BUILDING INFORMATION MODELLING
The construction industry of today is undergoing a rapid change. UK is one of the frontrunners in BIM technology in Europe, a mandate making collaborative 3D BIM (with all project and asset information, documentation and data being electronic) a requirement on its projects by 2016. This is given rise to a scurry by different industry players in the UK. Essentially the UK Government has embarked with industry on a four year programme for sector modernisation with the key objective of: reducing capital cost and the carbon burden from the construction and operation of the built environment by 20%. Central to these ambitions is the adoption of information rich Building Information Modelling (BIM) technologies, process and collaborative behaviours that will unlock new more efficient ways of working at all stages of the project life-cycle.
A bulk majority of the Irish building stocks are in dire need to retrofitting, with only 1 in 8 dwellings having a Building Energy Rating (BER) of F or G and only 0.1 % having a rating A (best), as determined by the Dwelling Energy Assessment Procedure (DEAP). Given the immense gap in the retrofitting needs of the Irish housing stock and the absence of a proper methodology to achieve that, there is a requirement for a tool that will be able to integrate the various aspects of building system.
The retrofit stakeholder value chain is complex and fragmented. Decision makers lack the knowledge, tools, and confidence to act in order to overcome the barriers to building renovation to low-energy standards. Therefore, the aim of this project will also address this problem by developing a standards-driven, systematic approach to building retrofitting, with a holistic package of solutions for Ireland.
The NZEB-Retrofit project will utilise the information rich Building Information Modelling (BIM) technologies. The researchers of this project are in the process of developing a ‘Building Energy Optimisation (BEO)’ tool that builds on an existing framework called the ‘Scenario Modelling method’. The scenario-modelling method recognises conventional performance analysis contexts and categorises them as building objects. These building objects can be micro (zone) or macro (building site, building portfolio or simply building). This method, underpinned by BIM standards, will work as a performance framework tool that would leverage the building energy performance. Once developed, this framework will be tested on demonstrator sites and field studies that consists of both dwellings and non-dwellings. A blow out of the BEO framework is provided in the figure below, showing the lighting aspect of the methodology.
Building Energy Optimisation (BEO) framework – Lighting performance aspect
There is a dearth of tools that support cost and energy effective retrofitting in Ireland. The industry, at present, lacks a systematic methodology that would help the stakeholders of a project to reduce wastages of time and resource in renovations. The BEO framework will provide retrofitting strategies (renovation scheduling, health and safety) and alternatives (efficient building materials, components and systems) and cost effectiveness guidelines (retrofitting costs and payback, life cycle costing), as seen in figure 2. It draws its input data from measured sources, standards driven numerical models that feeds into the simulation model as input parameters.
Moreover, an ‘Energy optimisation tool for retrofitting attending to indoor comfort requirements’, will be developed backboned by this framework. This will consider a wide number of comfort parameters as constraints (lighting, visualisation, acoustics and thermal comfort) and maximising energy efficiency and minimising GHG emissions based on these constraints. The approach is a novel one, since such a holistic approach to building retrofitting is lacking in Ireland. This tool will be focussed for renovation of Irish building stocks, with possibilities of further extending this methodology to other climatic zones and building types. Figure below shows the interrelationships between the performance aspects of this framework. This tool works closely with occupant behaviour, since our project draws from methods and expertise of social science.
BEO framework aspect interaction