Stepwise procedure for designing the low carbon house
Identifying nationally recognized methods for assessing the environmental performance of new buildings in the UK.
Most widely used methods include Code for Sustainable Homes (CSH) 2006 and British Research Establishment Environmental Assessment Method (BREEAM). Other methods include Association for Environment Conscious Building (AECB) Silver and Gold and PassivHaus.
Policies for Sustainable Development in Brighton and Hove
The City Plan Policy CP8 for Sustainable Buildings supported by Supplementary Planning Documents, SPD 08 – Sustainable Building Design is expected to deliver viable development that considers community aspirations, environmentally sensitive, high quality, adequate infrastructure and helps in mitigating the impacts of climate change by gradually transitioning towards achieving a low carbon economy (NPPF, 2012).
National Planning Policy Framework, 2012 expects the local plan policy to play an active role in guiding the development that is viable and sustainable. The principles of One Planet approach have been adopted by the Brighton & Hove City Council which aims at radical reductions in greenhouse gas emissions by reducing energy consumption before the construction and after it is built. Mitigating the impacts of climate change is an important aspect of delivering Sustainable development (Low Carbon Construction, 2010).
Her Majesty’s Government proposed Climate Change Act in 2008 which was the world’s first long-term legally binding framework to tackle the dangers of climate change. It include a statutory commitment to reducing the carbon dioxide emissions by 34% by 2020 and 80% by 2050.
One Planet living principles
It provides a framework that helps us examine and evaluate the sustainability challenges that we face and develop action plans in order to create a sustainable and healthy environment.
The ten principles are as follows:
- Zero Carbon
- Zero waste
- Sustainable transport
- Sustainable materials
- Local and sustainable food
- Sustainable water
- Land use and wildlife
- Culture and community
- Equity and local economy
- Health and happiness
The Passivhaus standards result in the construction of well-insulated, airtight buildings. It utilizes solar energy and internal heat gains from people, electrical equipment for space heating purposes. An energy recovery ventilator is used to balance the supply of fresh air. It has been tested in Europe and America and has had impressive results. It saves upto 90% of space heating costs and also provide excellent indoor air quality.
Passive House Planning Package (PHPP) has been developed by the building science research. It projects detailed heat load, heat loss, cooling loads, latent cooling and primary energy usage for individual building parameters.
Characteristics of Passivhaus
The building envelope ? 0.6 ACH @ 50 pascal pressure, measured by blower-door test
- Space heating requirement ? 15 kWh/m2/year
- Annual energy consumption ? 120 kWh/m2/year
In addition, the following are recommendations, varying with climate:
- Window U-value ? 0.8 W/m2/K
- Ventilation system with heat recovery with ? 75% efficiency with low electric consumption @ 45 Wh/m3
Case study of Denby Dale Passivhaus which is one of the first certified Passivhaus homes in the UK.
Key features of Denby Dale Passivhaus are as follows:
- £141K build costs
- 118m2 three-bed detached house
- Costs/m2 = £1194
- Airtightness: 0.33 ach @ 50 Pa
- Space heating needs: under 15 kWh/m2/annum
- Uses 90% less energy for space heating than the UK average
- Heating costs of around £75 per year.
Below are the steps to designing a low carbon house:
|Intention of the Design Guide|
Climate of Brighton and Hove
|Orientation of the building|
|Building design, construction and low energy specifications|
|Insulation: Active Thermal Insulation
· Walling material
|Windows and skylights|
|Monthly Energy Demand Profiles|
|Suitable renewable energy sources and their monthly supply profiles
a. Ground Source Heat pump
b. Solar Electricity Generation
c. Rainwater harvesting system
d. Mechanical Ventilation with Heat Recovery
e. Annual Energy Balance