New Premises

It is important that the specification, design, and construction of all new premises take account of the projected impacts of climate change over their planned lifetimes in the context of their geographical location and site-specific conditions. Typically this will require consideration of climate threats and opportunities for periods in excess of 30 years. Given that the uncertainties of climate change projections increase with time, one of the important design criteria is likely to be flexibility to cope with a range of future climate risks by, for instance, options for incremental upgrading of adaptation measures.

Many of the issues and adaptation responses for new build are similar to those for retrofitting, although the clean slate should allow many to be implemented more readily. In addition there are a number of opportunities for new build that are unavailable or impractical for refurbishment projects. Some of these are considered below:

Site selection

Although there is unlikely to be complete freedom in the allocation of sites for new premises it is important to consider site specific climate risks when selecting the location of any new developments.

• Where possible avoid sites that are currently vulnerable to flooding, or are likely to become vulnerable as a result of projected climate changes over the design lifetime of the planned development. See climate risks to premises for more details on types of flood risks. The Environment Agency should be able to advise on risks of fluvial and coastal flooding. Specialist advice may be required to assess risks of surface and ground water flooding.
• Highly exposed sites may increase risks of storm damage and overheating in periods of high temperatures, although higher average wind speeds may increase natural cooling and offer greater opportunities for passive cooling
• Sites on south facing slopes and in dense urban areas are likely to increase vulnerability to high temperatures and restrict opportunities for passive cooling.
• Site typography and soil conditions should be considered in relation to flooding and risks of erosion and slope instability

Appropriate adaptation measures should be considered to mitigate any risks arising from site specific conditions.

Site layout

Wherever possible, the layout of the components of the development should be designed to minimise climate threats and maximise opportunities arising from the location and site specific conditions. Considerations should include:

• Orientation of buildings, position of glazing and landscaping schemes should be designed to maximise solar gain at low sun angles in winter and to minimise solar gain during hot summer months.
• Site layout should be designed to minimise on and off site flood risks using SUDS techniques. Where possible win-win solutions should be sought by appropriate layout of buildings and landscaping to minimise flood risks and enhance the amenity and biodiversity value of the site.
• Landscaping and planting should be designed to provide adequate shading for buildings (particularly to southern aspects) and outside spaces. Planting schemes should to be resilient to projected climate changes, particularly drought conditions, and should designed to minimise the need for watering.
• Impermeable surfaces should be avoided where possible, particular where there are risks from surface water runoff.

Design and construction

The design and construction considerations for new build are similar to those discussed for retrofitting. Typically, most should be easier to integrate at the construction stage than to retrofit, including:

• Sizing of gutters, down pipes, and drainage systems to cope with more intense rainfall
• The use of green roofs
• Location of electrical systems to minimise risks in the event of flooding
• On site flood defence measures

Design to optimise thermal performance in both hot and cold weather by:

• Choice of materials offering both good insulation and high thermal mass
• the sizing and positioning of glazed areas to maximise solar gain during cooler seasons and to minimise gain during the summer.
• Utilising opportunities for passive cooling
• internal layout and functions to maximise benefits of natural heating, cooling and light.
• The use of roof overhangs, external shading, or brise-soleil to minimise solar gain at high sun angles.
• The use of smart glazing materials and automated shading systems
• The use of light-coloured and reflective surfaces for walls and roofs to minimise radiant gain.
• The use of green walls and climbing plants on external walls to produce shade and evaporative cooling.
• Ground source heat pumps are an energy efficient means of heating and cooling, but require extensive groundwork for installation and large internal radiating surfaces, typically floors, to convey heat. Hence, they are most cost-effective if installed at the construction phase.

Opportunities for Rain water harvesting and grey water recycling, including installation of separate grey and potable water systems, as water conservation measures.

Sources of advice

Adapting to climate change: a checklist for developers
Adapting to Climate Change: A Case Study Companion to the Checklist for Developers
TCPA publication Adapting to climate change by design
NHBC Foundation Climate Change and Innovation in House Building: Designing out Risk.
Urban Design (Spring 2007, Issues 102) focuses on the topic of adapting to climate change.
The National Centre for Excellence in Housing provides some guidance on sustainable housing, although here is little specifically about adaptation to climate change.

Some relevant planning sector guidance:

Planning Policy Statement 1: Delivering Sustainable Development
Planning Policy Statement: Planning and Climate Change - Supplement to Planning Policy Statement 1
Planning Policy Statement 3: Housing
Planning Policy Statement 25: Development and Flood Risk

Examples