Britain's universities are gearing up for a cut-throat battle to attract and recruit students – by making more unconditional offers of places, using sophisticated marketing, and building prestigious campus developments – spurred by government changes that are transforming university admissions policies.

As sixth-formers prepare to open their A-level results on Thursday, university admissions officers are predicting that this year's clearing round – when students who do not attain their expected grades go hunting for places – could be the last of its type.

The government has raised the limit on total undergraduate numbers by 30,000 for September 2014 – as a halfway house towards removing the limit entirely in 2015, when universities will, in theory, be able to admit as many students as they can handle.

University admissions officers have told the Guardian they are making more unconditional offers to students, in order to avoid the gamble of clearing, and the danger of being left empty-handed.

"The game has changed. It feels like the cap is already off because I don't feel like there's another 30,000 capable students out there," said Gary Davies, director of recruitment at the University of Roehampton. "In the last few years we've had change after change, but the biggest one is that clearing in a sense has gone. Most institutions are confirming more students than in the past. We've seen a drop-off in those first frenetic couple of days. Clearing is less a second chance than a late applicant process."

Ian Denning, recruitment and admissions officer at Coventry University, said there was now "a lot less" of a focus on A-level results day. "In line with other universities, we have made more unconditional offers this year. Our strategy has been to maximise the number of students coming through the main application cycle rather than relying on clearing. We don't want people to decide on Coventry based on a couple of days in August."

The changes leave university managements with higher levels of uncertainty, as many go ahead with expensive building projects secured by the income from the £9,000 tuition fees they receive from each full-time undergraduate.

"The whole marketplace is becoming more competitive. It is very confusing for students and their advisers and they often do not understand the situation with student numbers fully," said a spokeswoman for Nottingham University, which also expects to have fewer places available through clearing this year.

"There is going to be more competition as institutions can take as many students as they want to from next year. But we think we can compete with the best in the UK," said Roderick Smith, director of admissions at the University of Birmingham, a member of the Russell Group of leading research institutions. "We have a continuous capital investment programme going on. We're building new halls of residences, a new library and a new 50m swimming pool. But we would have done that anyway."

Even members of the Russell Group have £9bn of capital investment in the pipeline to improve facilities and attract students, according to a recent report.

"We are seeing this in our discussions with universities as they increasingly focus on investment in teaching, learning and research, to prepare for tougher competition for students and as students' expectations continue to rise," said Julie Mercer, lead partner for education consulting at Deloitte.

"However, university growth is more likely to be curtailed by physical constraints, such as being able to recruit enough quality academics to support the student population and the extent to which they can invest in and build facilities to teach and house more students."

The most eye-catching case is that of Swansea University, involving the creation of an entirely new campus over 65 acres of a former petrochemicals site. Known as the Bay campus, it will open next year and house 900 students as well as the university's college of engineering and school of management.

"This will allow us to expand our intake as there is no room for expansion on our current campus," said Jacqui Bowen of Swansea. "This is a £450m development and no other university is currently doing anything comparable."

The university says its applications are up 25% this year: "We have had a very strong marketing campaign over the last couple of years and a big part of that is attracting students west from England."

Liverpool University – another Russell Group member – is in the middle of a £230m investment in new accommodation, including Crown Place, due to open this year with 1,259 en suite bedrooms, near the university's 24-hour library and sports centre with swimming pool.

In Northern Ireland, Paul Quinn, recruitment manager at the University of Ulster, said: "We typically have around 5,000 places available and last year we had 33,000 applications just from Northern Irish students. We still have a cap set by the Northern Ireland assembly on Northern Irish students, but not on British students. We still want to attract British students. Applications from England went up 16% last year. We don't have the same cut-throat competitive situation as the universities where the cap has been lifted.

"We are a unique choice – our fees for British students are less, £6,000 rather than £9,000 and that's a good thing. The proximity of Northern Ireland, post-Troubles, means we are a really good experience for students."

The campus construction boom will continue as universities nervously await their brave new, uncapped, world.