Sustainable refurbishment
[2] Sustainable refurbishment takes this a step further to modify the existing building to perform better in terms of its environmental impact and its occupants' environment.
Sustainable refurbishment is not a new concept but is gaining recognition and importance owing to current concerns about high energy use leading to climate change, overheating in buildings, the need for healthy internal environments, waste and environmental damage associated with materials production.
[11] Older buildings have significantly worse energy performance than their modern counterparts due to shortcomings in their design, deterioration in mechanical system efficiency, and increases in envelope permeability.
[13] Energy-efficient refurbishments are a tool to reduce energy consumption in buildings,[15] which will result in lower greenhouse gas emissions and resource use.
By providing resources, training access, and networking opportunities, they aim to close the gender gap in the industry while advancing sustainable refurbishment practices.
The indoor environmental quality of the existing building stock is known to often be more unsatisfactory and unhealthy than the outdoor environment due to the design and materials used.
[15][17] The "Citizen's Healthcare Principle" states that sustainable refurbishments must ensure that buildings are safe and improve living quality for those inside.
[15] The microclimate parameters that should be considered include: The preservation of historic buildings is inherently sustainable since it maximizes the lifespan of existing materials and infrastructure.
Non-sustainable buildings, in terms of their operation, also consume a significant amount of non-renewable energy resources, relative to other industries.
[2] This section lays out a timeline and progression of the development of the goals of sustainable refurbishment from a few different authors: The main goals of "sustainable development", by Baldwin in 1996, include minimizing the impact on human health and the environment, optimal use of non-renewable resources, utilizing renewable resources, and future planning and adaptability.
[15][18] Minimizing impact on the climate and ecological system is achieved through a reduction of emissions of greenhouse gasses, which is connected to the other goal of optimizing the use of non-renewable resources.
[15][19] The first part includes lower utility costs since less energy is consumed due to a combination of efficient and passive heating and cooling systems.
[16] A study in the United Kingdom showed that, after a refurbishment, buildings had lower operating costs even if sustainability was not a priority of the retrofit.
[15] This is quantified through life cycle analysis that measures the impact of a material over its lifetime, which stretches into the "D phase" that includes end-of-life waste after the building is demolished.
[15] When materials can be compared on the basis of a common bottom line, through life cycle analysis, an optimum path for the design appears.
Therefore, sustainable refurbishments should not include adhesives, paints, or glues that expel low-volatile organic compounds into the indoor air of the building.
[15] The model depicts how stakeholders expect the refurbishment design to yield energy savings, increased occupant comfort and health, extension of the building's lifetime, environmental protection, and, of course, an economic outcome.
The other context to consider is the ecological conditions, like the average temperature, humidity, soil quality, natural resources, topography, etc..[15] Green retrofits utilize an integrated design strategy.
This allows for minimal heat loss while mitigating concerns of carbon monoxide poisoning, radon gas, or harmful particulates accumulating in the home.
Most green retrofits will replace older single-pane windows with more efficient triple-paned varieties that are filled with an inert gas such as argon or krypton.
Intensive green roofs use a thicker growing substrate to accommodate larger plant species that require more space for their roots.
[14] The low energy demand even exceeded the new building standard requirements for 2021 by about 45%, making the design adaptable and resilient for the future.
The economic feasibility of a green retrofit depends on the state of installed systems of the existing building, the proposed design, the energy costs of the local utility grid, and the climatic conditions of the site.
[41] The EU has found that implementing green retrofit programs comes with the benefit of "energy security, job creation, fuel poverty alleviation, health and indoor comfort".
However, the technology to efficiently heat, cool, and power these structures do not yet exist, and they cannot completely rely on passive strategies due to more stringent code restrictions.
[2] Similarly, floor-to-floor heights impact the designer and contractor's ability to modify utility ducts, meaning that taller buildings are easier to refurbish.
[16] Research also shows that structures that qualify as "higher grade" building stock experience greater levels and frequency of sustainable refurbishment.
[2] It can be argued that it is not sustainable to replace building systems early in their lifecycle, just to invest in additional embodied carbon and discard the old equipment into a landfill.
It is not fair or just that only occupants that can afford premium housing get to live in the ensured healthy and comfortable environment of a sustainable refurbishment.
General Energy and HVAC Indoor Environmental Quality Material Choices Design Standards Several books on the subject have been published aimed at different audiences, for example:
