One of the things Johnson and his team did know three years ago was that they needed outside help to manage the refurbishment of the properties they London Block Management, and that it would be "thoroughly irresponsible" to employ 19 people full-time on what would be a lengthy, but finite project. Johnson is a seasoned and enthusiastic user of interim managers, and employing interim project managers on the Decent Homes programme was, he says, "a no-brainer."

He approached Impact Executives for help, and the consultancy fielded Paul Gatrill, a highly experienced chartered civil engineer and building surveyor, to project manage the modernisation and refurbishment of six 20-storey ugly tower blocks on London's Harrow Road. "The initial costing for the works was £48m, and we told him we couldn't afford any more than £36m, so we set him an unreasonable target before he even started," recalls Johnson.

An additional complication was the fact that CityWest Homes' project management processes were virtually non-existent, admits Johnson.

"But during his career, Paul had actually had a hand in building a high percentage of all the tower blocks in London, which gave us the confidence he could deliver reliably even though we were having to construct the processes around him," he says.

"And he has certainly demonstrated his ability to work in a fairly chaotic environment, which is what I have come to expect from interim managers, who add most of their value by virtue of being overqualified for the roles you put them in."

Gatrill joined CityWest Homes in January 2005 with a blank sheet of paper. "I knew what the budget was and that we had to finish before 2010," he says. "I developed a brief and appointed a team of quantity surveyors, architects, structural engineers and a health and safety consultant. We worked with the team from Wates Living Space, the contractors for the regeneration."

Before long, Gatrill was able to bring forward the completion date of the project, first to April 2009 and then to December 2008, and reduce the overall cost by £1.5m.

"We did actually look at pulling the buildings down and starting again from scratch, but that would have cost twice as much, taken over twice as long and would only have given the buildings a life expectancy of 50 years, compared to the 30 that the refurbishment will provide," he says. "It would also have meant finding temporary accommodation for the residents."

As it is, the modernisation is already causing residents plenty of upheaval, and Gatrill admits that the 'resident consultation' has been the single biggest challenge of the project. "The building is the easy bit; the people aspects are difficult and demanding," he says.

All of his previous project management experience has been in the private sector - hotels, office blocks and so on - and all of it new build. "You get all sorts of design and delivery problems, of course, but those are relatively easy to overcome," he says.

Johnson admits that the organisation has learnt from the experience.

"We were right to bring in some very high-calibre project management skills from outside the sector, but I think we all under-estimated the enormity of the resident consultation challenge, which is very different from typical project management exercises," he says.

"These blocks have had limited investment over the past 20 to 30 years, and residents' experience of makeovers is often from the TV, where people like Carol Smillie turn up in orange boiler suits and transform the place in two days," Johnson continues. "That does not reflect the reality of the kind of upheaval involved in our refurbishments, so managing residents' expectations has been enormously difficult. We have done lots of consultation, which is good, but actually, most people are far more interested in how the work will affect them week-by-week."

Gatrill bears the brunt of residents' frustration. Johnson says: "Paul will get calls on a Sunday morning to say the one remaining lift in a tower block has stopped working - the other one being out of service because it is being replaced. Throughout it all Paul has never lost his spark or passion or his desire to do things differently."

One element of the resident consultation that is exercising Gatrill at the moment is the installation of digital TV. "The buildings are bristling with satellite dishes, and we want to replace them with two big dishes on each roof and then cable down the TV to every household," he explains. "But over half the residents are Arabic speakers, and we need to provide Arabic, Egyptian and Turkish TV stations, among others."

But Gatrill and his team are now half way through the project, and this month the scaffolding and protective netting comes off the outside of one of the buildings, allowing residents to see out of their windows for the first time in months and use their new balconies.

The Decent Homes initiative is just one of many things CityWest Homes has had to get right over the past two years as it adjusts to a more independent life.

"Partly by virtue of our own experience and partly by bringing in different experience we have managed to hit some of the ludicrous time scales and budgets we were faced with," says Johnson. "That gives us real influence on government policy, and we are now rated in the top 2% of similar organisations in the country because of the things that Paul and others like him have helped us deliver. They have played an important role as part of a high-performing team. In particular, Paul's achievement in delivering this project under budget and early is a fantastic achievement."