Optoppen is an innovative construction method designed to address the challenges of urban densification by adding lightweight, low-carbon roof extensions to existing buildings. The approach is rooted in the concept of “topping up” — using the space above existing structures to create additional floor area, maximizing the potential of existing buildings. This sustainable strategy helps to meet the growing demand for housing and office space in urban areas while significantly reducing the environmental impact of traditional development.

A key component of this solution is the Optoppen Web Platform, which offers an easy-to-use tool for building owners, developers, and city planners to assess the feasibility of adding storeys to their buildings. This dynamic platform allows users to model the vertical extension potential of their existing structures, providing real-time data on the additional floor space that can be added, the carbon savings achieved by using timber, and the overall environmental impact of the project.

The Optoppen tool incorporates various parameters, such as building type, structural conditions, and local planning regulations, to deliver a tailored assessment of each project’s potential. This feature helps users understand the limitations and opportunities of their existing buildings and enables them to experiment with different configurations, optimising designs before making any commitments. The tool also highlights the embodied carbon savings of using timber for the new extensions, further reinforcing the environmental benefits of the approach.

On the Optoppen website, stakeholders can access a comprehensive database of case studies, policy insights, and best practices from across Europe. This knowledge hub helps guide the decision-making process by providing detailed examples of successful projects, along with valuable lessons learnt. The platform also fosters a wider conversation on policy and regulatory frameworks that support upward extensions, addressing any potential barriers to implementation.

By focusing on existing buildings, Optoppen presents a practical solution to urban housing and office space shortages, offering a cost-effective, low-carbon alternative to demolishing old structures and constructing entirely new ones. The approach supports the efficient use of resources, reduces construction waste, and contributes to the revitalization of older urban areas. As cities continue to grow and face mounting pressure to meet housing demands, the Optoppen approach provides a scalable and sustainable way to enhance the built environment, all while adhering to carbon reduction goals.

A wide range of solutions exist which can facilitate the creation, storage, and use of materials passports, making it easier for manufacturers, designers, and owners to store and reference valuable information about the composition of their products and buildings. Many of these solutions can help collect key product and sustainability information including data from EPDs, health and wellbeing information, circularity metrics, and more. Additionally, materials passports can include information related to the manufacture, testing, and warranty of products to enable better due diligence and improve insurability.

These solutions can facilitate the creation of materials passports at a variety of levels from individual materials and products to wider building systems. Many also provide some level of interoperability with other digital tools like BIM, LCA calculators, digital twins, or digital reuse hubs. By utilising these solutions, valuable information can be better collected and utilised across the built environment supply chain to encourage more sustainable and circular decisions in the future.

Minoro is a free online resource providing access to over 1000 guidance and resources for managing carbon reduction in buildings – the first time this information has been collated and centralised. Developed by Grimshaw in collaboration with over 20 supporting organisations includingÌý,Ìý,Ìý, theÌýÌýand several national Green Building Councils from across the globe, Minoro, links the resources to a series of actions that will decarbonise new and existing buildings.

By collating the bestÌýinternational and regionalÌýresources and guidance in one place, Minoro makes navigating and delivering carbon reductionÌýmore achievable.ÌýAdopting the actions set out in the platform will help to unlock opportunities and outcomes and provides a stepwise approach: a carbon management toolkit is also available for download to support live projects.

Curated by experts from across the built environment and construction value chain, the platform is designed to help and be accessed by asset owners, investors, design teams, consultants, contractors, and building operators. The information is organised into different actions which can be sorted by region (including the UK, EU, and seven other countries with more including Ireland to be added), by project stage (from pre-design to end-of-life), or by core activity or stakeholder.Ìý The content is regularly updated ensuring that the most relevant guidance is available and feedback for improvement or input is welcomed through the platform.

