Artist’s impression of new Medical Education Centre. Photograph: Islington Council.

A temporary structure to replace the Waterlow Building, a former mental health inpatient centre which has stood empty for the past 15 years, won planning approval last night.

The new modular building will last only five years and will house the Whittington Hospital’s training centre, after which it will be dismantled to make way for a new NHS ‘masterplan’.

The proposals are part of a wider relocation of health services known as Project Oriel, which includes Moorfields Eye Hospital’s move to St Pancras.

Councillors expressed concern at the planning committee meeting over the temporary nature of the planned building and the fact that they had not yet had sight of any masterplan.

Cllr Tricia Clarke (Lab, St George’s) said: “I really question the need for building a temporary building. It doesn’t sound sustainable to me.”

Cllr John Woolf (Lab, Canonbury) added: “If it’s torn down after five years and we don’t know what the masterplan would be, would we be approving something on a temporary basis and then we’d be in a situation with an empty space for we don’t know how many years?”

Councillors seemed persuaded on balance that the risks of such an outcome were not great, with Cllr Klute saying the committee should “take on trust” that the masterplan was on its way.

Council officers assured the meeting that the NHS is engaging with the Town Hall on the masterplan, though conversations are at an “early stage”.

The facility will house a centre for medical education, demonstration and meeting spaces in a purpose-built building.

Approval was granted to demolish the existing Waterlow building back in July.

The temporary training centre that will take its place will boast lecture halls, meeting rooms, and a medical theatre simulation suite, all in a purposebuilt modular design, or as Cllr Martin Klute (Lab, St Peter’s), chair of the planning committee, described it: “Rooms off the back of a lorry.”

Cllr Dave Poyser (Lab, Hillrise), said: “I’m minded to support the application. They are excellent members of the community. I accept the fact that the NHS is a massive organisation, it’s part of a masterplan and they’re doing their best to fit in with Project Oriel.”