Building Net Zero: Your Questions Answered

Following our popular interactive webinar in June 2022, Building Net Zero: Life Cycle Project Delivery for the Public Sector, we've worked together with our delivery partners and other industry experts to answer your questions on Life Cycle Delivery.

Produced in collaboration with McLaughlin & Harvey, Kier and Morgan Sindall, the Life Cycle Delivery Guide is proving to be an invaluable resource in demonstrating how local authorities can achieve the Net Zero Public Building Standard when delivering new build and refurbishment projects.

What tools can be deployed to assess both embodied carbon targets and budgets for Whole Life (or Life Cycle) costs?

There are several tools available to calculate embodied carbon and life cycle costs. Carbon calculator tools such as One Click LCA and CarboniCa provide whole life carbon assessments.

Morgan Sindall developed CarboniCa in-house to enable project teams to estimate, manage and reduce whole life carbon emissions, in line with the Royal Institute of Chartered Surveyors’ (RICS) professional statement – ‘Whole life carbon assessment for the built environment’ (RICS, 2017).

Third party validated by Arup, the calculator tool includes construction site energy, water consumption and transportation-related emissions, as well as the Environmental Product Declaration certificates for the materials and products installed. It is vital that contractors work closely with PQS Practices who follow RICS best practice to calculate life cycle costs. Ensuring maintenance and replacement of equipment and materials over the building lifespan is included within the carbon calculators and life cycle cost assessments.

Carbon Calculators such as OneClick LCA provide software to calculate both embodied carbon and lifecycle costs associated with a building’s lifecycle.

The Life Cycle Costing (LCC) aspect is based on long-term costs and savings and assesses costs that occur over the building’s lifetime including pre-construction activities such as land purchase, planning and design costs etc., along with construction, maintenance, operation, operational energy and end-of-life related costs. It should be noted, however, that when it comes to Life Cycle Assessment (LCA) or LCC software, these tend to focus on ‘building related’ operational costs such as regular cleaning, maintenance, security, redecoration and repair etc., and typically don’t include for general occupancy and staff costs.

If a more strategic level of whole life costing is required to support capital funding, for example, and needs to include assessment of all predicted occupancy and staff costs, then an LCA/LCC calculator such as OneClick LCA can feed into this to calculate the ‘building related’ whole life costs, however would suggest the use of supplementary tools such as the Whole Life Appraisal Tool for the Built Environment, which is available for use on public sector projects through the Scottish Futures Trust.

What is the additional cost of Life Cycle Delivery compared to 'traditional' costs?

SCAPE and Morgan Sindall recently lead a comprehensive and innovative research and development process which proves how the early alliance of designers, clients, contractors and the supply chain leads to a significant reduction in whole life carbon – known as ‘Circular Twin’. This project asked the question… ‘What can be achieved when carbon is the prime driver of decision-making, ahead of CAPEX?’

As part of an industry-wide collaborative initiative, teams from Morgan Sindall Construction, SCAPE, HLM Architects, Cundall and Lungfish Architects worked together to innovate a new process for designing and delivering construction projects, where reducing whole life carbon is the primary objective. By applying lessons learned from past projects, challenging existing assumptions and utilising vertical collaboration with the whole supply chain.

The project was an 18-month journey, which began in March 2020. The key findings were:

• CAPEX delivered within standard budgetary parameters with multiple paybacks over asset lifetime
• 67% reduction in whole life carbon
• 72% reduction in upfront embodied carbon (48% reduction in lifecycle embodied carbon - achieving RIBA 2030 and LETI 2030 embodied carbon targets)
• 52% reduction in annual energy consumption
• 39% reduction in forest consumption

Would the Life Cycle Contract approach be considered at the early design stage of Passivhaus design in public sector projects?

Yes, the decision to use the Life Cycle contract option must be made at the start of a project. During the free SCAPE feasibility stage, we will work with clients to develop and understand their brief, asking questions such as:

• What operational performance is required by the client?
• What is the end goal?

During pre-construction, we work with clients to develop a viable design, identify in-use performance indicators for the building and set targets against these, considering:

• What energy efficiency or carbon reduction is required?
• What targets can be set with the client?
• What renewable energy is being targeted, and how will it be implemented and reported against, and over how long?

Passivhaus could be a design option considered by the team as a route to achieve the required building performance identified.

