Case Study // Bexley Mental Hospital

Location & History 

Bexley Mental Hospital was situated on Darenth Park and was one of the largest asylums of its kind. Declining patient numbers and increasing maintenance costs resulted in the eventual sale and redevelopment of the existing site.

The site itself spanned 164 acres and contained 18 wards, 6 acute admission wards and a further 32 medium and long stay wards within its compound.

The asylum was constructed to accommodate an all-encompassing self-contained community which homed livestock, a chapel and an underground central heating system which was powered by a steam operated boiler house.

As with other mental hospitals in the process of becoming redundant, Bexley Hospital with its 1,000 beds became extremely difficult and costly to maintain and was closed in 2001. After a year of vacancy, NHS decided to procure the demolition of the Hospital and appointed Erith to aid the redevelopment package.


Erith’s activities during the course of the works included the following:

  • Isolation/Disconnection of all live services to the building
  • Decommissioning of Boiler/Steam Heating System
  • Bulk Asbestos Removal
  • Demolition of existing structures down to ground slab level
  • Break out all hard standings and foundations down to a depth of 1.5m
  • Material management in the form of on-site segregating, screening, crushing and backfilling voids left by demolition of structure footprints

After extensive ground investigations, it was identified that an underground steam heating system had been constructed beneath the site compound which provided power to the asylum structures within the site boundary.

Due to the historic make-up of the site, surveys identified asbestos had been utilised as a building material in lining the underground ducts and gaskets. This process required Erith’s demolition and asbestos removal divisions to work concurrently to ensure we met with the NHS tight programme durations.

A previous contractor demolished a redundant gas holder on site which provided gas to structures within the hospitals compound and had left the ground contaminated requiring remediation. Erith utilised their in-house remediation division to remediate the contaminates which remained in-situ from the former gas holder.


Project Goals

  • No reportable accidents or incidents recorded throughout the life of the contract
  • Project completed within the desired contract programme