Developers are showing a growing interest in sustainable development, but many are not convinced that the reward is worth the cost. Gardiner & Theobald crunches the numbers and gets some interesting results
The client was English Partnerships, design was by Edward Cullinan Architects
When developer Land Securities issued procurement guidelines that included an environmental policy, and asked all suppliers to demonstrate how they would seek to comply with it, it was yet more evidence of the industry’s growing commitment to sustainable development. Sustainability is now on the agenda of all construction industry clients and stakeholders. Government regeneration agency English Partnerships, for example, requires that all development on its land make the BREEAM’s “very good” standard.
Sustainable development involves a balanced approach to social progress, protecting and enhancing the environment, making prudent use of natural resources and maintaining high and stable levels of economic growth and employment. These principles are embedded in regeneration, which is about the re-use of resources – whether that means derelict and brownfield land, redundant buildings or local people whose skills are being underused.
Adding value
The building industry’s commitment to sustainable development can be encouraged if it is seen within a framework of adding value. Demonstrating that sustainable development is achievable as part of a developer’s core building strategy can provide many benefits: better quality buildings, lower eco-footprint, lower operational and running costs, enhanced attraction for building users and purchasers, reduced obsolescence, increased funding opportunities and maximised potential.
We are all linked to projects that try to be more sustainable and we each have our own definition of what that means. We know that legislation is changing industry attitudes to sustainability and that public awareness is increasing. This raises three key questions:
- How do we assess sustainable development in a consistent manner?
- How can we encourage an increase in current standards?
- How do we make sure the costs stack up?
Assessing performance
A range of systems is available for assessing environmental performance. BREEAM is the leading benchmark method. It aims to distinguish buildings of reduced environmental impact and encourage best practice in design, operation, management and maintenance. Conceived as a badge for marketing developments, it is now widely used as a specification, design and review tool. The use of a rating system such as BREEAM enables the environmental impacts of construction to be addressed in one target. It allows developers a degree of flexibility in the way they meet the sustainability target. For planning authorities and developers alike it gives an independent measure so all development standards can be judged on a level playing field.
Environmental benefits can be achieved through locally sourced materials to reduce embodied energy
Projects are assessed against criteria of: energy; transport; pollution; materials; water; land use and ecology; and health and well-being. Credits are awarded under each criterion, weighted and aggregated to give ratings of “excellent”, “very good”, “good” or “pass”, which can subsequently be used to promote the project.
BREEAM’s criteria will form the basis for the new code for sustainable buildings the government is launching in the autumn. The code will initially apply to all public housing constructed in the Thames Gateway housing growth area, but it is expected to be applied more broadly over time.
Design was by PRP Architects and contractor was Willmott Dixon
Increasing awareness
BREEAM is helping to increase public awareness of environmental performance. Allied to this widened appreciation is a potential increase in the marketability and value of sustainable development. This trend is set to continue.
There is consumer demand for sustainable homes. A survey carried out by WWF as part of its One Million Sustainable Homes campaign found that 87% of homebuyers wished to know the environmental rating of a home they are considering buying. And 84% said they were willing to pay an average 2% more on the purchase price for a sustainable home.
But does sustainable construction need to cost more and how can we minimise the costs? The 10 lessons that start on page 41 can help ensure the affordability of sustainable development.
Exceeding the standards
Increased standards of minimum environmental performance are now required for new buildings and major refurbishment projects. Exceeding these standards can make good business sense and need not involve significant additional cost. Prohibitive costs will not be incurred where good design is linked to a clearly defined and costed brief. However, economic viability will depend on recognising the full implications of sustainability targets at the start of the project and working creatively to achieve best value.
Ensuring affordability: 10 lessons for sustainable development
1 - Set early targets
Developers prioritising sustainability may target standards from BREEAM or other badging systems. Targeted standards can be met cost-effectively if they are understood early. Rating systems such as BRE’s Ecopoints can be combined with whole-life costing to identify which design decisions have the greatest long-term environmental impact. Planning authority requirements, especially in terms of renewable and/or decentralised energy supply systems, must also be understood at an early stage if these components are to be successfully integrated into the design and cost plan for the development (see “Planning guidance”, page 44).
2 - Establish commercial viability
This is crucial where sustainable elements may command a cost premium. Ways of improving value should be considered; for example, sunspaces or integral conservatories that fulfil an environmental function and increase the usable area.
