Abbot’s Hill School


Abbot’s Hill School, based in Hemel Hempstead, is an independent boarding school for girls from Nursery to GCSE. Established in 1912 with the aim to create a supportive and caring environment, based on a Christian ethos. As a result, all members of the community encourage qualities of compassion, integrity, tolerance, and a sense of responsibility.


The Abbot’s Hill School project was part of a campus-wide development. To improve and develop the nursery and prep school facilities. The existing campus development was part of their action to provide an excellent education for all their pupils. They are constantly looking to ensure their campus provides the best facilities, for both present and future pupils. The project was split into three phases:

  • Nursery – Phase 1: Relocate and expand the Nursery to provide extended all day, all year round provision.
  • Juniors’ – Phase 2: To replace the existing Year 3 and 4 classrooms with a new wing connecting Juniors and Science.
  • Infants – Phase 3: Replace the current Infants buildings with a new purpose-built Infant Block.

Enviromesh first became involved in the Abbot’s Hill School project as a result of NVB Architects in Somerset approaching us. We were initially briefed to provide design assistance for phase two of the scheme. This included plans for a Mass Gravity Freestanding Trapezoidal Gabion Retaining wall within the Juniors’ school garden. As a result of involvement during the project’s early planning stages. Enviromesh were able to positively influence key engineering and design decisions by providing practical solutions and technical advice. This included providing guidance from a construction standpoint. On how best to integrate the design proposals within the overall scheme in order to meet the wider project objectives.

As a result of advising on the design and technical engineering aspects in the early stages of the project. Borras Construction, the main contractor, approach us to supply and install the gabion wall solution based on the approved designs.


A central part of the design would require the installation of a number of freestanding, partially retaining and varying height trapezoidal gabion wall sections. Each section interconnected and orientated at 90° to the next. To achieve this, Enviromesh would need to fabricate a series of trapezoidal panels and interface panels. To create the corners between the uniformly inclined faces of each of the wall sections.


Scottish Beach Cobbles (being round and smooth) can be challenging to work with, tending to shift if not managed correctly. Mainly because adjacent surfaces do not interlock in the same way as irregularly-shaped 6G gabion stone. As a result they are classed as a ‘moving fill’.


Supply of Pillared Welsh Slate, delivered in cubic metres, non-uniform in size and machine-cut on site prior to installation. Once cut, the slate’s more linear nature will tend to pack in more tightly. The initial preparation of the stone would require the use of specialist equipment. Therefore would mean a slight delay in the construction schedule. As a material fill Welsh Slate is more expensive compared to standard rock fill materials.


The cost of using Scottish Beach Cobbles to fill the baskets would be prohibitive for this project. As a result, the trapezoidal baskets filled with these materials required re-specifying to include facing panels. These panels would create a separate, restricted space ‘compartment’ within the front face of the gabion basket. This reduces the overall volume of the more expensive fill material per basket. By restricting the pillared Welsh Slate and the Scottish Beach Cobbles to the exposed faces only. The 6G Granite gabion stone ‘hidden’ behind the facing stone therefore occupies the majority of the basket.

Featured Products, Applications & Services