Blog: Nowt Haus – Less is More
In this blog, Madelaine Bradley introduces Nowt Haus: a “less is more” approach to designing comfortable, resilient buildings with reduced reliance on mechanical systems. She explores how occupant choice, passive design and a fabric-first strategy could improve performance, cut costs and carbon, and create simpler buildings that work with the climate.
What if… instead of asking what systems a building needs, we asked what conditions people actually need to feel comfortable?
Using comfort as a baseline as we have been doing for centuries, we can aim for buildings that don’t depend on mechanical systems at all. Nowt Haus grows on the principles of PassivHaus and works with the climate to temper the outdoor conditions, giving occupants greater control, which boosts satisfaction.
Rethinking comfort
Conventional offices are often designed to maintain a narrow temperature band, typically around 21°C to 24°C, depending on the season. Achieving this consistently can require extensive heating, cooling and ventilation systems, whilst many occupants will remain unsatisfied.
Comfort is not determined by air temperature alone. Air movement, radiant temperature, clothing, activity and personal preference all influence how comfortable someone feels. People can tolerate a wider range of temperatures when they have agency over their environment.
Operable windows, local fans, and the ability to move within a space can all improve occupant satisfaction. Designing a space to provide comfortable temperatures in all but extreme weather conditions may be a better fit for some properties than installing complex, demanding systems to maintain a fixed temperature year-round.
Reducing mechanical dependence
Mechanical and electrical services can represent 15–45% of a building’s construction cost. They also require ongoing maintenance and eventual replacement, and when they fail, the entire building can become unusable.
Nowt Haus proposes buildings should remain reasonably comfortable even when active systems are unavailable, and the systems that are used, are smaller and used more intelligently. This will offer benefits such as greater resilience, lower construction or commissioning time, lower maintenance, repairs and replacements, all whilst freeing up ceiling spaces and services risers to add ceiling height and usable floor areas respectively.
Fabric first
The Nowt Haus approach relies on the building’s form, fabric and controls doing more of the work. We can re-allocate funds saved in MVHR and reallocate across the project.
Exposed thermal mass, such as a concrete floor, can absorb heat during the day. Night-time purge ventilation can then remove accumulated heat using cooler outdoor air using roof vents or high-level windows for safety. Solar-control measures such as shading and low g-values limit unwanted heat gains, whilst wide opening areas introduce fresh air.
A hybrid structure could combine exposed concrete, where thermal mass is beneficial, with lower-carbon materials such as cross-laminated timber elsewhere. Each solution would need to be tested against operational performance and upfront embodied carbon. We can offer Overheating assessment in line with CIBSE’s methodology to ensure the combination of strategies maintains a comfortable thermal comfort level.
Controls could combine automation with manual override. Vents might respond automatically to temperature and carbon-dioxide levels, while occupants retain the ability to open a window, balancing dependable background performance with personal choice.
Designing right from the get-go and cultural change
It is important to consider form factor and context in the design as early as possible. Open-plan workplaces are generally more compatible with shared natural-ventilation strategies than cellular buildings, where enclosed rooms can restrict airflow and cross-ventilation. These principles therefore need to shape the architecture from the outset rather than being added after the layout and façade are fixed.
Retrofitting existing buildings presents technical challenges, but the greatest barrier may be cultural. Project teams frequently over specify mechanical capacity to avoid providing too little. An alternative could be to monitor a modular system, which could have additional capacity added should monitored performance show it is needed. This is dependent on the client as it may not be suitable for significant additional works to be added post-occupancy once the landlord has leased the building and may be more attractive to owner-occupiers. They have a direct interest in long-term energy use, maintenance costs, resilience and occupant satisfaction, balanced with the potential cost savings using a modular approach.
The next steps
The next stage for Nowt Haus is for academics and industry professionals to test the concepts through detailed façade, window and airflow studies. Further embodied-carbon analysis will be needed to ensure that passive performance does not depend on unnecessarily carbon-intensive construction.
Cost, compliance, construction time and commissioning must also be considered. A simpler building may require more thought at the design stage, but this could be offset by fewer services and easier long-term operation.
Nowt Haus is not about doing nowt! It’s about doing no more than necessary. Could this concept apply to your next project?
About the author
Madelaine Bradley is an Architectural Technologist at Bowman Riley, with a degree in Architectural Design and Technology and a distinction-level MSc in Environmental Design of Buildings. She specialises in sustainable, low-carbon design.