St Crispins School, Edinburgh

St Crispins School, Edinburgh

Client: The City of Edinburgh Council
Architect: Currie & Brown
Cost: £14.0m

We provided full Structural and Civil Engineering services on this project which comprises a new school for children with additional support needs located at the site of the former Burdiehouse Primary School which was demolished in 2010. The school is to replace the existing St. Crispins School located approx. 2 miles north of the proposed site.

The site lies within an existing floodplain nominally above the adjacent Burdiehouse Burn, with steep embankments along North and West boundaries. Extensive 3rd party hydraulic modelling was carried out of the burn to position the building out with existing 1:200 flood plain and ensure that building occupants are not at risk for 1:1000 event +30% climate change. The solution dictated the building geometry where if follows the floodplain with building levels raised predominantly out with it. The local land raising within the floodplain was offset by providing compensatory storage within the site boundary. Following objections from SEPA to land raising within a floodplain, planning was referred to Scottish Ministers upon which it was accepted.

A key parameter for the new school is to limit complexity of internal detailing, so as to not adversely impact the students senses. This allows for simplicity of construction method as the primary structure will generally be concealed. The predominantly single storey nature of the development lends itself to a lightweight construction in the form of a braced steel frame.

Due to the need to raise the building footprint levels out with the flood plain a concrete raft foundation solution was adopted supported on compacted engineered fill. This was found to be cost effective when compared to alternative ground remediation solution. In addition it concentrates the majority of works above the water table and limits differential settlement across soils of differing compressibility.