Design
Land Planning Contracting Construction Refurb End of life
The design stage is the point at which sustainability objectives become embedded within the specifications for a development project. This is one of the most important phases in determining a successful outcome.
Traditional buildings consume large amounts of energy and other natural resources and can harm the environment around them. There is a great need for more eco-sensitive structures.
By considering the sustainability issues around natural resource use, human health, and community concerns at the design stage, designers can create buildings that are cleaner, healthier for occupants and the environment, and deplete fewer resources – both during construction and throughout their life.
Additionally, sustainable design options incorporate an important financial element as materials within buildings each carry their own costs and returns on investment.
- Monetary returns (pay back periods and lower revenue spend)
- Sustainable performance (e.g. carbon emission reductions)
A longstanding tension exists between maximisation of revenue for the minimum capital expenditure. Most investors/developers prefer to focus their spending to meet only their immediate objectives (for the public sector immediate objectives may be considered those within dominant political party timelines). However, sustainability alters this perspective; appropriate design that incorporates whole life costing can achieve greater monetary returns. This can be done through designs that ‘spend to save’, which involve higher capital expenditure to reduce running costs, or may be achieved through sourcing recycled products that require lower capital expenditure.
It is vital at the design stage that consideration is given to commercial factors during both construction and operation phases. Operating costs invariably outweigh construction costs and will therefore heavily influence design schematics of materials and systems. Designing in balance between capital and operational expenditure can have effects further downstream on product selection to meet the required specification, replacement lifecycles and planned maintenance regimes. Therefore, design must pay attention to the tensions between capital expenditure and revenue throughout the building lifecycle.
The Duchy of Cornwall case study, ‘Implementing a Sustainable Energy System at Poundbury’ illustrates how the estate has integrated sustainable building design with sustainable energy infrastructure whilst taking into account commercial factors such as energy costs and investment returns. The Duchy of Cornwall sought to facilitate this link through new ways of partnership working and set up an Energy Service Company (ESCO) – which brings together partners willing to invest in sustainable energy infrastructure with a view to making a return on this investment.
Key considerations
- What sustainability opportunities can be incorporated at the design stage?
- What variables should I consider at the design stage?
- What common methodologies and building assessment schemes can I use to design sustainability into buildings and their construction?
1. What sustainability opportunities can be incorporated at the design stage?
The design stage presents a key opportunity to:
- reduce energy consumption, both embodied energy in construction materials, such as aggregates, and operational energy expended from daily use, such as use of natural ventilation. Typical carbon embedded during the life cycle of building has been estimated at 5-10% for materials, 5-10% for construction, and 80-90% for operation and maintenance);
- reduce waste during design and use;
- provide high quality interior environments that are attractive to occupy and enhance productivity/user utility;
- provide healthier and safer buildings;
- showcase the local authority/owner commitment to sustainability;
- future proof buildings against climate change;
- make buildings more flexible for possible different future uses; and
- facilitate deconstruction and/or component reuse at end of building life.
Designers should consult with the owners and building occupiers to prioritise sustainability criteria to understand, for example, design codes or the objectives within a community’s Local Agenda 21. Approximately 25% of local authorities are applying the Merton rule, which requires 10% of renewable energy to be generated on site. Moreover, there has been some recent engagement with occupiers around green lease agreements. These are leases which include incentives for reduced resource use by both landlord and tenant. Green leases include detail of operational design for water and energy efficiency measures, lighting (e.g. metering, designing to maximise natural sunlight) and renewable equipment, tenant amenities (e.g. bicycle racks) and other shell and core sustainable design features. Green leases are still being explored between landowners and occupiers; however, occupiers have other means to influence sustainable designs. More information can be found from a presentation on green leasing by Michael Brooks, Executive Director of the Real Property Association Canada, given at the RealLeasing Conference, 2007.
The PricewaterhouseCoopers case study, ‘Embedding Sustainability in Development and Design Decision-making’ illustrates how, as the major occupier, PricewaterhouseCoopers has engaged in collaboration with environmental consultants, architects, and the site developer to influence the sustainable specification of a major new office build in London.
