Builders working on a new £3.2m visitor centre on Skomer Island are on schedule to complete the first stage of the project by November.
Materials have been arriving on the island by barge
The 10 workers have been living on the island off Pembrokeshire, alongside thousands of sea birds since April.
They have been renovating an old farmhouse into overnight accommodation for visitors.
The next phase will see new quarters for the resident warden, a laboratory and study rooms for researchers.
When work is finished, an estimated 20,000 people a year are expected to visit the centre.
Paul Evans, who is head of the work for Swansea-based Dawnus Construction, said the isolated nature of the project had caused difficulties.
The builders are renovating an old barn on the island
"The obvious one is the logistics for getting the materials and the men across to the island - it is very weather dependent," he said.
He also said spending four nights a week on the island had been "difficult".
"It was a little bit exciting for some of them when they first started - I think the excitement is wearing off a little bit at the moment.
"On a Thursday they have a quiz night, they play a bit of darts, they have TVs and videos - they have good camaraderie."
Peace and quiet
Warden Juan Brown said an old barn was being reroofed and renovated, thanks to money from the Heritage Lottery Fund, the Countryside Council for Wales and the Tubney Trust.
Workers are trying not to bring any predators across on the barge
"There will be overnight accommodation which will enable people to enjoy the biggest spectacle that Skomer is famous for, the Manx Shearwaters, which only become active on the island during nightfall.
"There will also be a new visitor centre which will enable the day visitors to enjoy the island more and also understand more about what the island is important for."
He added that the work had not upset summer visitors.
"You can easily get out of ear range of the building works, so people have actually come onto the island and still enjoyed the peace and quiet and the wildlife."
Skomer island is a national nature reserve, a site of special scientific interest and a special protection area under European law, and is designated as one of only three marine nature reserves in the UK.
It has an estimated population of 165,000 pairs of Manx Shearwaters, approximately 6,000 pairs of puffins, as well as guillemots, razorbills and gulls.