By Malcolm Thomas – Chartered Building Surveyor
Arguably the challenge of sustainability is the greatest long term issue facing the human race and it has profound implications for managing buildings. Adopting a sustainable approach to design, construction, building occupation and maintenance attempts to address this challenge
In order to minimise environmental impact some of the key issues to be addressed at different stages during the property lifecycle include:
- Energy efficiency
- Drainage and flooding
- Safety and well being
- Pollution and waste
- Travel and transport
- Water use and recycling
- Land use and the use of materials
A fundamental shift in emphasis in building maintenance management is required and a deeper and broader knowledge of building performance is now necessary. Within an increasingly regulatory context of environmental protection, building owners and users increasingly seek improved sustainability performance from their buildings.
During the lifetime of a building a significant quantity of raw material and other natural resources are consumed, and tonnes of waste and emissions are produced. The concept of embodied energy has gained ground over recent years in this context. In order to reduce the environmental impact of buildings the energy used during the construction, as well as that consumed during occupation, has to be reduced.
Embodied energy is the total quantity of primary energy consumed during the lifetime of the building. Included in this calculation is the energy used in manufacture, transportation, construction, building use and ultimate demolition. Specifying the use of recycled materials, avoiding building systems with high maintenance requirements and adopting measures to reduce the incorporation of embodied energy are some of the ways that building professionals can assist in reducing consumption.
The increasing recognition of embodied energy in buildings, together with the continual rise in energy costs, is helping to drive innovation in the manufacture of building products. One example is the development of a new process for the manufacture of cement, which uses significantly less fossil fuel as a primary source of energy. A second example would be the increasing practice of procuring building materials through local suppliers for retrofit projects and thereby minimising transportation of components and reducing the carbon footprint.
Other new developments include:
- Algae powered facades
- Photo-bioreactors cultivating micro-algae to generate biomass and heat
- Ultra-light aerogel insulation
- Exploiting the tensile properties of bamboo fibres for structures and using cross laminated engineered timber in high rise construction.
Sustainability increasingly addresses a wide range of issues in attempting to reduce environmental impact, whether it be for new builds or refurbishment and retrofit projects.
- Environmental design strategies: passive design, maximising daylight, building orientation (facing rooms to benefit from lower solar heat gain), shelter and shade (roof overhangs to enable low solar heat gain in summer and higher useful winter solar heat gain), natural ventilation
- Energy and carbon dioxide emissions
- Building materials specification: reused materials and responsible sourcing
- Waste, recycling and pollution: site waste management
- Water conservation and harvesting
- Sustainable drainage systems
- Waste water recycling
- Surface water run-off and flood risk
- Ecology and biodiversity
- Spatial planning also contributes through reduced travel, suitable density of development, reduced car parking and providing links to public transport.
Sustainable design and construction is having an impact on the management of maintenance and building pathology in a number of ways. Whilst this impact is particularly evident in the area of energy efficiency, it is nonetheless felt in the implementation of sustainable measures generally, including rainwater capture, grey water recycling and waste and pollution reduction. This requires knowledge and understanding of how new and existing buildings perform when new materials, building techniques and technologies are incorporated.
Building surveyors perhaps more than ever need to involve facility managers in considering the maintenance implications of all materials, products and services proposed for development schemes in terms of:
- The potential to design out the need for maintenance through the judicious choice of materials e.g. self-cleaning, breathing and solar control glass; heat reflective paints incorporating nano technology; self-healing concrete utilising titanium dioxide on its surface to break down organic dirt
- Mandatory provision of easy access for maintenance e.g. rooftop man-safe cable and harness systems
- Need for specialist knowledge e.g. micro combined heat and power systems; air pressurisation testing
- Installation and servicing e.g. solar panels, inverters and heat pumps; integrated solar PV (Photovoltaics) for windows, roofs and facades; vertical axis wind turbines
- Maintenance e.g. green roof surface and drainage, sustainable drainage systems, air source heat pumps, solar panels, water harvesting and recycling plumbing and pumps; hygienic coatings incorporating non leaching antimicrobial agents
- Availability and cost of spare replacement parts e.g. LED light fittings; air and ground source heat pumps
- Further potential to develop building management systems to monitor electrical and mechanical plant and equipment e.g. smart meters linked to BMS (Building Management Systems)
- Management of risk e.g. sustainable urban drainage systems; innovative flood protection; mitigation measures for adapting buildings to cope with extreme weather.
The sustainability or “green” agenda now imposes higher design standards in refurbishment and retrofit. These standards include improved energy performance, reduced environmental impact and providing healthy, comfortable and safe environments, all of which offer higher occupant satisfaction and productivity. Technological improvements in building materials and in renewable energy generation can also make a positive contribution in heritage protection and conservation.
One key objective is improved energy efficiency. In this context energy efficiency is taken to include reduced energy consumption during the occupation and use of buildings, together with the generation of renewable power and heat from low and zero carbon sources. Viable alternative sources now being extracted include natural gas from methane hydrate and shale, and ocean thermal energy which generates power using warmer seawaters. Reduced energy consumption can be achieved by combined actions such as improved thermal performance of the building fabric; more efficient space heating and cooling, water heating and lighting; and by changing the behaviour of building users and occupiers. There are exciting challenges and times ahead.