The End Cat A campaign is a group of people working in the built environment sector striving to end waste from office fitouts. The campaign includes designers, architects, contractors, developers, recyclers and more united by a belief that Cat A fit-outs are anachronistic. The campaign works to reduce waste from Cat A fit-outs via a number of methods. They share examples of best practice and can provide contacts to the growing number of companies who recondition used lights, test, and warranty them. They also give information on the thousands of new and nearly-new commercial luminaires that are available for free on reuse websites. Additionally, the End Cat A campaign shares details of clearance firms which re-home used lights. Their role is to bring attention to the issue to increase the implementation of practical solutions.Ìý

Leading developers are already adopting best practices to reduce waste from Cat A fit-outs. By installing only sample floors, they can significantly reduce the number of luminaires installed before tenants move in. Another option is to design architectural lighting and ceilings for retention by making the installations more considered and creative. Designing the electrical infrastructure to easily facilitate modification would also enhance retention.ÌýÌý

Anyone interested can join End Cat A or sign their pledge to show their commitment to ending Cat A waste. By giving inspiration and advice, the End Cat A campaign is working to ensure that no luminaire ends up in a skip.Ìý

Cerclos provides organisations with robust tools to effectively and efficiently assess and mitigate the environmental and cost impacts of building and infrastructure projects worldwide, spanning the entire project life cycle. This encompasses providing a centralised platform that enables stakeholders to seamlessly gain a comprehensive overview of their project’s environmental performance, from macro to granular levels, at any project stage. Teams are empowered to compare alternatives, catalyse innovative sustainable designs and strategies for real-world implementation, and approach decarbonisation holistically and transparently, beyond simply meeting reporting requirements.

Cerclos’s flagship whole life carbon assessment software, eTool, streamlines the whole life carbon assessment process for building and infrastructure projects worldwide, ensuring precision and efficiency. It is a collaborative solution for organisations to measure, improve, and report on the whole-life carbon emissions of their building and infrastructure projects, aligning with international standards and rating schemes such as BREEAM, PAS 2080, Level(s), London Plan, Green Star, LEED, Living Building Challenge and the new RICS 2^nd edition.

eTool provides comprehensive insights for informed decision-making, helping users minimise environmental impacts, and it has more than 10,000 users globally. Its flexibility allows it to model projects of varying scales, from residential homes to commercial buildings and large infrastructure projects. eTool allows users to analyse various aspects of a project’s design and operation, identify the most significant sources of emissions, and explore alternative, more sustainable options. Compared to spreadsheet-based approaches, eTool is a collaborative tool equipped with high quality data sources and robust capabilities including templates, a portfolio emissions analyser, API integration, automated reporting, and scenario modelling.

Thanks to its unique and efficient template system, eTool simplifies the process, offering pre-built or customisable templates that gather related elements in one place, ensuring repeatable, accurate and comparable assessments and more geographically relevant results. This streamlining enables project teams to simplify project take-off information and LCA data input to gain deeper insights into the construction make-ups and efficiently identify hotspots across different stages. Users have the option to build their library of templates or use the existing library, which includes thousands of templates for construction components, energy and water use, benchmarks, and more. Its scenario pioneering feature allows users to compare alternatives quickly from early-stage modelling to detailed impact analysis, finding optimal improvement strategies at the lowest cost. While eTool can function as a standalone solution for life cycle assessment, it can be used in connection with other solutions such as AutoCAD and BiM model, but its effectiveness as a standalone solution provides a more comprehensive approach to sustainable construction.

On the assurance front, Cerclos further supports eTool users with third-party design certification to ensure high-quality LCA studies.

Leveraging eTool offers significant benefits for teams and projects including long-term savings, increased project value, and achievement of sustainability goals. While cost-benefit ratios vary by project scale and user case, eTool’s robust capabilities ensure top-tier LCA studies, fostering sustainable results, and catalysing design innovations, crucial for short-term and long-term project success.

