Decarbonizing buildings through retrofitting

It is commonly accepted that about 80 % of the buildings that will exist in 2050 have already been built. This, therefore, highlights the colossal role that energy-efficient retrofits will play in the journey toward net zero in 2050. However, progress in this domain has been slow, hindered by project economics that does not always make sense or landlord strategies based on holding the assets with minimal interventions

Retrofitting not only addresses the reduction of carbon emissions but also inherently embraces the principles of the circular economy. By repurposing and optimizing existing structures, retrofitting prolongs the life cycle of the embodied carbon within existing buildings

We spent 90% of our time inside the buildings and the average level of pollutants inside the buildings is estimated to be 2-5 times more than in an open environment.

Air quality inside a home is affected by both toxic chemicals inside the home and pollutants brought in from the outside. The activities of the occupants also create pollutants, such as smoke from tobacco and from the burning of wood, coal, and kerosene. Toxic fumes and chemicals are found in sealants, cleaning products, lead paint, asbestos insulation, damp carpets or fabrics, and certain pressed-wood furniture products that release chemicals into the air

So green building and particularly remoulding the existing building, will have more impact on our health and wellbeing, skyrocketing energy costs and impact on natural climate.

Green remodelling emphasises making homes as efficient as possible -using energy efficient appliances and thermostats, they can be programmed at different temperatures at different times of the day.

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Building and Site Assessment:

Understanding how the site and micro-climate affect the home?

How it interacts with its physical surroundings – specifically, sunlight, water, and wind?

What can challenge home performance and levels of comfort?

Trees and adjacent structures can be assessed for desired shading or solar access potential and natural ventilation.

The foundation of green remodeling is performance-based systems integration: understanding how the structure, finish, furnishings, and mechanical systems all work together to make a home safe, healthy, efficient, and durable.

The six elements to assess are:

·??????Building-site interfaces

·??????Home Performance

·??????Mechanical systems

·??????Interior structure and space

·??????Materials and

·??????Hazards

Cost-Benefit Analysis:

Cost-benefit analysis is an important part of the planning and design process with the client. Green remodeling has a special opportunity to show how systems integration can actually improve long-term cost-benefit outcomes.

The most cost-effective approach is to redefine the project from a major addition to a reconfiguration of existing space. During the building and interiors assessment, the better approach would be to deconstruct and rebuild that portion of the home.

Building Envelop:

Improving the building envelope is almost certainly on the project list if the owner is interested in improving the building’s energy efficiency. The extent of the work depends on the budget, schedule, and existing conditions. A whole-house energy audit will identify where the greatest impact can be made and adding to or replacing existing insulation is likely to be at the top of the list.

Building Systems:

·??????Plumbing

There are many ways to reduce water demand, including installing Water Sense-labelled plumbing fixtures and kitchen and bath faucets

On-demand hot water recirculation system and an under-sink water filtration system would also help. Look into the opportunity to use solar panels for domestic hot water

·??????HVAC, Lighting, and Electrical:

Depending on the age and condition of the existing building systems, much of the HVAC equipment may need to be replaced and upgraded

Make sure that all existing ductwork is cleaned if being reused. In the kitchen and bathrooms, install efficient and effective ventilation to remove moisture and odors from the home.

To bring daylighting into dark interior spaces, consider the use of solar light tubes. Interior lighting should be a mix of energy-efficient, color-correct ambient, and task lighting.

·??????Appliances:

Look for Energy Star labels on appliances wherever possible, including refrigerators, freezers, washers, dryers, and dishwashers. Also, consider the energy used by small appliances and electronics.

Electronic or IT equipment can use anywhere from a few watts up to 20 or more even when it’s turned off. Multiply that by the number of electronic products in the house, and it can really add up.

Building Interior:

·??????Walls, Ceilings, Floors, and Flooring Products

Indoor air quality can be seriously affected by the off-gassing of interior building products such as interior sheathing, adhesives, caulking, and sealants.

Look for products that do not contain VOC (Volatile Organic Compounds), such as interior paints and finishes. Lighter colors will reflect light better and appear brighter than darker colors.

Investigate the condition of existing flooring and subflooring and determine if reuse is a viable option. Wood floors may be refinished using environmentally preferable processes and products, and the existing floors may often be of a higher quality than the wood flooring products on the market today. Salvaged hardwood flooring is also a good choice when compared with wood laminate products.

Select hard-surface flooring rather than carpet to minimize allergens and maximize durability. Avoid carpeting in high-moisture areas such as bathrooms and kitchens

·??????Furniture and Built-In Millwork

Assist the owners in choosing products that are locally sourced and well-made. Consider purchasing reused, antique, or refinished furniture items.

