Product specification for architects: Design challenges

The events of the last two years have brought unprecedented transformation to the construction industry. The covid pandemic forced immediate changes, including a rapid shift to working from home and site closures, and is now having a longer-term impact. Companies are evaluating how they will balance home and office working, which affects demand for office space – with consequential impacts on town and city centres. Many people are re-evaluating their home and work priorities, driving a desire for more space, which is affecting established markets such as city-centre apartments. The rapid recovery from the hiatus caused by the pandemic has caused materials and labour shortages, leading to increased costs. Brexit has had an impact too because many European workers have gone home and not returned. The introduction of full custom controls on the movement of goods between the UK and EU in January 2022 could further lengthen lead times. And the introduction of the UKCA product mark in January 2023 could cause disruption to the manufacturing sector because of the costs and limited testing facilities needed for the new certification.

Net zero targets, which are being enthusiastically embraced by the development community, are focusing minds on the environmental impacts of construction – including, for the first time, embodied carbon. Whole-life carbon assessments, which evaluate the upfront, operational and end-of-life carbon impacts, are increasingly being requested by clients and are now a planning requirement on larger schemes in London. In turn, designers are asking manufacturers for environmental product declarations (EPDs) and factoring the environmental impacts of product manufacture into their specification choices.

The combustible cladding ban, introduced since the Grenfell disaster, has had a big impact on facade specification and is also affecting structural material choices. And the Building Safety Bill, which is going through the legislative process, will change the way tall buildings are designed, delivered and operated.

This report identifies the changes and assess the impact these are having on architects, specifically on their specification choices. It also looks at levels of knowledge within the profession, where architects go for information, and how the manufacturing sector can help architects make more informed specification choices.

The survey – who are its respondents and what sectors do they work in?

Building Design surveyed its readers to get a better understanding of the pressures on architects, how they are responding, and the type of information and reassurance they need to make specification choices. More than 300 architects, from firms with fewer than 10 staff up to large practices with over 50 architects, responded to our survey. These are firms that work across sectors from education and healthcare, to infrastructure, commercial and sports and leisure. There are also practices specialising in historic buildings or in civic and community buildings. Private housing is the most worked-on sector among our respondents, which is a reflection of the long-running housing boom as well as being related to the fact that more than half the respondents work for firms with fewer than 10 architects, which tend to focus more on private housing work.

The challenges facing architects

The central role played by architects on projects means they are under pressure from all sides. They must liaise with clients and other consultants as well as contractors, and they must negotiate the planning system, building and other regulations, in addition to ensuring that the buildings they design look good, function effectively and are energy-efficient and durable.

Our survey reveals that architects are indeed grappling with all these issues: in answers to an open question, architects said their number one design challenge is meeting the net zero agenda, which is cited as the top issue by 27% of respondents. The specifics of meeting the targets are exercising architects, with the key challenges including how to work out the embodied carbon impacts of materials, the whole-life carbon assessments of designs, energy calculations, achieving BREEAM ratings and retrofitting. Some respondents flagged that this is made more difficult by the need to do calculations quickly and at an early stage in projects. Keeping clients, who aspire to low carbon buildings, on board once they realise there is a premium to be paid is cited as another challenge.

Several architects, particularly those from larger practices, mention the challenge of meeting fire safety requirements on tall residential buildings, with others saying that meeting regulations in general is difficult. Inevitably planning is a source of irritation, with the greatest ire reserved for slow and conservative planning departments. Cost comes up as an issue too, whether this is general budgetary pressures, clients wanting to spend the minimum, or cost-cutting contractors. The cost of materials and in particular price increases is also a big challenge.

What are the issues affecting building design?

When asked what the main design trends are, in an open question, 47% of respondents said sustainability. The remaining responses cover a wide range of issues, with fire safety being mentioned by 6% of respondents and modern methods of construction by 4%. Other topics cited include integrating artificial intelligence into buildings, the increasing complexity of construction systems, and the pressure to reduce costs.

In terms of sustainability, several respondents mention the need to consider refurbishment carefully before opting for demolition and new-build. The sustainability of materials crops up repeatedly; this includes using materials and products with low embodied carbon and reusing and recycling these too. Energy efficiency is a second key sustainability topic, with references to increased insulation, heat pumps and techniques such as Passivhaus.

The winners of Building Design’s Architect of the Year Awards also stress the importance of sustainability in their work. Allies and Morrison, winner of the Higher Education of the Year category for its student accommodation buildings at Oxford and Cambridge universities and the Sir Michael Uren Hub, a science research building, says it prioritises passive design measures including efficient MEP and fabric performance. The practice’s Cranmer Road student accommodation scheme in Cambridge for King’s College was the city’s first major Passivhaus project. Both its student accommodation schemes featured CLT frames.

Stiff + Trevillion, the winner of Office Architect of the Year, says the practice has always chosen a palette of colours and textures that sit comfortably with neighbouring buildings but now the priority is the provenance and carbon footprint of materials. The practice says a particular challenge is maintaining early enthusiasm for sustainable buildings through to completion, given the cost premium.

Gold Award winner Feilden Fowles says it is committed to the selection of robust, long-lasting and locally sourced materials including reduced-cement concrete, timber, natural stone and the use of lime mortars. Refurbishment Architect of the Year winner Feilden Clegg Bradley highlights the use of its whole-life carbon assessment tool on its winning projects, which informed decisions whether to repair or replace existing elements.

To gauge how specification choices have changed over the past year, we asked our respondents to state the degree of change experienced across a range of key issues including building safety, net zero, building regulations and the impacts of the pandemic.

To what extent have changes to the following impacted on architects specification choices in the past year?

Overall, the zero carbon agenda has had the biggest impact on the profession over the past year despite the challenges posed by the pandemic. Building regulations are reported as undergoing the second-biggest change, followed by building safety. Market pressures languish as the issue having undergone the least amount of change – probably because there is always the pressure to deliver as much building as possible for the least amount of cost.

In terms of practice size, zero carbon has undergone the most change for practices with fewer than 10 architects and for those with more than 50, whereas firms with 11-50 architects report that materials shortages have undergone the most amount of change, followed by regulations. Large firms report that building safety has been the second-biggest source of change, possibly because they are more likely to work on high-rise residential buildings.

When it comes to how architects anticipate these issues changing over the coming year, zero carbon still tops the list, with building regulations in second place. If anything, architects expect the situation with materials shortages to worsen, as this displaces building safety which drops into fourth position. Unsurprisingly, the impact of the pandemic drops to the bottom of the list, given the success of the vaccination programme and because most people have now adapted to hybrid ways of working.