As reported, city councillors unanimously agreed in March to proposals for a multi-storey complex at the hospital.
Under the scheme, which will be built on the northern side of the existing north car park, the site is set to connect to a new 72-bed ward - that was given planning permission in December - by a link bridge at first floor level.
However, it has since been ruled that a straight link bridge would not ‘marry up’ to the correct location on the new ward.
As part of the new application, a statement said: ‘Accordingly, a longer link bridge is now needed, with a turn to provide a longer distance at a gentler slope which matches the levels of each building.
‘As this step involves building over a small, landscaped area upon which two trees were previously proposed, these trees can no longer be planted here.
‘To compensate for this tree loss, three additional trees are proposed to the west of the multi-storey car park to ensure that there is a net increase in tree planting across the site.’
However, the project will still provide a total of 541 car parking spaces and six motorcycle spaces as originally proposed.
It comes as work to create the new neighbouring 72-bed ward began in March. And plans for a new £58m emergency department at QA are also in the pipeline.
A spokesman for Portsmouth Hospitals University NHS Trust, said: ‘Our programme of work to develop the Queen Alexandra Hospital site will provide much enhanced facilities for our patients, their families and our colleagues.
‘These revised plans will also see an increase in landscaping and planting on the western boundary of the site – part of our commitment to creating more green space for people who need to visit the hospital.’
The amended plans will be considered for approval either by a Portsmouth City Council officer or its planning committee at a future date.