As London leads the way for greener building design, what are the benefits of thinking about Combined Heat and Power (CHP) for inner-city developers looking to be lean, clean, and green?
Prime Minister David Cameron has recently announced plans to regenerate some of the UK’s worst housing estates, replacing them with better homes. With an injection of £140 million, he will of course be looking for the best return on this investment.
He will be looking for evidence of support from the construction industry to meet the targets set out in Construction 2025, which includes a 50% reduction in greenhouse gas emissions in the built environment.
Put that together with the specific aims of the Carbon Plan, you have the government’s aspiration for more environmentally friendly and sustainable buildings, with improved energy efficiency and reduced emissions, and the improved security and reliability of the nation’s energy supply.
Many major UK cities have now launched their own low-carbon economies. And in this respect, the Greater London Authority (GLA) has led with its ambitious London Plan policy, which sets tough targets to achieve the highest standards of sustainable design and construction.
"We need to do everything possible to make the most of our resources, reduce carbon emissions and create a more secure, cost-effective and sustainable heat and power supply across London,” says Mayor of London, Boris Johnson.
Heat loads in buildings generate almost 50% of the UK’s greenhouse gas emissions, and so it is easy to understand why Policy 5.2 of the London Plan focuses on improving the environmental performance of new developments by minimising CO2 emissions; therefore mitigating the effects of climate change over the lifetime of each development.
Be Lean, Be Clean, Be Green
The London Plan message for new building development is clear:
Be Lean: Use less energy – reducing energy demand with sustainable design and construction principles reduces site CO2 emissions.
Be Clean: Supply energy efficiently – designing building services to use energy more efficiently and use low-carbon technologies will further reduce CO2 emissions.
Be Green: Using on-site renewable energy to complement low-carbon energy solutions will additionally reduce CO2 emissions.
Designing greener buildings
Local authority planning applications require details of how a sustainable development will be specifically achieved, for example, through the control of emissions, waste and air quality/pollution, and by using natural resources and building materials.
Planning approval requires the proposed design to comply with the following legislation:
The Building Regulations 2013 Part L: this ensures a design must describe how the development’s CO2 and NOx emissions will be controlled to meet the regulation’s specified limits. These limits can vary by location.
BREEAM: the design must assess specific measures including energy and pollution that affect the environmental impact and sustainability of the building and its future operation.
In addition, many authorities now require a detailed energy assessment for major developments. In London, for example, each assessment must include:
Calculation of energy demand and associated baseline CO2 emissions.
How CO2 emissions will be reduced for example energy efficient design of the site’s building services.
If decentralised energy from heat networks and on-site Combined Heat and Power (CHP) is feasible.
Consideration of other on-site renewable technologies to complement CHP.
Decentralised energy and CHP
A fundamental design philosophy for decentralised energy states that; the more condensed heat demand in the local area, the more cost effective the solution will be. One look at London’s heat density map and you can see why London is expecting 25% of its heat and power used to be generated by localised decentralised energy systems by 2025.
The GLA prioritises decentralised energy wherever feasible, this arises from section 10 of its 2015 guidance document for energy planning, in which it details how developers should investigate the use of heat networks and CHP.
District heating networks have been used in inner-cities and town centres across the UK and Europe for many years. Instead of operating conventional heating, such as individual gas boilers for every property, customers are connected to a common heat source, such as a low-carbon CHP unit. This is accomplished via an underground network of insulated heating pipes. This results in an overall reduction in both primary fuel used, CO2 and NOx emissions.
The types of individual buildings where CHP is generally very economical and its heat and power outputs suit the building profiles include; hotels, hospitals, mixed use developments, food & drink manufacturing plants, leisure centres, prisons, museums, data centres and university buildings especially halls of residences.
By 2025, the built environment will need to show a 50% reduction in greenhouse gas emissions.
Buildings in general will need to incorporate greener designs for long term sustainability.
Developments, especially in inner-cities, will need to prove that they will be lean, clean and green before construction begins.
Low-carbon technologies will increase energy efficiency and reduce emissions.
Decentralised energy – heat networks and/or on-site CHP – have to be considered for all new developments.
Learn how decentralised, low carbon energy such as Combined Heat and Power (CHP) can help your building developments and estates become ‘green’. Download your free eGuide, Deep Green: How criteria for 21st century building performance is testing the environmental credentials of developers and estate managers.
Topics: Building Design