Flintmill and Underwood


Flintmill and Underwood

10 New Build, Zero Net Carbon, affordable homes for the Royal Borough of Greenwich utilising modern Methods of Construction (MMC).

The project was split between two adjacent sites; The Underwood site, which delivers 8 no. 2 storey houses which consist of 7 no. 2 bed (4p) houses, and 1 no. 3 bed (5p) wheelchair accessible house; and the nearby Flintmill site, which delivers 2 no. 3-bed, 2 storey wheelchair accessible semi-detached houses. Both sites are located on under utilised former brownfield garage sites.

Modern Methods of Construction (MMC) were utilised on the project to help achieve the councils aspirations for the project. Due to site access constraints, the site was not appropriate for volumetric modular construction, however it did lend itself to panellised construction, so SIPs (Structural Insulated Panels) were adopted. SIPs have many benefits including a low carbon footprint, rapid build times, high thermal performance and air tightness.  The loadbearing wall panels are extremely strong and lightweight and consist of inner and outer 15mm thick OSB 3 boards with PIR insulation injected in-between during manufacture.

SD Structures worked closely with the SIPs panel frame supplier to coordinate the buildings foundations and ground floor structure. We utilised a highly sustainable and efficient flooring system system at ground floor which replaces the concrete blocks in a tradition beam and block floor with Tetris insulation blocks. This reduced the buildings embodied carbon, has higher thermal performance and improves health and safety issues associated from lifting heavy concrete blocks.

The ground conditions were poor and the underlying soils had a very low ground bearing capacities however by utilising a lightweight frame and ground floor structure, we were able to justify conventional shallow foundations which resulted in significant cost and programme savings over piled foundations.

SD Structures provided construction design services for the substructure, below ground drainage and the civils and highways works. The project was delivered in 3D to BIM level 2 allowing the substructure and below ground drainage to be fully coordinated to prevent clash issues onsite.

We’re delighted the project was shortlisted for two categories at Constructing Excellence SECBE Awards 2021 for Building Project of the Year and Sustainability Building Project of the Year