IRULES™ - Incremental Renovation to Ultra-Low Energy Standard

This is Zero-Carbon Solutions' new innovative planning system aimed at improving the profitability and environmental impact of existing buildings by introducing gradual energy-saving improvements in tandem with ongoing planned normal maintenance and renovation. By carrying out repairs, which would need to be carried out in any event due to building components reaching the end of their life cycle, according to an intelligent and comprehensive plan, the object undergoing maintenance/renovation will - after one maintenance cycle (20 - 50 years typically) - not only be a well maintained building in good condition but also feature very low space heating requirements, typically a reduction of up to 80% compared to the initial state.

This spectacular result is attained by consequently using passivehouse components, methods and calculations in combination with a planning principle, which realises each renovation step in such a manner that future renovation steps will fit into the system without requiring any work to be redone or changed. The end result is an ultra-low energy building, close to passivehouse standard.

For example, if the walls of a building are to be insulated by means of external insulation but the original windows still have some life in them, the components required to later fit proper triple-glazed passivehouse windows without having to erect external scaffolding again, are already fitted at the same time.

Or, if the roof needs to be renewed but the façades are not to be insulated at the same time, the roof overhangs are extended to accommodate a future external insulation at this stage of the maintenance process.

The IRULES™ process can be used on objects of all sizes and types but because of the planning effort, which is by necessity costly, it is best suited to large objects.

The IRULES™ process

The process is very flexible and adaptable to every situation. An outline of the steps in the process is presented below.

  1. Document the 'as is' condition of the object

    Doing this requires the following steps:

    • bring architectural drawings up to date to reflect the current state of the object
    • produce technical drawings of installations, etc.
    • produce technical specifications of all building components and technical installations, calculate U-values, etc.
    • produce an overall energy assessment of the object
    • calculate the object's current energy requirements using PHPP

  2. Establish a list of the steps included in a complete renovation/maintenance cycle if one doesn't already exist as part of the normal planned maintenance process, including at least these steps:

    • assess the life time remaining for each individual component in the maintenance list
    • based on that, produce a time line showing renewal/repair intervals for the components on the list
    • using the time line as a guide, establish potential synergies between individual, preferably (time-wise) overlapping, steps, e.g. use of scaffolding for more than one operation

  3. Analyse results and perform calculations. IRULES™ is mathematically a fairly complex process aimed at optimising and documenting both the profitability and environmental impact of the individual maintenance/renovation steps, e.g. by examining the synergies mentioned above. The system uses PHPP as the energy consumption calculation engine because this is the only calculation method really suited to and optimised to the use of passivehouse standard components. It is, however, not ideal for multi-zoned objects with a large number of zones and other simulation programs can be used.

    For profitability evaluations current-value calculations based on annuities and residual values are used, boiling down to an equivalent energy cost resulting from each individual measure and any combination of measures considered. This way the profitability of a measure under consideration is easily established: if the equivalent energy price is lower than the current or expected energy price averaged over the interest horizon used then the measure is profitable. So, advanced mathematical methods are used to facilitate the management decision processes. It is important to understand that investments in energy efficiency are always and entirely offset against savings in energy costs; hence, if financed by new loan capital there is no need to carry out an alternative investment analysis.

    This process is far from trivial given the often large number of variables. For example, it is sometimes profitable to move forward replacement of components despite these having residual life time, to avoid having to erect scaffolding twice. It is also necessary to clearly list, and fairly rigorously evaluate the sanity of, all assumptions made throughout the process.

  4. Make decisions based on the analysis (or take the decisions evident from the analysis). The analysis carried out using PHPP and the mathematical models iteratively will create a quite solid foundation for decision making, both economically, financially and technically. At this stage a full-cycle maintenance/renovation plan is designed.

  5. Detailed planning of all steps and any transitory measures necessary to integrate steps which are not coincident in time. This will include full technical integration leading to the goal of an ultra-low energy building as demonstrated by PHPP calculations. Detailed technical integration is of the utmost importance to the production of the desired result at all, and in the most economical manner certainly, e.g. planning and preparing for future installations that must penetrate the airtight layer of the building when carrying out external wall insulation; or preparing the detailed cold bridge free connection of the insulation and airtight layer of a new roof to be installed later than the wall insulation. This planning often involves the development of new solutions some of which need to be fed back into the mathematical models, leading to additional iterative steps and possibly changes.

  6. Write down a conclusive plan. This is primarily a technical plan, which is directly operative, including detailed drawings of special solutions, quality control methods, etc. A separate report may be designed which will outline economical assumptions, e.g. expected developments in energy prices, with associated milestones and alarm bells.

The Relevance of IRULES™

This type of scientifically based renovation/maintenance systems aiming to cost-effectively produce huge energy cost reductions in buildings according to principles, where each small step is in itself profitable and sometimes even largely self-financing is cutting edge thinking. It solves financial issues with huge complete low-energy renovation projects while gradually reducing energy consumption in step with each measurement and thus offers owners a financially and economically viable method towards sustainability in existing objects.

Whereas the mathematical models and methods have already been developed and smaller projects scientifically researched (mainly under the auspices of the Passivehouse Institute in Darmstad, Germany, where many of the philosophies underpinning IRULES™ were also developed), no large real-life project are yet under way using the IRULES™ method. Hence, we invite potential clients who find this of interest, to get in touch with Zero-Carbon Solutions. It is a method of great potential economic and environmental impact, both for individual users and for society as a whole.