The New Model Building provides a detailed methodology for designing multistorey mass timber buildings in the UK, which meets current guidelines and has the support of insurance companies and warranty providers, increasing confidence in the use of mass timber. The model has been produced by Waugh Thistleton Architects, alongside fire engineers from UCL, structural and sustainability engineers from Buro Happold, and cost consultants from Gardiner & Theobald.

The guidance is divided into a suite of three open-source and easily navigable documents:

• The Guide Book explains why the New Building Model is needed and what it includes
• The Detail Book describes the technical standards used to create the model and includes a collection of construction details, checklists, and performance specifications
• The Evidence Book contains the pre-assessed documents submitted to the national warranty provider NHBC.

With this comprehensive array of information, the New Building Model allows for stakeholders including designers, developers, insurers, and investors to have clarity and confidence to incorporate mass timber into their multistorey residential projects. The framework uses a typical building to show how the details and design principles can be used and is meant to showcase a methodology for timber residential developments in a climate emergency. Included in the guidance is also a detailed moisture management plan, fire strategy principles, acoustic performance information, and construction sequencing.

The New Building Model was developed with the following design parameters:

• Buildings with a height of less than 18m (around 6 storeys)
• Complies with all current Approved Documents and Building Regulations
• No combustible materials used in the external walls (to achieve an EWS1 Form and meet GLA funding requirements)
• Fire compartment in line with REI 60 and K2 60
• Best practice waterproofing and moisture prevention and mitigation
• Mass timber elements including glulam columns and beams, LVL columns and beams, CLT walls and slabs.

A whole life carbon assessment (A-C) was completed for an archetype New Model Building of six stories and 29 flats. Material volumes were calculated from a BIM Model and manufacturer EPDs, and the archetype achieves an A+ LETI rating and results in a carbon savings of 74% compared with an equivalent concrete and steel building. The Model Building would also be quicker to build, as timber frame construction typically can be delivered in a third of the time of traditional concrete framing. Additionally, timber construction is safer, quieter, and requires fewer deliveries. Excluding sequestration, the New Model Building has estimated upfront embodied carbon (A1-A5) of 326 kgCO2e/m2 and total embodied carbon (A-C) of 271 kgCO2e/m2 which meets the RIBA 2030 Built Target.

The New Model Building is intended as a set of design principles prepared for Build by Nature. This guidance meets the current UK Building Regulations and NHBC technical standards but was not intended to relieve any consultant of their responsibility to ensure designs meet suitability, performance, and compliance requirements.

Circular Passports®

Upcyclea® has already developed nearly 10,000 passports for a variety of materials and products. Information about their composition, recycled and bio-based content, reuse potential, and LCA is input directly from the manufacturers via free access to the platform.

Pictograms are used to allow for material data to be easily compared across products, and all information is qualified and rated by Upcyclea’s experts. Proven third-party information is highlighted with coloured pictograms and self-declared data is greyed out. Project or facilities management teams can also use the Upcyclea platform to create specific passports based on existing materials where no manufacturer data is available.

Circular Signature®

By integrating the data from multiple Circular Passports®, Upcyclea® can create a Circular Signature® for a given building. This signature can measure the degree of circularity, embodied CO2 footprint, material health values, as well as the residual economic value of a building which can be determined using the its products and materials based on recycling or reuse marketplace prices within the UK. This allows for detailed insights to be recorded at both the project and portfolio levels and allows project teams to set targets as well as manage and monitor in real time based on any changes to project materiality.

Digital Bank of Materials

When applied to a large building portfolio, the data aggregated by Upcyclea® can be used to develop a digital bank of materials, in line with the EU’s Buildings as Material Banks initiative. This allows for local authorities, developers, and property managers to more fully understand the resources contained within their buildings to better facilitate their eventual reuse. With detailed information regarding the quantity and quality of products and materials, sustainable deconstructions can be adequately prepared for, long-term economic value can be managed, and waste can be avoided. The platform also allows for existing buildings to be effectively deconstructed by allowing existing materials to be uploaded directly from pre-demolition or pre-refurbishment audits.

