School trustees say they looked at nearly 200 sites before settling on a former playing field as the preferred spot for their new home.
Plans for Nishkam School West London's permanent building at the old Conquest Club site, in Osterley, went on public display on Wednesday (May 20), following weeks of controversy.
The Education Funding Agency (EFA), which finances new schools, had angered some local residents by purchasing the land, sandwiched between Syon Lane and Wood Lane, and erecting hoardings - since removed - beyond the boundaries without any consultation.
At a public exhibition held at Osterley Park Hotel in Great West Road, Brinder Singh Mahon, chairman of Nishkam School Trust, said: "A massive number of extra secondary school places are needed in Hounslow by 2019. The process of finding a site has taken over 18 months, during which time we looked at 197 sites.
"The land is currently in a state and is prone to fly-tipping. We want to regenerate it, while maintaining all the woodland. We're not planning to cut down any trees."
The plot in question is protected Metropolitan Open Land, meaning the school and the EFA would have to demonstrate special circumstances to get planning permission.
They say the demand for new secondary school places and the lack of suitable alternative sites meet those criteria.
But opponents have questioned why the land was not included as a possible school site in Hounslow Council's Local Plan - a blueprint for future development across the borough - whereas several brownfield sites, which have previously been developed, were.
Neighbouring residents, who fear the impact on traffic as well as the loss of green space, have demanded to see a full list of other sites which were eventually rejected.
One critic, who asked not to be named, described the site as "the easy option" and claimed it could open the floodgates for development in one of the borough's few remaining green havens.
Another said surrounding roads were already so clogged in the mornings it took him 20 minutes to drive a few hundred metres, and the extra traffic generated by the school would only make things worse.
Trustees say 86% of pupils currently come from within the borough and many would be able to access the new site by public transport.
They are considering running a shuttle bus from Osterley tube station and using satellite car parks, from which children can walk, to ease congestion at the site itself.
Parents and grandparents of existing pupils broadly welcomed the plans but shared the general concerns about traffic.
They praised the school, with one father saying he had never known his children to be so keen to go to class, and claimed a number of parents already had car sharing arrangements in place.
The proposed building would be situated in the southern half of the site and would be two to three storeys. There would be 80 car parking spaces along the driveway in Syon Lane and a pedestrian entrance in Wood Lane.
The architect BAM says it has been designed to keep out noise from aircraft and from traffic on the nearby A4.
Should the new school building get the go-ahead it would open in September 2017 and would eventually accommodate 1,400 pupils.
Nishkam is currently based in an old office block in Isleworth, which it will soon outgrow as it continues to expand each year. A planning application is expected some time in June.
A second public exhibition will be held at Osterley Park Hotel, 764 Great West Road, Osterley, on Saturday (May 23), from 10.30am-2pm.