Submission by Donald Insall Associates.
Being a good ancestor
Practice
1. Does the practice have a clearly stated purpose aligned with the planetary emergency? We are looking for a bold ambition here, and a practice culture which recognises the need for long-term thinking. For example, a strong mission, a theory of change, or a sustainability roadmap.
Our practice is aligned with science-based targets, aiming to limit global warming to 1.5°C and achieve net-zero by 2045 and receiving SBTi validation for this commitment in March 2025. This commitment shapes our approach across all projects – reducing embodied and operational carbon through material selection, passive design, and the integration of renewable energy and circular principles. We embed carbon accountability throughout the design process, using data-driven tools to measure and reduce impact at every stage. By aligning with robust, independently verified targets, we ensure our work contributes meaningfully to a low-carbon, climate-resilient built environment.
With less than 20% of architectural practices adopting science-based targets, we are leading the way for long-term, impactful change. Additionally, we are investing in new restoration projects across the UK, from regenerative agriculture in East Sussex to social housing retrofits in urban areas. By 2026, we aim for 100% of our projects to be regenerative.
2. Does the practice have a clear succession plan, which passes on ownership and protects the values and legacy of those who built and contributed to the practice? For example is the practice an employee owned trust.
We are embarking on a new chapter with Dorian Proudfoot’s recent appointment as Chief Executive, which marks a significant generational change. With succession in mind, the board of directors is supported by a newly established senior leadership team. The board and SLT mix long-serving (30+ years) directors with a new generation of leaders, bringing fresh rigour with improved communication, professionalism and collaboration.
We were ahead of our time when we began our transition to employee ownership in 1991, when Sir Donald Insall stepped down from the role of Chairman. Decades later, we are now a 95% employee-owned practice. Our track record of social value-led initiatives through training and apprenticeships, and work with educators and local communities has gained us BCorp accreditation in 2024, with a score of 87.0 across five key pillars of Governance, Workers, Community, Environment and Customers, and will build from there.
3. Does the practice share research and knowledge for the benefit of society and the wider world? For example, you regularly carry out post occupancy evaluation and share information with others.
In 2021, we co-authored the Heritage and Carbon report with Grosvenor UK & Ireland, highlighting the benefits of capturing the embodied carbon in historic buildings, calling on the UK Government to address the policy changes, skills and funding needed to make it possible.
Other examples of research and innovation in sustainability include:
Implemented a radical intervention to re-cover the stone wall at Hardwick Old Hall based on English Heritage’s Sustainable Conservation Asset Management Plan (SCAMP) principles, reducing long-term maintenance costs for the client.
Supported the development of the Sustainable Construction and Retrofitting Supplementary Planning Document for Bath & North-East Somerset Council.
Project
1. Does the practice advocate for long-term thinking at the outset of projects? Do you initiate projects with long-term thinking and challenge the client on design life? Also, can the practice demonstrate that this approach has worked – with a shorter or longer design life, or an innovative approach to financing or payback period?
Good design enables the heritage environment to remain viable. Our projects support long-term stewardship of some of the most important heritage sites in the UK, including the Europa Nostra award-winning conservation of Westminster Hall. The decade-long project involved cleaning and sensitive repair work, securing the heart of British politics for generations.
In Pendle, Lancashire, we developed a first-of-its-kind, typology-based design code to enable the redevelopment of its 93 vacant textile mills. The code encourages inward investment while preventing unnecessary demolition, aiming to inspire stakeholders to make the most of their assets.
Keeping a heritage asset viable requires creative thinking. Blencowe Hall, an AT Award finalist in 2024, was transformed from an uninhabitable, roofless ruin into a successful hospitality venue as a single integrated building while boldly expressing its significance. Over 15 years later, Blencowe Hall generated material [an estimated £223,380 per year of additional spending in the Cumbrian economy.
2. Do your projects take account of the future climate and the need for resilience? For example, do the projects demonstrate flexibility, design for adaptation, design for disassembly, non-deterministic solutions, or demountable structures.