Consider reusing clean existing cabinetry or buying salvaged or refinished cabinetry if available. Select materials that are easy to clean and maintain.

·??????Painting

It's important to recognize and avoid potential hazards that painting projects can create. These fall into two general categories:

·??????Hazards related to the painting process (namely lead-based paint risks)

·??????Hazards introduced by the paint products themselves

Remember that these hazards will first affect the painting crew, but the effects can linger after the homeowners move-ins.?

·??????Bathroom

Bathrooms and kitchens are the most common and often the costliest renovation projects. They can add considerably to the home’s value for resale. They also represent the greatest opportunity for environmental impact, with potential savings in water use, energy use, and improvements in indoor air quality

The bathroom is where most of the indoor water is used in a home, and energy is consumed by heating water, as well as lighting, warming, and ventilating the space.

The greatest opportunities for greening a bathroom remodel come from managing water, but in two very different ways: incoming use (supply pipes) and outgoing flows (both liquid and vapor). Green bathrooms need the highest-performing faucets, showerheads, and toilets. Walls must be designed and constructed to handle both liquid water and high humidity. Exhaust fans should efficiently and quietly move water vapor and odors out of the space.

Making the bathroom larger may be a “want” rather than a “need” of the clients. In the initial room assessment, look at the size of the existing space and determine if an expansion is possible within the home’s current footprint

A good bathroom design will find the right balance between utility, aesthetics, and resource efficiency

·??????Bedrooms

People spend more time in their bedrooms than in any other room in the home, so it makes sense that the materials installed and the resulting air quality in these spaces should be the cleanest and healthiest possible. Remember that we spend up to 90% of our time inside buildings, and about a third of that time is spent sleeping. Healthy air, confidence about freedom from potential hazards, such as electromagnetic fields, and relaxing aesthetics all contribute to the sense of well-being that should be found in bedrooms.

The remodeling and renovation of any interior space can be driven by many factors, but the home’s sleeping areas are the most private and personal of almost all the spaces. Clients almost always want larger bedrooms

Creating a healthier environment for those with allergies, asthma, or other sensitivities will almost certainly revolve around a better sleeping space. Replacing furniture and interior finishes, especially mattresses, may be enough to satisfy the client’s needs on a limited budget.

Air quality is especially important in sleeping areas. Evaluate the existing finishes and furniture and look from off-gassing from VOCs. The presence of flame retardants, heavy metals, plasticizers, or biocides in drapery or bedding can have an impact, especially on people with environmental sensitivities. Perhaps there is a need for improved indoor air flow especially at night. If the windows are in poor shape or are not operable, consider replacing them.

Climate

Any retro project must take into account the specific type of climate and site of the home and design for optimal climate response

The best way to analyze the options is to use an energy modeling tool, exploring how changes in the building envelope and HVAC performance optimize the remodeled home’s performance.

Deep Energy Retrofit

A deep energy retrofit is designed to radically improve the energy performance of the existing home. Total household energy reductions of 50% to 90% can be achieved by addressing all or nearly all loads, including space conditioning, hot water, lighting, appliances, and plug loads. Passive solar design and renewable energy systems are common in these projects.

Energy reductions of this magnitude require an intensive and extensive systems approach: the inherent relationships among energy, indoor air quality, durability, and thermal comfort must be understood and maintained throughout design and construction.

Rainwater Collection

We spend so much time getting water away from our homes that we often fail to see rain as a valuable asset–delivered right to us for free. It is in fact a great resource that can be managed to the advantage.

Rainwater collected from the roof can be stored for later use outdoors in the yard.

Cisterns store from several hundred to thousands of gallons of water, enough to significantly reduce or eliminate the use of municipal water for landscape purposes, especially when combined with the use of water-wise plants.

Rain gardens are a relatively new concept in garden design and are a great way to deal with stormwater runoff. These landscape elements feature plants that thrive in wet conditions coupled with soils that allow safe ground percolation. Rain gardens must be carefully designed and located to avoid flooding and causing damage to the home or neighboring properties.

Conclusion

Older buildings contribute to exceptionally high energy demands and high levels of greenhouse gases, most of which can be attributed to the burning of fossil fuels for space and water heating and the generation of electricity. Therefore, to reach zero emissions in the most cost-effective and practical way, it’s crucial that we also lower energy demand.

Correspondingly, we also need to address energy inefficiency. Accelerating efficiency retrofits will ensure that our future building stock is suitable for a zero-carbon economy.