What are the best net zero strategies for retrofitting existing buildings?

Start with a comprehensive energy audit to identify energy flows and inefficiencies. Prioritize effective energy efficiency measures, followed by strategic integration of renewable energy sources like solar panels. Implement smart building technologies for real-time monitoring and control, gradually transitioning to electric systems as required. Include energy storage solutions and demand response strategies. Engage occupants in sustainable practices and establish continuous monitoring for optimization.

When working with organizations on their project’s net zero certification journey, we know that the best place to start is with doing a complete and thorough understanding of the baseline performance of all assets or buildings in an organization’s portfolio. What you don’t measure, you can’t track; leading with quality data is key. In fact, the first step in our net zero certification process is to perform a carbon emissions assessment for a building or portfolio – or a detailed inventory of a building’s Scope 1, 2, and 3 emissions. Only after this is complete can an organization move forward with creating a truly informed net zero plan.

If this is done with any other process than a detailed energy performance model then we are on the wrong track. Consider this as an ASHRAE L3 type audit. Technology needs to be used, buildings simulated, and data analysed to get the correct answer to the question "how much energy should my building use in its current state". From there we can review and explore ways to reduce.

In my experience baseline data is critical to the successful retrofitting of existing buildings. I have participated in many energy audits and they are a good way to find the areas that are high energy consumers. Sometimes we find that equipment is not functioning as designed because of a failure of a tenant or owner to make repairs, replacements, and/or maintain. One example are faulty motorized dampers. Dampers can remain open allowing outside air to enter the space even when not needed. The air conditioning or heating system will continue to run in order to maintain a comfortable temperature. It is also important to talk to building staff as they are key to understanding why some changes to system were made.

Refer to Land, Sea & Islands Centre, Arisaig. This involved pre-refurb and post-refurb measurement of: - energy use - temperature - RH - u-values - airtightness - thermography

Good building envelopes / enclosure are enablers of low carbon heating and cooling systems. I’ve worked on several retrofit and decarbonization projects where the initial concept was ‘straight-up electrification’ - no demand management at the enclosure despite largely uninsulated walls, poor performing windows, and high rates of infiltration. Electrification without enclosure-focused demand reduction can require significant electrical supply upgrades prior to electrification, increase sizes for new equipment, contribute to poor thermal resilience, and result in a building being locked-out of a true net zero path.

I think this analysis is missing a step - the identification of low and no-cost opportunities to improve energy and GHG performance - these may include better controls of the “on/off”, enhancing start up and shut down, enhancing facility management, and improving tenant engagement. All of this should be done after establishing a baseline and before you tackle investment grade envelope action The great thing about no cost improvements in energy efficiency is the payback is immediate and the ROI is infinite :)

Prior to making capital investments, its important to utilise the assessment to establish a prioritised "Carbon Neutral" road map that considers capital costs, complexity of solution, ROI, and carbon impact to guide the investment criteria. Each building is different, and following a uniform playbook will yield uneven results at best, or undermine the carbon neutrality program at worst.

Building envelopes are a key element to acheive (mass) electrification and decarbonization. It is often overlooked as a traditional, not shiny component. However, minimizing energy demand (all the time) is critical to allow more buildings to electrify and not risk the electric grid. Peak demand management can be much acheivable once the overall demand is lower.

1) Contact your electric and gas provider to see what energy efficiency subsidies they offer. Take advantage of the money to help with the items above. 2) Look into information about indoor window inserts. The company Indow Windows has a game changing product reducing heat loss and conduction. 10% to 20% reduction of electric and gas! Also great option when replacing windows is not allowed or too costly. 3) Investigate micro-bubbles. Amazing technology that keeps water pipes clean of bio-film and hard water buildup. It can increase the efficiency of heat pumps by 15%. So much amazing new technology coming out!

The evaluation and understanding of energy conservation measures in large building portfolios are essential processes that span through to project lifetime. It starts with initial conceptual energy modelling, where simulations are created to predict the impact of various conservation measures. After this phase, the proposed conservation measures are implemented. Monitoring and reporting throughout the lifetime of these projects are vital, especially in the post-occupancy phase, to gather real-world data on energy use. This data collection is key to identifying efficiency gaps or determining where resources should be allocated or prioritized to enhance building performance.

One thing that is helpful regarding existing building retrofit which is also cost-effective is applying passive design such as natural ventilation, and shading. Moreover, applying climate resilience measures in energetic retrofits such as light-touch assessment for energy retrofits, indoor temperature monitoring using smart technology in high-risk retrofits, and provision of user manuals to manage heat in summer could be adoptable and efficient.

Circular economy: re-use of materials being stripped out. Health: use of materials, components and finishes that don't present a hazard to health.