In addition, where applicable, engagement and education of those selling or leasing buildings, such as office Agents, is also important to ensure that all parties understand the value created by sustainable design.
Additional Design FAQs are provided further down this page.
2. What variables should I consider at the design stage?
A range of sustainability factors can be considered at the design stage, including the following.
- Treatment of vegetation corridors, protection of natural habitats and biodiversity to minimise disturbance at the construction site.
- Reuse of any existing buildings, their components or waste materials from construction such as recycling secondary aggregates for build of green roofs.
- Design encouragement for alternative modes of transport, such as cycle facilities and visual stimuli and lighting at street level to encourage walking.
- Recycling and composting facility space designed into the building.
- Grey water irrigation and low water consumption toilets.
- Alternative cooling technologies such as chilled beams, or traditional cooling designs such as opening windows.
- Reduced energy consumption through provision of natural daylight in offices, individual environment control systems, and where appropriate design of stack effects to circulate air through central atriums.
- Small adjustments to specifications for subjective factors such as internal comfort levels, which can lead to large energy reductions.
There has been some debate about the extent of chemical treatment use in sustainable buildings. Whilst many of these materials may be environmentally damaging to produce, their use can make a contribution to whole life value. Chemical treatments can reduce the need for replacement/refurbishment as chemical treatment can prolong component life.
Common methodologies for assessing sustainable building design include:
- The Building Research Establishment Environmental Assessment Method (BREEAM);
- Leadership in Energy and Environmental Design (LEED); and
- Community and Local Government (CLG) Code for Sustainable Homes.
A Code for Non-Domestic Dwellings is currently being explored by the UK Green Building Council.
The Arup Integrated Resource Modelling system case study illustrates a Life Cycle Assessment (LCA) approach to design.
Are there key considerations we haven’t included? If so, please let us know.
The following are a set of questions you should be asking yourself at this stage of the construction process.
- What sustainability standards should design aspire to? Will BREEAM or an alternative standard be used?
How far should design go beyond the regulatory minimum?
What will be the lifecycle costs and benefits of achieving different performance standards?
What will investors be prepared to accept in terms of capital cost, revenue, and payback, and how does that influence the sustainability standards design should strive to achieve? - What scope of sustainability issues should be addressed?
What is understood by 'Sustainability' and what element of sustainable design is most important to stakeholders?
What metrics are most fit for purpose to measure sustainability returns through designing sustainable technologies into buildings? What methodologies are most suitable for the project, energy use, capex, opex, carbon rating, emissions….? - How can direct benefits for building users be maximised?
What are owners/occupiers requirements or preferences? e.g. employees and productivity, customers and image.
What are the future needs of the users likely to be?
What are the operational savings to be made by designing in sustainability? - How can the design be ‘future proofed’?
Will use of the building be affected by climate change or by trends such as demography, IT and globalisation? How can this be designed for?
How can the building be designed to allow flexibility for future needs? - How can maximum community benefit be design for?
What are the needs of the local community?
Can the building be put to multiple uses to meet community needs?
How can the building be designed so as to fit with the local character or heritage?
Can masterplanning be used to integrate the development with its surroundings? - How can design minimise energy needs?
What are the relevant site characteristics e.g. sunlight, air flows, shading, and how can maximum advantage be taken of these?
What management control systems can be designed to prevent waste of energy?
Will partnering with local organisations develop a cost effective community or district energy solution e.g. an ESCO to finance sustainable energy technologies or infrastructures? - How can design minimise water use on site?
- How / what sustainable materials can be designed into the development?
What are the life cycles of materials in the supply chain (including 2nd and 3rd tier?)
Will more sustainable options meet other quality criteria and will sustainable options be available in the quantity required?
How can design support reclaiming materials at end of life e.g. positioning materials to provide access to them without unnecessary demolition? - How can design minimise construction waste?
Can the design integrate any of the waste from site clearance?
Do design components fit with supply options in terms of sizing and quantities?