Deep energy retrofit

Deep energy retrofits and conventional energy retrofits both undertake different approaches and lead to varied outcomes. In scenarios where capital improvements are being looked forward to in an existing project deep energy retrofit is certainly an upper hand decision to create the most value out of investments in the long term. Deep energy retrofits can be well-timed to reap maximum benefits in such situations.[2]

The overall success of the deep energy retrofit project also depends upon the inclusion of occupants in all the phases of the project. The phases include – project recruitment, project planning and during the use. Occupant behavior requires the project to focus on building owners’ needs and wants as much as the technical specifications. This ascertains actual performance, cost-effectiveness, willingness to progress from a design to an actual implementation, and occupant satisfaction.[4] Also, evidence suggests that our building simulation models can become more accurate for a given house when we include actual operational information, such as thermostat set-points, appliance usage, etc. (Ingle et al., 2012).[10]

Over-time retrofit is the implementation of a retrofit project which is planned in a step-by-step manner at intervals of time within a stipulated duration. Such an approach is usually sought for deep energy retrofits over an all-at-once approach to reduce the burden of large upfront costs and break it down into chunk of timely investments. Thus, over-time retrofit could at least be a viable option for a deep energy retrofit than going for conventional retrofits due to capital constraints. Research in the United Kingdom has demonstrated that retrofits carried out over-time can achieve levels of home performance equal to those achieved by all-at-once DERs (Fawcett, 2013; Fawcett, Killip, & Janda, 2014)[4][11][12] and select projects have been successful in the U.S. (Less & Walker, 2014).[13] Though such an approach has its own pros and cons which are compared as follows (Less & Walker, 2015):[4]

It is important to note that, for example, an overtime retrofit project could be able to stipulate the occupants' need over the time but could perform sub-optimal technically. It could also prove to be costlier. There's a lack of tools to execute over-time projects efficiently.[4]

Detailed planning must be inculcated from the very beginning. It is recommended to include post-occupancy evaluation at each stage of implementation to deal with modifications required in future stages. Home performance should be tracked at each stage either using utility bills or feedback devices. This helps in achieving the set-target for energy consumption. It must be kept in mind to implement building envelope and passive design elements before making major HVAC and technology investments. This will help to reduce the load parameters for HVAC design. The technology investments should also come later to have an innovation advantage. Over-time retrofits, thus can be guided by these strategies to overcome the challenges and achieve success.[4]

Deep energy retrofit project has different phases governing them – pre-panning, project planning, construction, test out. The beacon for the design and construction process in deep energy retrofit projects is a set of defined project needs, opportunities, goals and objectives. This completely determines the overall project. Walker et al. provide design and construction process guidance which can be followed flexibly in deep energy retrofit projects in residential homes.[4]

• Insulation improvements, usually to the foundation walls/slabs, above grade walls, floors, roof, and attic surfaces that make up the thermal envelope
• Attention to air sealing, particularly in areas that are harder to address without being paired with improvements to the insulation shell

• Upgrade to non-atmospheric vented combustion units that either vent directly outside or are electric only
• Upgrade to units that are correctly sized for the heating and cooling load demands of an altered building
• Improvement to or replacement of the existing distribution systems for heating, cooling, and/or hot water, including changes to ductwork, water piping, and wastewater heat recovery

The deep energy retrofit specifications for various elements vary from climate to climate zones.

"Buildings will also be particularly affected by the effects of climate change: storms, flooding and seepages, reduced durability of some building materials and increased risk of structure damage or collapse (e.g. from severe storms) could all decrease building lifetime, while increasing health-related risks such as deteriorating indoor climate." (The GABC Global Roadmap)[16]

From the industrial revolution, fast forward to a few centuries later. We have come far ahead with global warming and climate change. To counter the global temperature-rise problem, a decision was reached at the Paris agreement in 2015, wherein member nations pledged to maintain temperatures below 2℃, compared to pre-industrial levels.

The Global Status Report 2017 underscores the importance and potential of deep energy retrofitting among other solutions in achieving climate mitigation goals. Deep energy retrofitting is one of the solutions for cutting down the carbon footprint of buildings.

The report found out that buildings & the construction industry together accounted for 36% of global final energy use & 39% of energy-related CO2 emissions. It calls to action for a 30% improvement, by 2030, in energy-use intensity (i.e. energy use per square meter) of the building sector, as compared to the 2015 levels, to achieve the Paris agreement goals successfully.