Much of our day-to-day work addresses our clients’ need to bolster climate resilience within their heritage sites. One of our most high-profile examples of this is our ongoing work to safeguard Blenheim Palace. This involves restoring a significant section of the palace’s roof, ensuring it is well-equipped to handle a changing climate so this UNESCO World Heritage Site can be enjoyed for generations to come.
At Brighton Museum and Art Gallery, we are helping our client improve their Grade II*-listed site’s thermal performance and reduce operational carbon emissions; establish safer working conditions for maintenance staff; and return a sense of the building’s original architectural intent. This involves a bold move to replace the non-original external roof lantern with an insulated solid lead roof construction which will improve the building’s thermal performance and prevent natural light from entering the gallery below, protecting exhibits.
3. Do the majority of your projects go beyond mitigating negatives and towards optimising positives? For example, are they meeting or exceeding the RIBA 2030 Challenge.
All of our projects aim to actively restore and enhance ecological and social systems. This requires a shift from minimising harm to creating net-positive outcomes–such as improving biodiversity, generating renewable energy, and strengthening community resilience. It starts with a clear, place-specific vision, developed collaboratively with stakeholders, and continues through design, construction, and post-occupancy.
Our Rochdale Town Hall project best exemplified a shared understanding of positive outcomes, which we progressed with delivery partners to empirically prove through post-occupancy evaluation that these had been met. We also use these principles to train all of our technical staff so they can embrace natural systems, use circular and low-carbon materials, and support long-term stewardship. We do not currently adopt the RIBA 2030 Challenge due to client restrictions in historic and secure buildings for post-occupancy evaluation, which we are trying to influence and advocate for.
Co-evolving with nature
Practice
1. Does the practice use biophilia within the office or regularly host meetings and retreats in natural settings? For example do you have extensive planting within the office or rely on natural patterns and imagery for stress relief or quiet areas.
Our annual practice training day is often set within a country estate, with adjacent (usually listed) gardens where we undertake hands-on training with natural materials, such as stone carving, for all staff.
This year, this will take place at Birmingham Botanical Gardens, where we are collaborating with Howells to conserve and revitalise the Grade II*-listed site housing a collection of over 10,000 botanical species – the largest in the Midlands. The proposed scheme has been designed to deliver a low-carbon, sympathetic reinterpretation of the gardens and their structures, with the intention of securing their long-term sustainability.
Closer to home, our London studio is currently undergoing a refresh, where we have designed a workplace retrofit to enable contemporary amenities, such as a shower, in our Grade II-listed building. A part of this scheme is a biophilic strategy for both our indoor and outdoor spaces.
2. Can the practice share examples where it has considered nature in decision making? For example by having a nature proxy to encourage eco-centric decision making, using natural systems as inspiration for the company structure, recognising the seasonal nature of people’s capacity and workload or celebrating equinoxes and solstices together.
One philosophy in working with historic buildings is to interpret them as living objects with evolving needs – while they must be maintained and conserved to stay ‘healthy,’ they may need adaptation for a viable future.
This thinking can be applied to landscapes and plants in historic settings, and we are noticing that this is at the forefront of our clients’ approach to historic landscapes. We know that our buildings need to adapt to climate change in order to continue to function. In parallel, our landscapes are also under threat from the changing environment.
At the Grade II-listed Rivington Terraced Gardens in Bolton, the now ‘wild’ landscape was considered a part of the evolved character of the site. The design team only made essential interventions rather than attempting to restore the more open character of the original garden, which would have led to the loss of biodiversity.
3. Is the practice supporting nature locally and nationally? For example, does the practice support local gardens, gardeners, planting programmes, rewilding programmes or advocate for changes in legislation to protect nature.
One example of this is our pro bono work for the Canal and Rivers Trust. In 2024, we produced a feasibility study to explore how the CRT might adapt Earlswood Pumping Station, a Grade II-listed Engine House, to the Earlswood Lakes on the outskirts of Solihull.