Is there a project in Scotland where we'll be seeing the Life Cycle process used soon?

The Life Cycle contract is currently being considered for the delivery of several projects in Scotland.

When will the UK Net Zero Carbon Buildings Standard for Existing Buildings be available?

Scottish Futures Trust and partners have commissioned the advanced documentation and, after a Peer Review over summer, plan to publish final documentation for the Standard for Existing Buildings in Autumn 2022.

Does the retrofit application of the Life Cycle contract work for housing?

Yes, the Life Cycle contract can be applied to retrofit of domestic building. The performance linked contract is ideal for setting a target for energy use (and generation) after works have been completed, ensuring the set energy efficiency targets are achieved – ideal for supporting applications for funding and proving the outcomes of an investment.

Is the Net Zero Carbon Buildings Standard expected only to apply to 'conventional' office or civic buildings? Or is it expected that it will also apply to operational buildings (such as workshops, depots, plant-centric compounds, etc.)?

The Standard applies to non-domestic, new build and major refurbishment projects funded and occupied by the public and the third sector. This includes offices, schools, health centres, etc.

Where the embodied carbon, operational energy or indoor environmental conditions of a project are materially influenced by equipment or process loads, project teams are encouraged to account for these and to make the case for adjustment to the targets and other requirements under the Standard. This could apply to any building category, but examples of those in which it would be commonly expected include acute hospitals, leisure centres and laboratory buildings accommodating ‘industrial’ processes.

Projects which are funded by the public sector but occupied by the private sector could adopt the Standard, subject to project-specific considerations. Broadly speaking, for tenures for which there is no clear approach and commitment to meeting the performance verification and ongoing monitoring requirements of the Standard, it may not be suitable.

How does the standard work in terms of the processes being carried out which are energy intensive (which are not likely to be reduced)?

Project teams are encouraged to request adjustments to the Operational Energy Target for buildings that include energy-intensive processes. This is likely to include treating the processes as Separable Loads, with a targeted performance measurement regime that is separate from the rest of the building. Energy targets for Separable Loads should be based upon best practice.

Where the Project includes the procurement of new equipment associated with the energy-intensive processes, the participant should demonstrate the inclusion of best practice energy performance in the procurement evaluation process.

Where existing equipment is to be retained or relocated to the project building, the Participant should provide evidence that retaining legacy equipment complies with best practice, e.g., including considerations such as embodied carbon and circularity principles – and support any equipment-specific targets with baseline energy consumption and other evidence.

What work is being done to lobby elected politicians, especially councillors, on NZPSB and specifics such as Carbon before CAPEX? Councils are still often making decisions on capital, with limited OPEX and carbon considerations.

The Standard was adopted by Scottish Ministers in November 2020. It is a voluntary standard, designed to assist public bodies to meet their climate change commitments. Local Authorities that have set net zero deadlines are required to apply these deadlines to projects that adopt the Standard.

The Standard is intended to support public bodies to achieve the best value route to achieving net zero operational energy by the relevant net zero deadline. Public bodies are encouraged to exclude solutions that do not meet their net zero deadlines from their shortlist of preferred options for new build and major refurbishment projects. Solutions such as the installation of fossil fuel boilers could cost more in the long term than installing heat pumps from the start, if the cost of retrofitting the building, heating system and heat sources in the future are considered.

Do you support operational digital twins at the post-occupancy and operational project stages for carbon reduction?

Yes, digital twins provide an effective tool for post-occupancy and building performance evaluation.

Monitoring and evaluating building performance provide opportunity to refine and optimise building performance, carry out preventative maintenance and increase the efficiency of the building systems. It also enables in-use energy performance to be compared against design-identifying areas of increased consumption which can be highlighted to the building manager and occupants to actively manage throughout the post-occupancy period and beyond.

The increased capital cost of Life Cycle delivery in public sector projects can be an issue and is often in competition with savings in accounting terms, as their money comes from different funding streams. How can this be managed?

This is a common challenge raised, particularly relevant given the current market conditions. Working collaboratively with our construction partners during the feasibility study, a forecast cost of works can be established to inform those discussions at the outset of the project.

As referenced above, the findings from the Circular Twin project highlighted that CAPEX can be delivered within standard budgetary parameters with multiple paybacks over asset lifetime when shifting the design focus to minimising carbon in lieu of a ‘traditional’ design approach.