Porotherm blocks, Contour Homes project

Project: Contour Homes project, St Mary’s Way

Porotherm, the clay block walling system from Wienerberger, has been specified to help achieve the highest levels of sustainability for a new Oldham housing scheme. The Contour Homes project at St Mary’s Way is a development of 93 family homes across 2.2 hectares with a neighbourhood park and green walkways.


Funded with a £7.84m Housing and Communities Agency grant, the overall development is being built to the current Level 3 standard of the Code for Sustainable Homes (CSH). Four specific properties, however, are being built to Level 6 as part of a trial.  Contractor Keepmoat Ltd selected Porotherm for the structural internal cavity walls for this part of the project.


The Porotherm construction system combines the use of a precision-engineered, multicellular clay block with a specialist ZeroPlus mortar to build strong, weathertight walls within a shortened timeframe. By using Porotherm, the scheme achieves extra credits under the materials section of the CSH. Additionally, each of the four Code 6 semi-detached homes will also use mechanical ventilation heat recovery system and roof mounted solar panels.

The completed walls, using 140mm Porotherm blocks, 150mm Xtratherm insulation and a 100mm external facing brick, achieves extremely low thermal conductivity of 0.12w/mk in a wall that is just 390mm thick. The clay blocks themselves have a better thermal mass than alternative structural construction options, such as timber or concrete blocks, for storing and releasing heat, helping to create a comfortable internal environment.

Louise Marsden from Contour Homes, part of the Symphony Housing Group, said:

“In this age of environmental awareness, a strong demand has emerged for more sustainable products and services which will limit the affect of climate change. With a need for more homes that have less environmental impact and lower running costs, house builders now have an excellent opportunity to explore and develop more sustainable construction methods.”


“At St Mary’s Way, we had an opportunity to trial some of the innovative products and systems on the market which offer low carbon, low energy and high thermal performance. In addition to the Porotherm system, we specified a range of building materials and technical solutions for the Code 6 homes which will combine to achieve this.”


Bounded by St. Mary’s Way, Egerton Street and Horsedge Street close to Oldham town centre, the 2.2 hectare gateway site is a key regeneration area for Oldham Council. The development is set to be complete by spring 2013.


Design architects Nicol Thomas, structural engineers Capita, project managers and planning supervisors, Arcus, together with cost consultants, The Simon Fenton Partnership, make up the consultant team. The building merchant supplier is EHSmith.