Plans for a new Frimley Park Hospital have reached a “major milestone”, according to Frimley Health NHS Foundation Trust, but questions still remain over where the new hospital will be built.

The NHS Trust has been searching for a new site after concerns were raised about the longevity of reinforced autoclaved aerated concrete (RAAC), which makes up the majority of the current hospital buildings.

Frimley Health NHS Foundation Trust says it has now reached a “major milestone” in its plans for a new Frimley Park Hospital after confirming its Strategic Outline Case (SOC) has been completed and submitted to the national New Hospital Programme.

The Trust has not yet announced its preferred location, citing commercial confidentiality, but said it will confirm the site as soon as it is permitted to do so. It stressed that identifying a preferred site does not amount to a final decision. A full statutory planning process, alongside a major programme of public consultation and engagement, will follow. According to its targeted timeline, this would not see construction start until 2028 to 2029.

The SOC outlines the Trust’s plans for replacing the ageing hospital, which it says is unsuitable because RAAC makes up about 65 per cent of the concrete planks in the building.

The document also sets out what services the new hospital will provide, how it will improve patient care and how it will support wider NHS reforms into the 2030s. The Trust said the project is “about more than just a building”, describing it as a system-wide transformation that will modernise care across all its sites, including Heatherwood Hospital in Ascot and the existing Frimley Park campus.

A key part of the work so far has been the long-running search for a suitable site. Nearly 20 locations, each more than 20 acres and within five miles of Frimley Park, were assessed in what the Trust described as a “detailed and thorough process”.

Public suggestions, along with proposals from councillors and MPs, were also evaluated. Staff and residents were asked what they wanted from a new hospital, and this feedback shaped the criteria used in assessing potential sites.

The Trust said the new hospital will be built to “Hospital 2.0 standards”, with digital infrastructure, automation and smart energy systems designed to reduce costs and improve patient safety. It added that it will use modern methods of construction, meaning much of the structure will be manufactured off-site and assembled quickly and quietly, helping to reduce disruption and waste.

Plans outlined in the SOC also include additional theatres and recovery space at Heatherwood Hospital, refurbishment of parts of the existing Frimley Park site for community and outpatient services, and further investment in technology and modern facilities across all locations. The programme will also examine how transport links can be improved and how unnecessary journeys to hospital might be reduced.

Work now moves to the next stage as the Trust prepares an Outline Business Case setting out designs, operational models and costs, followed by a Full Business Case covering contractual arrangements. The Trust said it remains on track for construction to begin between 2028 and 2029.