Though a growing number of countries have laid down policies to buildings energy performance improvements but a rapidly growing buildings sector, especially in developing countries, has offset those improvements. The Report states that the efficiency improvements, including building envelope measures, represent nearly 2400 EJ in cumulative energy offsets to 2060 – more than all the final energy consumed by the global buildings sector over the last 20 years.[5]

It asserts that an aggressive scaling up of deep building energy renovations of the existing global stock is one of the important steps ahead. It points out to refer to Global Alliance for Buildings and Construction (GABC) Global Roadmap for building sector towards sustainability.[5]

The GABC Global Roadmap sets up to 'accelerate the improvement of existing buildings’ performance' towards energy-efficient, zero GHG emissions and resilient buildings well before the end of the century taking the following steps globally:

• Significant increase of renovation operations including energy efficiency.
• Upgrade of the level of energy efficiency of each operation, in line with long-term standards.[16]

An analysis for 50% dip in energy consumption & carbon emissions by the US by 2050 translates to comprehensive energy efficiency retrofits in more than half the existing buildings (Nadel 2016).[17]

The policy framework for retrofitting in USA is directed at state and local levels. These efforts are supported by the national government. Hundreds of such programs exist, right from the basic energy audits, provision of financial rebates, to comprehensive ones that aim to optimize the entire house.

Carine et al. summarize the below-listed elements present mostly in the best programs:[17]

• Retrofit consultancy for consumers.
• Marketing to boost the demand-supply in this industry.
• Training, certification of retrofit contractors.
• Provision of rebates, upfront discounts.
• Investment in R&D.
• Building-efficiency labelling.

The Home Performance with Energy Star program is run by many bodies in the US, with the aid of the US Department of Energy. This project reports an average cost of $3500 per home retrofitted, with a distribution of 57%, 14%, 29% to homeowner incentives, contractor incentives, & administrative costs respectively.[17]

In the commercial domain, the Energy Star Program by EPA aims to reduce the carbon footprint of buildings. According to this initiative, owners benchmark their buildings on a scale of 1-100. Those scoring 75 & above receive 'Energy Star' designation; while the others are encouraged to follow upgradation strategies for a better performance. Nearly 500,000 properties, representing about half of US commercial building floor area has been benchmarked as of 2016, with a grand total 29,500 buildings receiving the 'Energy Star' rating to that point.[17]

The retrofitting industry is steadily on the rise. Some major obstacles in its path include as found by Carine et al.:[17]

• High initial investment.
• Complexity of retrofits.
• Lack of awareness regarding retrofitting.
• Shortage of affordable financing.

The Empire State Building is undergoing a deep energy retrofit process that is projected to be completed in 2013. Upon completion, the project team, consisting of representatives from Johnson Controls, Rocky Mountain Institute, Clinton Climate Initiative, Jones Lang LaSalle, and NYSERDA will have achieved an annual energy use reduction of 38% and $4.4 million.[18]

A notable achievement of the project is that instead of replacing the chillers as originally planned, the design team were able to first reduce the building's required cooling capacity by 1600 tons, allowing for a chiller retrofit instead of replacement which would have been $17.3 million more in capital costs.

The City-County Building recently underwent a deep energy retrofit process that is projected to be completed in September 2011. Upon completion, the project team, consisting of representatives from the Indianapolis Marion County Building Authority, Indianapolis Office of Sustainability, Rocky Mountain Institute, and Performance Services will have achieved an annual energy reduction of 46% and $750,000 annual energy savings.

A business case study by The Rockfeller Foundation sizes the potential of retrofitting market in the USA. Retrofitting offers a burgeoning business market for entrepreneurs, engineers, investors in the USA. It offers a $279 billion investment opportunity. The residential sector, followed by commercial and institutional sectors, offers the largest business impact. Scaling up retrofitting efforts can create 3.3 billion direct and indirect cumulative job years in the United States.[19]

Cost effectiveness can be achieved when the annual energy cost savings can equal or exceed the annual loan costs. Their perfect balance is referred as neutral net-monthly costs. Cost effectiveness could be a key driver in decision making related to deep energy retrofit projects.[4]

A study by Less et al. (2015) found that:[4]

• The most cost-effective projects were the one in poor conditions- low efficiency equipment and little insulation. Such buildings did not pursue deep retrofit.
• The least cost effective projects were the ones having low pre-retrofit utility bills. But they had aggressive retrofit plans. Such a project cannot be said to be a failure because cost-effectiveness may not be the project goal.

Less et al. (2015) found that on average, the U.S. deep energy retrofits were cash-flow neutral on a monthly basis. However, variability was large, with some projects substantially reducing net-monthly costs and others substantially increasing net-costs. Questionable cost-effectiveness is thus, seen as a barrier to widespread of deep energy retrofits.[4] This forms the basis to think of economic value of deep energy retrofit in larger context.

Although many modeling tools are available to assess home energy savings, the inaccuracy of their predictions (compared to actual energy use measurements) limits their usefulness (Osser, Neuhauser, and Ueno 2012).[20] Cluett et al. point that the pilot programs should monitor actual energy savings to evaluate project impact and help calibrate estimation tools.[3] This is important to track, evaluate and verify reality-based energy performance metrics.