Cost optimal and nearly zero energy performance levels are principles initiated by the European Union’s (EU) Energy Performance of Buildings Directive, which was recast in 2010 and amended 2018. These will be major drivers in the construction sector in the next few years because all new buildings in the EU from 2021 onwards are expected to be nearly zero energy buildings (nZEB). While realised nZEBs have clearly shown that nearly-zero energy target could be achieved using existing technologies and practices, most experts agree that a broad scale shift towards nearly-zero energy buildings requires significant adjustments to prevailing building market structures. Cost-effective integration of efficient solution sets and renewable energy systems, in a form that fits with the development, manufacturing and construction industry processes, as well as with planning, design, and procurement procedures, are the major challenges.
The guideline presents a framework for ensuring the process quality of the new nZEBs. We will outline the key actions needed to ensure the achievement of energy and cost related goals presenting a replicable planning, design, construction, and operation process. The development of a clear and comprehensive life cycle process that includes the potential for specific and measurable actions (both cost savings and energy) is critical to ensure goals are met in a cost-effective manner.
In this guideline the “CRAVEzero process” is described. It organises the process of briefing, designing, constructing and operating nZEBs in different life cycle phases. Actions, stakeholder-relations, pitfalls and bottlenecks, as well as the required goals, are pointed out in detail. Considering the importance and the complexity to reach the nZEB standard in a cost-optimal way for all the different stakeholders during the process, multiple actions are required. These are however missing in the standard planning process. This report provides an operative methodology to achieve the best conditions towards cost optimal nZEBs in the whole planning, construction and operation process considering all relevant decisions, co-benefits, involved players as well as relevant cost reduction potentials. A process map that connects the entire project lifecycle for design, plan-ning, operation and end of life phase accompanies this report. This process map is a workflow that points out cost reduction potentials through all the stages of the process where all the different parts are linked to provide summaries and reports to the decision-makers in leadership roles.
The main additional advantages of integrating the “CRAVEzero process” into standardized building processes are listed as follows:
- Reduce risks
- Speed-up construction and delivery
- Control costs and energy performance
- Foster integrative design and make optimal use of team members’ expertise
- Establish measurable success criteria
Furthermore, during the whole process, four critical issues have to be tracked for new nZEBs:
- How efficiently can energy be consumed?
- How much energy can be produced on-site?
- Which environmental conditions can be controlled?
- How can be defined thermal comfort and what co-benefits can be expected?
As a main result this report also comes along with a downloadable “life cycle tracker tool”, an easy-to-use Excel file with VBA macros that combines project roles, actions, and design responsibility matrix. It is based on the experience of the whole consortium in the area of holistic project management with a focus on integral building planning of nZEBs. It gives support on how key performance parameters to achieve successful nZEBs should be prioritized and can be tracked along the whole life-cycle-process.