Building-simulation is a valuable aid to plant sizing and assessing the performance of systems such as displacement ventilation.
With the performance of the entire building being what the new Building Regulations seeks to maximise, building-simulation software comes into its own. DAVID McCEWAN explains how such software is the key to integrated design.As everyone in the industry should be aware the English and Welsh Building Regulations are changing in April 2006 in response to the European Energy Performance of Buildings Directive. The implementation of the directive into English and Welsh law will play a vital role in helping the Government achieve its objectives for reducing carbon-dioxide emissions and radically change current methods for complying with the UK Building Regulations. A building’s performance will now be considered holistically rather than elementally, which has far-reaching effects on how buildings and their systems are designed. So what’s going on?
SAP 2005 will replace SAP 2001 for domestic properties below 450 m2, and the Target U-value and Elemental Methods will now be redundant. For non-domestic buildings and domestic properties above 450 m2 compliance will be achieved by analysis with the new National Calculation Methodology software tool SBEM or other accredited simulation software, such as IES’s Virtual Environment. The elemental, whole-building and carbon-emission calculations methods will no longer be valid. With performance being measured holistically, if the compliance of buildings is not considered right from the very start it is conceivable that major re-design will be required later on. Even seemingly minor changes can now have significant knock-on effects to the whole and, therefore, compliance. Either architects will have to start using compliance software tools while buildings are being ‘evolved’ or engineers will have to be involved at earlier stages of the design process. In my view, these changes to the Building Regulations will help promote a more integrated and holistic approach to building design with the emphasis on more effective and intelligent design at earlier stages. Building-simulation software, such as that encouraged by the new regulations, offers the tools necessary to enable such a shift in the design process. The detailed information provided by such software on the consequences of design changes allows those involved in the design process to make more informed choices, promoting design excellence and productivity. Opportunity knocks
The UK leads the world in having the highest proportion of buildings designed using building-simulation products at some stage of the design process, and most of this experience sits with engineers. Therefore, arguably this is a unique opportunity for many engineers who already offer consultancy services to architects. By offering the expertise by which to understand where potential problems in compliance might lie, M&E engineers can help architects in the decision making process. This will require their involvement earlier in the design process, which may make many architects uncomfortable. Whether architects take steps to understand these issues themselves or seek the advice of engineers, this encouragement for more effective communication across the whole design team is potentially one of the most important outcomes of the 2006 Building Regulations amendments. The use of building-simulation software provides the tools for this more integrated approach to design. Many, mostly larger, engineering firms have already invested in such software. As long as it complies with the selected tests, this investment will stand them in good stead. However, many smaller firms need to act quickly to ensure they do not lose out. It is not as difficult as many may imagine to integrate the requirements for the April 2006 Building Regulations into working practices. By using suitable software tools to consider performance criteria earlier in the design process, engineering consultancies will be able to easily understand where potential problems in compliance might be and how to overcome them. It is however essential that firms are careful to select the software best suited to their company’s needs by ensuring it fits easily into working practices and causes no additional work. IES has worked closely with large firms such as Arup, Connell Mott MacDonald, White Young Green, Gifford & Partners and TBA to integrate building-simulation software completely into the company’s culture — a process that requires close collaboration and support on training over a period of time. However, IES also works with smaller companies to supply software solutions suitable to their requirements. Ultimately, embracing the 2006 Building Regulation changes and the principles behind building-performance software makes perfect commercial sense, as well as addressing key environmental concerns.
Summary of compliance criteria for Part L2 of the forthcoming Building Regulations
1. Calculated carbon-dioxide emissions are less than a target based on a notional building. This target will be 23.5 to 28% lower than an equivalent or notional building designed to 2002 regulations. 2. Fabric and services perform to minimum standards. 3. Passive measures are provided to prevent excessive solar gains in summer where there is no cooling. 4. ‘As built’ must be consistent with the predicted carbon-dioxide emissions 5. Information is provided to the building operators.
David McEwan is divisional manager (building regulations) with IES Ltd, Helix Building, Kelvin Campus, West of Scotland Science Park, Glasgow G20 0SP.