3 - Exploit supplementary funding opportunities
It is likely that highly sustainable construction will add to the overall costs. A complex and diverse array of grants is available to help developers to fund these additional costs.
4 - Exploit taxation incentives
The landfill tax, aggregate levy, climate change levy, and enhanced capital allowances encourage good practice in responsible waste management, recycling and the use of energy-efficient technologies. The financial incentives offered by these initiatives can increase a project’s viability.
5 - Consult widely
The viability of a project may be proven on the grounds of stimulating growth and regeneration within the surrounding area. The sustainability credentials of a development can generate prestige and publicity. The business plan should recognise the potential for exploiting this, in terms of winning stakeholder support and funding. Where a development forms part of a wider regeneration initiative, there is even greater potential for enlightened thinking – for example, linking power generation strategies between sites.
6 - Think laterally
Innovative sustainability features may be deemed uneconomic if appraised using traditional estimating techniques. Demonstrating cost-effectiveness depends on identifying the potential for cross-subsidy within the cost plan. For example, premium costs for high levels of insulation coupled with low-energy heating and a heat recovery system can be subsidised by savings from reduced boiler plant loads.
7 - Undertake cost-benefit analysis
No proposal to enhance sustainability should be judged in isolation since effectiveness will depend on how the buildings works as a whole. Cost-benefit analysis should assess the comparative sustainability impact of proposals and reflect any associated enhancement in development value. Sustainability measures should be prioritised in terms of embodied energy, carbon emissions, energy and water savings balanced with capital and whole-life costs as well as establishing payback periods (see case study, opposite).
8 - Assess whole-life issues
Economic viability should be assessed in terms of whole-life costs. This means demonstrating the potential benefits of increased capital cost in terms of reduced energy consumption throughout the life of a building, minimising occupation costs. Sustainable development also means designing flexible buildings so that they can be easily adapted to future changes of use.
9 - Source and select appropriate contractors
Sustainable development often encourages new methods of construction and working that can lead to increased risk. Successful management of this risk depends on selecting a likeminded contractor with a flexible approach to procurement and waste reduction.
10 - Manage the supply chain
Establishing an appropriate supply chain is particularly relevant to sustainable development where environmental benefits can be achieved through locally sourcing materials and labour to reduce embodied energy.
DESIGN PRINCIPLES
The checklist below gives the key points to consider in design. It covers general good practice and measures that can be taken with no or minimal additional cost and also those that incur some additional capital cost.1 Overarching themes of good practice:
- Use of standard technologies
- Use of systems that occupants can understand and operate easily
- Local sourcing of materials
- Recycling of waste materials
- Use of recycled materials
- Incorporation of design to make recycling easier
- Use of efficient building management systems
- Maximising heat recovery
- Design for greater airtightness of buildings, balanced with fresh air requirements
- Maximising day lighting to minimise artificial lighting, balanced with avoiding overheating
- Control of solar gain to avoid overheating
- Innovative use of solar gain
2 Measures attracting no or minimal additional cost:
- Low-water toilets (indicative premium cost £75/point) and taps (£20/point)
- Good natural daylight/high-efficiency lighting (can be achieved with no additional cost)
- Low-energy white goods (no additional cost)
- Super-insulation to minimise fabric heat losses (indicative premium cost £20/m2 on elevational area)
- Incorporation of natural ventilation where possible (potential cost saving)
- Displacement ventilation in lieu of four-pipe fan coil system (indicative cost saving £20 – 30/m2)
- Thermal mass, allowing heat from the sun or appliances to be stored in the fabric of the building and avoid the expense of mechanical cooling (indicative premium cost £12/m2 on gross floor area)
- Low-emissivity glazing in lieu of increasing cooling capacities
- Light pipes/sun pipes
- On-site remediation in lieu of off-site landfill disposal
- Solar hot water systems (indicative premium cost between £2000 and £5000 per dwelling)
3 Measures attracting additional capital cost:
- Rainwater/greywater/blackwater collection and recycling (additional cost will depend on the specific development)
- Controlled/passive stack ventilation with heat recovery (indicative premium cost £30/m2 on gross floor area for wind-driven ventilation with heat recovery in lieu of simple extract system)
- On-site renewable power generation – combined heat and power systems/wind/heat pumps/photovoltaic cells/fuel cells (additional cost will depend on the specific development)
CASE STUDY: a mixed-use development committed to sustainable design
A major mixed-use development on a brownfield site formed part of a strategic investment programme to regenerate the area in terms of education, enterprise, transport and urban renaissance. The development was a mix of education, residential, business and retail space, together with partially sunken car parking and public realm landscaping.
