Sustainability & Building Physics

What is climate change?

When we talk about climate change, we are referring to the global change in the composition of the earth’s atmosphere caused by humans. This change is created by the release of greenhouse gasses, such as carbon dioxide, from the burning of fossil fuels, deforestation and the manufacture of chemicals, cement and metals. The increase in greenhouse gasses has been occurring since the industrial revolution and has caused the rise of global surface, air and ocean temperatures and acidity levels to rise in turn leading to droughts, polar ice caps melting and sea levels rising etc.

How do we tackle climate change?

The climate change act 2008 made the UK the first country to establish a binding framework to reduce greenhouse gases by at least 80% by 2050 compared to a 1990 baseline. The government has since changed this target to a net reduction of at least 100% of greenhouse gasses compared to the 1990 baseline by 2050. Energy efficiency does not have to come at a sacrifice to comfort and can be via low cost measures on large or small scale, utilising high efficiency boilers, appliances and lighting, using more thermally efficient insulation and better control systems. Increasing energy efficiency is only the first step and must be taken along with a move towards more carbon efficient fuels (such as hydrogen), district heat networks and electric heat pumps to reduce the emissions released while providing thermal energy to buildings.

FHP can provide all the energy and sustainability services required throughout the RIBA stages. Our services include:

• Building physics

• Sustainability Reports

• Building Research Establishment Environmental Assessment Method (BREEAM) reports

• Energy Strategies

• Energy Performance Certificates (EPCs) for Domestic and Non-Domestic Buildings

• Standard Assessment Procedure (SAP) calculations for dwellings

• Level 5 SBEM Calculations

• Daylight Analysis

• Dynamic thermal modelling

FHP’s highly skilled MEP team use the principles of Building Physics to determine the energy use, occupant comfort, carbon emissions and operational performance of a building. This ensures the delivery of buildings which provide comfort whilst optimising energy efficiency.

The behaviour of all buildings is reliant on not only on the technologies implemented but also on the materials used in the building fabric and the orientation of the building. A passive and fabric first approach is used where carbon emissions and energy usage can be minimised before the inclusion of high efficiency HVAC systems.

By modelling the building early in the design process FHP’s engineers can deliver valuable analysis and performance data to ensure passive savings can be maximised. Building modelling informs how the building will function, providing information on heat, air and light transfer through the building prior to completion.

Our capabilities include:

• Dynamic Thermal Modelling

• Level 5 SBEM Calculations

• Daylight analysis

• Lighting analysis

• Heat Loss/Gain calculations

• Energy modelling

Sustainability reports are a common requirement across the UK and demonstrate how a development will comply with local, regional and national policies. These policies will generally cover water efficiency calculations, reporting on flood risk assessments, promote sustainable procurement of construction materials, urban greening calculations, energy efficiency reporting, waste and site biodiversity.

Acting in conjunction with the design team FHP can assist/guide the design evolution of the project to achieve the aims of the local, regional and national sustainability policies.

BREEAM is the world’s leading sustainability assessment method for buildings. Although the BREEAM assessment is voluntary a lot of local authorities now require BREEAM assessments for the non-domestic areas of a project. BREEAM enables the design team to determine the environmental credentials of the building throughout the RIBA stages. BREEAM certified buildings are more sustainable environments and that enhance the well being of the people who work in them; they also help protect the environment & natural resources. There are different codes depending on whether the building is residential or commercial, new or existing.

Energy Strategies are planning requirement for local authorities. They show a route to compliance with both Local and Regional Authority planning requirements, such as The London Plan. They are required to demonstrate how energy efficiency targets will be met, compliance with renewable energy targets and assist with achieving BREEAM ratings. They typically include baseline CO2 emissions, building fabric energy efficiency criteria, building services systems, low carbon technology considerations and final design CO2 emissions. SAP and SBEM calculations form the basis for these reports.

Energy Performance Certificates (EPC) – Domestic and non-domestic

An EPC contains information on a dwelling’s energy usage and carbon dioxide emissions. they contain recommendations to further improve and reduce carbon emissions. EPCs are a legal requirement when constructing, selling or letting a dwelling or non-domestic property.

SAP assessments are the Government’s approved method to produce a domestic Energy Performance Certificate and confirm compliance with Building Regulations Part L. It is the method used to measure energy efficiency and carbon emissions of dwellings. The SAP rating is based on the energy cost of the space and water heating, ventilation and lighting. The calculation requires accurate measurement of the dwellings area and external envelope, including walls, windows, roofs and floors, and data on the heating and hot water generation systems and any renewable systems to be installed. Once the dwelling is constructed in accordance with the SAP specification an EPC is created for the dwelling from the SAP calculation.

FHP are able to provide recommendations and guidance on gaining compliance and improving the energy efficiency of the development.

The Government approved SBEM calculation method is similar to the SAP calculation method, however, it is only for non-domestic buildings. The SBEM calculation produces a BRUKL report which confirms compliance with the Building Regulations Part L2. Once the building is completed and construction has been carried out in accordance with the SBEM specification an EPC is generated via the calculation software.

FHP are able to provide recommendations and guidance on gaining compliance and improving the energy efficiency of the development.

Daylight and Sunlight calculations are increasingly being considered by the local planning authorities. They are carried out during pre-construction stages with the calculation determining the predicted amount of natural light entering a dwelling. Daylight analysis calculations assist with maximising the use of natural light improving comfort, energy usage and environmental quality.

Our range of Daylight Assessment Services include:

• Internal daylight assessment for planning applications

• Daylight calculations for the repealed Code for Sustainable Homes

• Daylight calculations for BREEAM

• Annual probable sunlight hours

• Overshadowing Assessments (Vertical Sky Component)

Overheating is becoming a much more prevalent issue and is certainly something that the local planning authorities are very keen to see the overheating risk mitigated at planning stage. There are many factors that contribute to internal temperatures within building, including:

• Weather conditions

• Location

• Dwelling orientation

• Room type

• Thermal envelope characteristics

• Occupant behaviour

• Local shading and adjacent buildings

It is expected that the south of the UK (London in particular) is likely to face the largest risk of summertime overheating and if no mitigation measures are considered, it is suggested that mechanical cooling could be necessary in all London buildings by 2050.

There are a variety of passive methods that can be considered to reduce the risk of excessive indoor temperatures. Examples of such measures are below:

• Ventilation – Natural ventilation via openable windows.

• Building Fabric – Using high-albedo materials and green roofs.

• Landscaping – Providing Solar Shading

• Preventing solar gains – Via external blinds, solar control glass, inter-pane blinds and internal blinds.

The purpose of a thermal analysis is to assess whether buildings within a development are likely to suffer from an excessive risk of summer overheating. To assess this risk the development will be modelled within a dynamic software suite and a thermal simulation will be run evaluating the performance of the building over the course of a year.

The standard industry overheating benchmarks are found within the texts CIBSE Guide A, CIBSE TM49, CIBSE TM52 and CIBSE TM59, published by the Chartered Institution of Building Services Engineers (CIBSE). These texts refer to thermal comfort within “occupied” areas, which are defined as “areas likely to be occupied by the same person for 30 minutes or more”.