Magowan Park, Derry

127 houses and apartments on a former high school site.

Ground models were created, after which full cut & fill exercises enabled civil engineers to design three level platforms from a steeply sloping site within an orbital access road. This was done with minimal removal of material off-site.

Retaining structures of up to 3.5m were designed to enable the creation of level back-to-back gardens.

A TAS retaining wall at the lower end of the site was raised to effect drainage.

Contamination hotspots were remediated, notably around the removal of a deep basement and fuel tank. Hydrocarbons were capped with an inert layer of clean, imported material.

Various drainage design options were considered due to the complex nature of the gradient, underground services and siting of roads and homes. An existing large-diameter, combined storm and foul sewer had to be diverted prior to construction. Close liaison with NIWater and Rivers Agency resulted in the speedy provision of a newly requisitioned storm and foul sewer.

Being built in excess of 1m above the surrounding land, Geotechnical approval was secured for road design and construction. A right-turning lane off Southway was formed to access the site and constructed under an Article 3(4c) agreement for modified public roads. Traffic-calming measures and safety fencing were added.

Dwellings were constructed from traditional masonry on strip-fill, piled and trench-fill foundations according to ground conditions. Roofs were on timber supports.

Click to expand the photos below