Neighbouring primary schools are at loggerheads over expansion plans, which one headteacher says would have a "devastating" impact.
Hounslow Heath Junior School, in Selwyn Close, off Cambridge Road, Hounslow , is expanding from four forms of entry to seven to meet the demand for school places in the borough.
It plans to build a three-storey extension to accommodate the influx of new pupils, which will see numbers there rise from 527 to 840.
But the proposals have not gone down well with neighbouring Hounslow Heath Infant and Nursery School , in Martindale Road, Hounslow, which says on its Facebook page they will "devastate both schools for decades to come".
Kathryn Harper-Quinn, headteacher of the infant school, claims the planned extension is too large and ends just three metres from the boundary of her school.
She is particularly concerned about the impact on her school's "iconic" adobe huts, which have since been funded for other schools by Heathrow.
Expansion plans 'shocking'
"We are surprised that the juniors head expected a positive response to the prospect of an enormous building destroying the green openness of the outdoor learning spaces that currently exist and possibly threatening the stability of our beautiful adobe," said Ms Harper-Quinn...
"I doubt any institution that cared for the wellbeing of its pupils could look at this proposal and think this building on this part of the schools site is anything less than shocking!"
The infant school has already expanded to seven-form entry and the junior school is set to take its first seven-form intake this September.
The junior school is still consulting about its proposed extension, with a final design yet to be submitted to Hounslow Council for planning permission.
Ritu Aulakh, headteacher of the junior school, said it had tried to address the concerns raised by the infants school when drawing up the revised plans, for example by changing from a flat roof to a pitched one.
Junior school headteacher 'disappointed' by opposition
She told getwestlondon she was "very disappointed" by Ms Harper-Quinn's reaction, especially given it had supported the infant school's expansion to seven-form entry.
"We need the extra space and if we were to build a single-storey extension we would use up even more of the play space, which is already 50% below what is recommended," she said.
"The surveyors have looked at other possible locations and have concluded this is the only location possible.
"I'm very disappointed about the manner in which the concerns have been raised by the infants school because we serve the same community... It's been quite divisive."
Ms Aulakh added that it was working under "very challenging circumstances" as it had not inherited land for its expansion, unlike the infants school which converted existing council buildings into new classrooms.
'Only feasible location on which to build'
Councillor Tom Bruce, Hounslow Council 's education chief, said the planned building would provide 14 new classrooms, toilets, four group rooms, a library and an ICT suite.
He told getwestlondon the headteachers of both schools had been given the opportunity to shape the plans but the west side was the only "feasible location" on which to build, with other options having an "unacceptable" impact on the existing junior school.
"With the junior school, we need to provide extra classrooms for the additional three forms of entry which will be feeding through from the infant school, but we need to do this within the existing school grounds as we don't have any neighbouring buildings which can be used," he said.
"Meetings were held with parents, school staff and neighbouring residents the chance to give them the chance to view plans before they are submitted, and to offer their comments.
Once final plans have been submitted to the council’s planning department, all interested parties will be invited to submit formal comments as party of the statutory planning consultation."
Should planning permission be granted, work would begin this summer and the three-storey extension is due to be ready in autumn 2018, with the full expansion project scheduled for completion by autumn 2019.
