Sustainability services

To have the biggest impact every design decision we make has sustainability embedded. It is not something that someone else does, it is something we do each and every day with you.


Alternative view of the apartments from North George Street
Peru Street designed for English Cities Fund is designed to be Passivhaus certified

We can make sure that your project makes a real contribution to resolving our climate crisis for future generations through a curated range of sustainability services and evidence-based design.

In its technical detail sustainable design decisions can and arguably should be complicated. Our aim is to have clear conversations with you about how we can help reduce the impact and improve the performance of your buildings and places. How can we make decisions now that help make healthier, happier, more sustainable and equitable places for everybody?


Our sustainability services

We believe that streamlining the process and offering specialist sustainability services direct from the architectural team just makes sense. It means we are informed and up to date on the latest innovations and technologies, and that this knowledge is written into every decision we make and not just the sustainability report.

Our services are offered in addition to our architectural service and include:

Passivhaus Design Service

Passivhaus is a tried and tested design principle based on sound building physics and backed by over 30 years of international evidence. Its aim is to achieve a healthy, comfortable and stable environment for building occupants. The concept focuses on reducing energy usage, rather than meeting demand by using renewables. 

Adopting a whole-building approach with clear, measured targets gives you confidence in the building’s performance from an early stage. Passivhaus is focused on high-quality construction. The design and build process is closely monitored, ensuring heat loss through the building fabric is reduced and space heating demand is reduced throughout the year. The quality assurance system is backed by a rigorous certification process that guarantees the building will perform efficiently and as promised at the design stage. 

Buttress employs a certified passivhaus consultant and ensures all staff have training in the fundamental principles.  

Passivhaus Planning Package

The Passivhaus planning package is used to assess the energy efficiency of a building through the conventions of the Passivhaus principles. We can review all types of buildings at the design stage, pre-planning or post-planning. The PHPP process will identify the heating and cooling demand per year, as well as the renewable energy demands and gains. This will give you a good estimate of annual running costs. As part of the Passivhaus services offered, design stage thermal modelling can be incorporated to ensure low thermal bridging values and reduce the performance gap seen in more traditional build types. We offer an assessment report post PHPP which provides both the results of the assessment and suggestions for improvement in order to achieve certification standards. PHPP can also be used to assess a building to AECB Carbonlite Silver Standard which has a relaxed standard to the full Passivhaus Certification.

Post Occupancy Evaluation

We recommend conducting Post Occupancy Evaluations on all projects to review occupant satisfaction alongside the energy performance of the building. A Post Occupancy Evaluation can provide evidence of a wide range of environmental, social, and economic benefits core to sustainability. It can also address complex cultural issues such as identity, atmosphere, and belonging.

Interviews and questionnaires can provide rich detailed subjective findings, but a truer picture of occupant satisfaction also requires correlation with objective environmental monitoring of issues affecting comfort such as temperature and air quality.

This data can be collected to various levels of detail, at different times of the year, and once analysed against energy consumption figures, it allows us to suggest improvements to both raise occupant satisfaction and drive down carbon impact.

By learning from past projects and closing the performance gap between forecasted energy use and actual energy use over time, we can continually improve the sustainability and overall success of projects with you.

Embodied & Whole Life Carbon assessment

One of the biggest opportunities we have as designers to reduce the carbon embodied within buildings, and the energy used to run them, is to accurately identify and model their whole life carbon. Life cycle assessment (LCA) is a process for doing just that. By looking cradle to grave and being able to measure the impact of the extraction of raw materials through to the eventual demolition we can make informed decisions throughout the design process and help move towards net zero carbon performance.

We use a tool called One Click LCA which integrates with our Building Information Modelling (BIM) software to quickly analyse and review the impacts of our design choices. This makes carbon assessment an iterative process where materials, massing and orientation are tested and benchmarked as a series of options.

One Click LCA gives us access to a live and verified database of 'environmental product declarations (EPDs) which are mapped against the volumetric data provided by BIM to give us accurate assessments. The assessment is also BRE-approved for BREEAM mat credits and offers compliant reporting based on the RICS ‘Whole life carbon assessment for the built environment’ based on EN 15978.

As a standard – we test all of our projects at an early design review stage against the targets benchmarked by the RIBA 2030 challenge. We understand that the biggest changes to drive down embodied carbon are those which can be adopted at the earliest opportunity. These might be decisions related to form factor, massing, structural grid spacing and building height for example.

We can provide you with a whole-life carbon assessment that goes into more detail throughout the design process allowing you to make informed decisions about how we develop and deliver your project. The report will have a depth of technical detail and easy-to-read visuals for everyone to access the analysis and benefit from it.

Thermal Bridging Modelling

Energy efficiency is increasingly important in today’s sophisticated building designs, and the thermal performance of the insulated building envelope is a key design consideration. A thermal bridge (or cold bridge) is a weak point in the thermal continuity of a building envelope. They are one of the key ways that buildings lose heat through localised weak spots. 

Understanding thermal bridging is critical to designing low-energy buildings. We use THERM software to model the heat transfer effects in building components and details where the risk of thermal bridging is of concern.

By utilising THERM modelling we can assess weaknesses in the thermal line, material choices, and building junctions as the design progresses. The utilisation is bespoke to the project and the principles behind the analysis form part of the technical design review.

ask us about our sustainability services