Reuse Library

It is essential that viable marketplaces for the trade and transfer of materials exist in order to spur reuse and Upcyclea® also features a robust reuse search engine, Noah which can help to correlate the supply of materials available for reuse with demand. When deconstructions alone cannot fulfil this demand, in-situ products can be sourced from alternative marketplaces, material depots, and other resource partners. Upcyclea have also developed the UK specific platform ROMULUS for driving large scale reuse among public and private organisations.

Natural Building Systems has developed a construction system made with biogenic materials to address embodied emissions, operative emissions, and the waste associated with construction. Their system includes lightweight, breathable insulated wall, roof, and floor panels, which are standardised and designed to be efficiently assembled on site and easily disassembled and reused. Natural Building Systems’ primary innovation is the integration of HempSil, a natural insulation made from hemp, with demountable structural cassettes. During its growth, hemp absorbs up to 14 tonnes of carbon per hectare annually and is a good crop to incorporate into sustainable field rotation strategies. When used as an insulation material, hemp absorbs and desorbs moisture in the air, regulating indoor relative humidity and temperature.

The system is also well suited to address other problems typically attributed to the built environment. The panels themselves are self-similar to reduce costs and waste during production, but they can be combined with each other and bespoke components to provide a great amount of flexibility in design. Natural Building Systems’ panels can be delivered flat-packed or pre-assembled depending on the project needs. Assembly and disassembly are both quick and easy due a patented method of securing panels together using timber pegs and T&G cones. This method also allows reconfigurations or alterations to be made without waste.

Natural Building Systems are committed to the circular economy and even provide BIM material passports for all their products. Currently, this system is limited to 11m high buildings for residential use in the UK, but for non-residential uses it can be used for structures up to 8 stories high when paired with a timber structure.

Graphenstone Ambient Pro+ changes the nature of paints, from synthetic oil-based toxic off-grassing coatings to active air-purifying, natural mineral based products. It is a high-tech, modern paint made from traditional materials, with no performance compromise yet offering actual health benefits along with an unsurpassed sustainable and ecological profile. The paint has a mineral matt finish significantly enhancing the overall design of all interior spaces.

This lime-based coating actively cleans the air, every day, using light energy from sun or ambient.ÌýIt removes air-borne toxins such as NOx, SOx, as well as removing CO2, the majority in the first 30 days after application.

It also offers an extremely low carbon footprint (certified by Solingesa), relative to other synthetic brands, whilst absorbing CO2 in volume, during the curing phase, in the first 30 days after application (circa 5kg per 15 litre pot). This is a natural process and part of the scientifically recognised ‘lime cycle’.

The embedded carbon footprint of Ambient Pro+ is also one of the lowest in the industry, a fraction of the levels of other mainstream synthetic plastic-based paints brands.

Furthermore, this mineral paint contains no plastics, micro-beads or man-made chemicals. It’s natural mineral base has been strengthened with Carbon Graphene, the strongest material on earth and a Nobel prize winning 21st Century discovery. This also ensures Class 1 washability for this ultra-clean paint.

Ambient Pro+ is certified Gold by Cradle to Cradle Institute, Global Green Tag, and Eurofins Indoor Air Comfort Gold.

Graphenstone Ambient Pro+ is a comparable price to other ecologicalÌýpaints on the market, and when its superior coverage is taken into account it works out towards the cheaper end of the market.

The HTS Stockmatcher is a free web-based selection tool for the procurement of reclaimed steel for use in new construction projects.

The system compares two lists of information: a list of reclaimed steel, and a list of design steel. It finds where design elements may be substituted with reclaimed elements. The matching process considers geometric and simple structural properties, along with the waste produced through offcuts and over-specification. The Stockmatcher reviews all suitable substitutions and returns the most efficient matches. The hope is that it will facilitate the wider adoption of reused steel, accelerating practical application of circular economy principles and help to reduce the industry’s significant carbon footprint.

The tool is free to use.