The report provides an initial condition survey, an outline of relevant repair works and sketch plans of potential development options that would help generate further income for the CRT. It also highlights the variety of wildlife around the reservoirs and garden; the report pointed out that there is potential to support the biodiversity and habitats across the site with input from an ecologist, and create a key draw for visitors who wish to appreciate the woodpeckers, kestrels, owls and otters.
Project
1. Can the practice demonstrate projects which strive to match the performance of a mature ecosystem? As a minimum this would mean achieving biodiversity net gain.
Many of our projects involve conservation within buildings and places where the natural landscape contributes to the site’s historic significance.
The Grade II*-listed Camellia House at Wentworth Woodhouse houses some of the rarest camellias in the Western world. Ensuring the longevity of the plants meant protection measures included UV lamps, regular manual watering, bespoke scaffolding, and daily monitoring.
Howells and DIA are collaborating on the £14m ‘Growing our Green Heritage’ project at the Birmingham Botanical Gardens. The 15-acre site, home to heritage assets including four Victorian glasshouses, will be conserved to serve contemporary horticultural needs whilst protecting valuable species.
We transformed Finsley Gate Wharf from a derelict boatyard into a community hub. Adjacent to the conservation project, the Canal & River Trust undertook 3.5km of nature enhancements to the canal. 475sqm of floating reed beds were installed alongside wildflowers, shrubs, and climbers to encourage the growth of new species.
2. Is the practice working on material stewardship? For example, evidence could be shown through repeated use of low carbon materials, extensive material libraries and research or publications supporting responsible use of materials and elimination of waste.
According to the Department for Environment, Food & Rural Affairs, demolition accounted for 61% of the UK’s waste in 2020. As a conservation practice, minimising waste is embedded into our founding philosophy, exemplified by our ISO 14001 and BCorp certification. Our projects begin with research and analysis of a building’s materials, exploring the use of low-carbon materials or re-use where possible.
At Finsley Gate Wharf, we revitalised a derelict boatyard into a leisure destination through conserving multiple buildings, retaining and reusing a large majority of materials. The project was included in the ‘Heritage Environment Forum Heritage Responds’ – taking positive action on climate change report.
At Hardwick Old Hall, repairs to the romantic ruin re-used or used sustainable local materials. Lime putty and quick lime were favoured because of their ability to absorb carbon from the atmosphere as they set, resulting in a carbon-neutral lime cycle.
3. Do the majority of projects demonstrate the use of biologically-inspired approaches such as Bioregionalism, Biophilia, Biomimicry, Ecomimicry (also referred to as Ecosystems Thinking, Industrial Ecology or Industrial Symbiosis) or BioTRIZ?
We do not currently adopt this approach consistently but many of the science-based principles we use for sustainability performance have a grounding in natural systems.
Creating a just space for people
Practice
1. Does the practice have a progressive EDI policy and can you evidence many forms of diversity, which are welcomed and acknowledged, within the practice?
While DIA enjoyed a balanced gender representation at all levels for decades and has a robust EDI policy, we recognise this requires constant attention and vigilance, as well as having an intersectional understanding of diversity. Our Chief Executive, who commenced his role in April this year, said: “For us to succeed, we must continue to embrace a more diverse workforce and ensure our colleagues feel well equipped, supported, valued and rewarded.”
When our senior leadership team was established last year, they undertook rigorous leadership training, which included workshops in inclusive culture-building as a new initiative at DIA. An all-day workshop in Dignity at Work training followed, not only to ensure practice leaders are aware of new legislation, but to reinforce behaviours that will help build a positive culture so that we not only attract but also retain diverse talent. Dignity at Work training has since rolled out across the practice.
2. Does the practice operate a no overtime culture, meet the living wage consistently, and stipulate a fair salary ratio between staff of all levels?
DIA is a Living Wage-accredited employer, including paying the London Living Wage to all staff, and this is a primary consideration when checking our pay levels across the practice. The multiplier between the lowest-paid and highest-paid staff is kept intentionally low.
