South Africa has enjoyed some of the lowest energy costs in the world. Energy-efficiency building has been seen as a luxury rather than a necessity. New legislation to improve the total building energy-efficiency footprint has been introduced in South Africa, taking a holistic look at building processes. Wispeco Aluminium has taken the environmental requirement to heart and has designed a highly sophisticated and user-friendly software package, U-Solve, aimed at assisting the South African market.

U-Solve is the only programme available in South Africa that will calculate actual certified whole-window U-values and SHGC values based on Wispeco’s range of aluminium extrusions. The latest version of U-Solve now also includes several new additions and features, to better assist the user in the design process.

U-Solve is endorsed by the South African Fenestration and Insulation Energy Rating Association (SAFIERA) and the results are verified by formal SAFIERA test certificates issued against actual “hot-box” testing.

The most recent version of the U-Solve software allows the user to design aluminium windows, doors and shop fronts by specifying both the configuration and the dimensions of the design. U-Solve then calculates the certified U-value and SHGC values of that design, and no approximations are used.

A wider range of glass types have been added to the latest version of U-Solve, all backed by official International Glass Database (IGDB) numbers. The programme includes glass codes for selected PFG and McCoys glass products, as well as a range of generic glass codes. The U-values and SHGC values calculated are not the Centre of Glass (COG) values, but rather the whole-window values, which take both the aluminium frame and edge of glass effects into consideration.

A further and exciting addition to the software includes a costing feature. This will assist the user by presenting an estimated cost for the design, as well as an estimated project value, which will be present on the summary report of the project.

U-Solve also performs the full SANS 204 calculation for the fenestration element of the building. The actual U-values and SHGC values, determined during the design process, are used to perform the SANS 204 analysis. The programme includes built-in solar exposure factors, which correspond to the specific climate zones of South Africa. The user can also specify individual shading ratios (P/H ratios) for each window, door or shop front.

U-Solve allows the user to easily change the frame and glass type to evaluate the effect on the overall thermal performance. In this way it becomes simple to determine the minimum requirements compliance with SANS 204. There are several reports available in U-Solve, which can be submitted in conjunction with plans to municipalities and local authorities for approval. U-Solve is available completely free of charge from the U-Solve website (

Tel: (011) 389 0053