Sustainability and Energy Design Considerations
Overview of the proposed changes to the updated Building Regulations Part L/F (including SAP 10.1, FHS). Early engagement with policy, regulations and methodology requirements has many benefits (cost, design). Sustainable assessments/ methodologies and their certification can add value.
This CPD event was hosted by Baqus Group Ltd and presented by SRE, a sustainability and energy consultancy. The event was attended by various construction industry professionals and provided an opportunity for networking and learning.
Early Design Considerations
The presentation focused on RIBA Stages 1-3 (preparation and brief, concept design, developed design) and encouraged the early consideration of sustainable design principles to ensure the best design outcome, to reduce the likelihood of costly changes at later stages and to guarantee the cost effective integration of solutions.
Early considerations for building design include site-wide issues (daylight, overshadowing, orientation, site analysis) and building performance (energy efficiency, internal daylighting, thermal comfort, acoustics, ventilation). Simulation software can aid these investigations. Using orientation as an example – maximising solar gains by orientating buildings to South may help to reduce heating demand, especially in summer.
Building Regulations (2020 update)
The building regulations are currently under review – Part L and Part F of the regulations are due to be updated in 2020; SAP 10.1 has informed this update. The Future Homes Standard 2019 Consultation proposes two options to uplift energy efficiency standards and requirements in the new regulations:
- Option 1 – 20% reduction in carbon emissions (compared to current standards) by improving the building fabric only (minimal heat losses from walls/ floors/ roof and triple glazing);
- Option 2 – 31% reduction in carbon emissions (compared to current standards) by improving upon the building fabric (although not to the same extent as in option 1) and incorporating carbon saving technologies (such as air source heat pumps). This is the government’s preferred option.
Architects and designers must be familiar with the local planning policies, which often require an improvement to the standards set by the building regulations. They may also require that contributions be made to carbon offset funds. Energy consultancies can advise on how these improved standards might be met, also where sustainability assessments are needed.
Sustainability assessments which can be used to energy assess and to add value to our designs for the built environment include:
- BREEAM – this is an international scheme providing third party assessment and certification for sustainability performance; early engagement with the scheme is fundamental. SRE have a BREEAM Hub on their website which is a free resource providing BREEAM updates, checklists, design considerations and procedures which apply to each RIBA work stage. Some planning departments may impose a minimum BREEAM accreditation standard, especially for larger commercial developments, as a Section 106 condition.
- WELL Building Standard – this is a standard which supports and advances the health and well-being of building occupants. Like BREEAM, certification is achieved through credits. There are 11 WELL concepts – Air, Water, Nourishment, Light, Movement, Thermal Comfort, Sound, Materials, Mind, Community and Innovation. The ‘Movement’ concept is intended to encourage physical activity, therefore design which encourages occupants to use stairs in preference to elevators may be an important consideration (location, aesthetics). The ‘Mind’ concept realises the importance of mental health in human health and wellbeing and therefore quiet spaces for solitude might be provided.
- PassivHaus – this is a design methodology which is intended to reduce the energy demand of buildings. A well insulated and air tight building envelope minimises heat losses and therefore reduces the heating demand and running costs for the building, while ventilation systems ensure a clean and comfortable indoor environment. Requirements for certification exceed the proposed updates to the new building regulations.
As designers, we should aspire to achieve the best sustainability standards that we can for our buildings, regardless of the minimum requirements set by statute, beginning with improving the fabric standards of our buildings. It is expected that the Future Homes Standard will see a cost increase to projects of around £4-16K (project dependent) compared to the current standards.