We take a collegiate approach to overtime as an employee-owned trust. While there are times when overtime is necessary to meet client needs/project deadlines, we are mindful of this, and time spent working is monitored monthly at both SLT and board levels.
3. Does the practice support charities, community groups, social enterprises, action groups and others through pro-bono work, charitable giving or in-kind donations?
We have plenty of examples of this, one of which is the Angel Corbel Workshop with Latymer Primary School for pupils aged 8-9.
Over 60 children attended a DIA-led workshop at All Saints Church, introducing the role of an architect, the church and its key architectural features. The children were invited to design a stone angel corbel to replace an existing corbel, which had fallen from the nave roof due to severe water damage in November 2022. We were introduced by the verger, Irene Mooney, who has been involved with the church for more than 50 years, and then talked through a variety of corbel examples that appear in churches across the country, inviting children to identify common features and take inspiration for their own designs. The children were exceptionally well behaved and receptive to the task; they were engaged throughout and inspired to pursue their love of drawing further.
4. Does the practice publicly refuse to work with certain clients, suppliers or organisations on ethical grounds?
We have an ethics policy which assesses and governs our decisions around working with certain client types or regions. These are considered on a project-by-project basis; our approach is to consider a detailed report by consulting subject matter specialists in order to establish whether or not we wish to pursue the opportunity. A final decision is taken at the highest level of the practice.
Project
1. Do the projects demonstrate deep engagement with local stakeholders and end users? For example, is there evidence that your project engagement goes beyond consultation towards co-design?
Within heritage projects, deep engagement often goes hand in hand with skills training.
The NLHF recently granted £4.7m to renovate Kingsley Hall, which will create purpose-designed spaces for 1625 Independent People, a youth homelessness charity. When we were commissioned to write a Conservation Management Plan, our client asked us to involve young people at every stage of the project. We led three heritage skills sessions with young people exploring the history of the site as well as its national and local significance.
The revitalisation of Rochdale Town Hall involved over 1,086 volunteers from inception to completion, who assisted with conservation, research, cataloguing, archaeology and tour guides. The Bright Hall – once a cramped office space – has been transformed into a community events space featuring community co-created art. Over 280 local people were involved in the art, resulting in 10 pieces of artwork.
2. Do your projects create connected and resilient places which positively contribute to their neighbourhoods and allow equality of access? For example, do your projects create economic opportunity, retain value locally and generate social value?
Our projects are at the heart of spaces that enhance quality of life, support community connections, and improve access to opportunity. Well-designed buildings and public spaces can promote health, inclusivity, and safety, while encouraging social interaction and a sense of belonging. At Rochdale Town Hall, we involved local people in the design process to help build pride and ownership (co-creation) and strengthen community resilience.
By integrating essential services, supporting regeneration, and addressing social inequalities, architecture can play a vital role in creating more equitable, vibrant, and sustainable communities. At the Camellia House, Wentworth Woodhouse, we focused on routes into employment through a series of training and support initiatives. In Rotherham, residents live within the top 20% most deprived areas in the country. The project boosted the local economy by creating 22 hospitality jobs, generating additional revenue for our client, a charity.
3. Do the majority of your projects promote equity in society, and consider all people, not only the building inhabitants? For example, do your projects show due regard for workers within the supply chain and take active steps to avoid modern slavery?
While historic buildings often pose accessibility challenges, we always strive for not only access but parity of esteem. This was our objective for the bold transformation of the entrance of the Royal Academy of Music.
At the Camellia House, Wentworth Woodhouse, we achieved step-free access throughout, an accessible WC and five disabled parking bays. Most significantly, a purpose-built Changing Places facility was installed in collaboration with Muscular Dystrophy UK, one of the first for a heritage site in the UK.
Throughout Rochdale Town Hall, bold interventions unlocked public access to previously inaccessible areas. This includes new terracing around the building and a glass lift within the clock tower to provide level access. <
We require all suppliers and consultants to confirm their adherence to the Modern Slavery Act 2015. Our impact on the wider community and regard for workers within the supply chain scored 21 points within our BCorp certification.