Architect and Builder July/August 2015 | Page 113

Simple clay brick construction, the benchmark for all that is good about housing and social infrastructure buildings in South Africa, goes beyond the important fundamentals of durable, low maintenance structures with enduring aesthetic integrity to afford comfortable thermally efficient accommodation in which South Africans live, work and play. FEATURE ARTICLE SPONSORED BY COROBRIK to heat the SBH”. Certification requires that insulated ceilings must always be installed. It is ceiling insulation therefore, and not the supposed ‘higher thermal rating’ of the Panel Systems, that lowers the ‘heating’ energy usage to below that of an uninsulated solid clay brick walled house. With the highest certificated IBT in Africa shown up as failing to compare with basic solid double brick wall construction, it poses the question as to just how comparable the walling systems of the 31 other supposedly better performing IBT walling systems might be for meeting the challenges of providing sustainable social infrastructure buildings any way comparable to that which clay brick construction has done over the decades. Thermal Comfort in Context The Agrément SA certificates only reference ‘heating’ energy and in South Africa heating energy is only part of the energy consumed in buildings. There is a plethora of research, (Chapter: “The true thermal performance and energy efficiency of different walling envelopes” - The Sustainable Energy Recourse Handbook Volume 6) some of which will be referenced in this article that highlights the comparative inefficiencies of insulated lightweight walled buildings in attenuating indoor temperatures to thermal comfort levels on summer days. The ‘unsupported’ superior thermal performance claims of the proponents of lightweight IBT for school buildings aside, the fact of the matter is that 220mm solid double brick walls provide longest periods of thermal comfort during day-time. Learners and teachers who have experienced both types of learning environments will confirm that. The extent of this thermal comfort clay brick construction provides, relative to lightweight IBTs such as SANS 517 compliant LSFB, is well shown in the findings of thermal modelling research undertaken by the University of Pretoria, Clay Brick “A thermal performance comparison between six wall construction methods frequently used in South Africa”. This research included the modelling of three building typologies, the one being of a 2,000m² office/institutional type building as tabled below (Table 1). Clay Brick Outperforms Lightweight As shown solid 220mm double brick walling outperforms SANS 517 LSFB by between 10% and 57% de V