A key part of the developer’s brief was a commitment to the principles of sustainable design and construction. A checklist provided a framework for assessing the design against this aspiration and helped show the planning authority that sustainability had been systematically addressed. The proposals included the potential incorporation of renewable and/or decentralised energy supply systems.
The comparative sustainability impact of design decisions was assessed and prioritised in terms of carbon emissions and energy savings, balanced against capital cost and payback periods. This was done using the matrix below, which is based on the anticipated carbon and energy reduction per unit of additional capital cost expenditure.
Negative values are shown for increasing thermal mass and glazing performance, indicating that these measures were expected to reduce capital cost (after considering the impact on building services plant capacity). Incorporating these principles was a “no-brainer” because they saved money and enhanced environmental performance.
Increasing building envelope airtightness was the next most effective measure in terms of carbon and energy reductions per unit of capital cost expenditure. The improvement involved spending money up front but this would be recovered through savings in operating costs within 16 years.
Improving solar shading and daylight use were shown to yield comparatively less carbon and energy reduction per unit of capital cost expenditure. The payback periods for these measures were close to or greater than the anticipated building life cycle. On this basis, these measures were considered only where they could be demonstrated to reflect best value.
HOT TOPICS: Policies to increase energy efficiency
The Energy Performance of Buildings Directive and amendments to Part L of the Building RegulationsFollowing changes to Parts L1 and L2 of the UK Building Regulations aimed at increasing the energy efficiency of buildings, a much more comprehensive overhaul of the system will be implemented in January 2006 to raise standards and to transpose and implement the requirements of the EU Energy Performance of Buildings Directive. There are eight key planks in the proposed legislation:
1 Enhanced energy performance requirements will be imposed for all new buildings to conserve fuel and power to minimise carbon dioxide emissions from heating and hot water systems, lighting, cooling systems and fans and pumps; limit heat gains and losses through the fabric of the building and from pipes, ducts and vessels used for space heating, space cooling and hot water storage; and avoid excessive solar gains and thereby minimise the need for artificial cooling.
2 Existing buildings undergoing major refurbishment will now also be subject to energy performance requirements.
3 Carbon emissions for the building must fall within a maximum permitted level.
4 Energy performance certificates must be prominently displayed in all public buildings and by institutions providing public services.
For other buildings, an energy performance certificate must be made available to the owner and user of the building.
5 Operation and maintenance of buildings should be undertaken without causing any more carbon dioxide emissions than are reasonable in the circumstances based on information provided to the building operator.
6 Pressure test and commissioning test results must be submitted by developers.
7 Regular inspections of boilers and air conditioning systems will be mandatory.
8 Renewable and/or decentralised energy supply systems must be incorporated into the design for new buildings over 1000 m2 where technically, environmentally and economically feasible.
This legislation will have far-reaching implications for owners, operators and developers.
Planning guidance
Potential methods of providing renewable energy are wind turbines, solar hot water heating, solar power, ground source heat pumps and biomass boilers. Planning Policy Statement 22: Renewable Energy sets out the government’s planning policies for developing renewable energy resources in England. It instructs planning authorities to promote and encourage the development of renewable energy sources and says regions cannot rule out or restrain renewable energy technologies without sufficient justification and that decisions are subject to government intervention.
Planners must also give significant weight to the environmental and economic benefits of renewable energy projects and cannot make assumptions about the technical and commercial feasibility of proposed developments. The statement also allows planning authorities the option of requiring a percentage of energy used in new buildings to come from on-site renewable energy sources.
The planning strategy for London requires new buildings to incorporate 10% renewable energy generated from on-site sources wherever site conditions make them feasible. Furthermore, the guidance specifies that development not initially incorporating photovoltaic cells should be of suitable design and orientation to enable their subsequent introduction. This guidance is being actively enforced for new developments, and approvals have been refused on the grounds that proposals do not include renewable energy supply systems.
It is important to recognise the implications of this strategy early on in a project because the capital costs associated with generating renewable energy are greater than with conventional power and the cost plan must be established accordingly. Most forms of renewables need to be planned into the scheme from the earliest stages and require in-depth technical feasibility studies to allow full integration.
Source
RegenerateLive
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