About

Evergreen Design Studio was established by Heather Johnson (McNeill) and operates in and the Hertfordshire area

Heather runs this business alongside her work as a Director at A D Practice Ltd in Wheathampstead.

Heather is a fully qualified architect registered with the ARB and RIBA, a Certified Passivhaus Designer and an AECB CarbonLite™ Retrofit Foundation Graduate. She was part of the RIBAJ 2024 Rising Star cohort in recognition of her work in the sustainability field and a runner up in Passivhaus Trust Awards 2023.

Heather is a graduate from both the prestigious Architecture course at the University of Bath and the only sustainability-led architecture course in the UK based at the Centre for Alternative Technology in Wales.

Born and raised in Hertfordshire, Heather has extensive local knowledge and experience gained as part of her work as a Director at A D Practice Ltd in Wheathampstead. She has also worked for a period in Suffolk and so is well versed in more rural schemes as well as the many planning intricacies that arise in the planning process around Hertfordshire, particularly Greenbelt issues.

Drawing on expertise and understanding of sustainable design and healthy living environments, Evergreen Design Studio specialises in low energy family home design, one-off houses and small bespoke housing developments. Heather is a firm believer in creating spaces based around users which are filled with natural light, create framed views and link inside with outside to unlock the potential in every property and give users an uplifting ‘wow’ moment every time they come home. 

Collaborative, Supportive and Passionate

Evergreen Design Studio believe in the power of collaboration to create exceptional architecture. We work closely with you to develop a design that creates an inspirational space that works for you and minimises environmental impact as well as energy bills. We spend time to understand your vision and goals and develop a design that reflects these but exceeds your expectations.

Iterative, Warm and Responsive

Evergreen Design Studio take an iterative approach in my work to ensure the final design aligns with your unique project requirements and architectural vision. We’ll work together to refine and fine-tune your building design, leaving no detail overlooked. 

In design, communication is key, we will always respond promptly to your queries and observations to maintain project momentum.

Experienced, Connected and Knowledgeable

Heather leads the design and management of all projects, with the support of chosen consultants and collaborators when required. We can offer the full design service covering all RIBA Stages of Work from initial concept design through to contract administration on site. Evergreen Design Studio has contacts throughout the design and construction industry and as such we are well versed and happy to collaborate with other design and construction professionals. 

Heather has spoken at a number of events and appeared in several publications discussing sustainability. She has been a guest speaker at two Sustainable St Albans events, appeared on BBC Newsnight discussing Passivhaus and how you can be more sustainable at home and appeared in The Times.

With an expertise in sustainable and low energy design, we can also work as an extension to a main project team to make sure that design aesthetics are celebrated whilst making the building as energy efficient as possible in a consultant capacity. 

Family Focussed 

Heather lives in North Hertfordshire and works flexibly to fit in around her husband Olli, dog Winston and soon-to-be growing family so she understands that communication and meetings don’t always fall easily into traditional office hours. This flexibility affords the opportunity for client discussions to occur outside normal office hours which can often be beneficial all round so please don’t be shy in asking for meetings to happen on a schedule that suits you! It also means you may get emails from her at odd times, but be assured she will get back to you promptly!

Heather has worked within the architectural design industry since the age of 16. With over 15 years in the industry, Heather has gained a wide scope of experience working in several practices across the country on projects ranging from small extensions to Olympic sports venues.

2025 Heather started Evergreen Design Studio with a drive to work more collaboratively with clients and help them create homes that work around them and provide healthy, sustainable living environments

2024 Heather was named one of the RIBA Journal’s Rising Stars of 2024 in recognition of her work in the Passivhaus and sustainable architecture field. She was also project lead and Passivhaus Designer on the first retrofit Passivhaus Plus project to be certified in the UK

2023 Heather’s first EnerPHit Plus project, and only the third one to be certified in the UK, was named a Finalist in the Passivhaus Trust Awards and was the People’s Choice Runner Up

2022 The same project won a Commendation in the Sustainability Category at the HAA Architecture Awards

2021  Fully qualified RIBA and ARB Architect with Postgraduate Diploma in Professional Practice Architecture from Kingston University - ARB/RIBA Part III. Case study project was the aforementioned EnerPHit Plus project

2018  Professional Diploma in Architecture with Advanced Environmental and Energy Studies at Centre for Alternative Technology, Machynlleth, Wales - ARB Part II

2015  BSc(Hons) in Architecture at University of Bath - ARB/RIBA Part I

2008 Heather started her first job in the industry

Proven Track Record

Heather is proud of her track record and client relationships formed during the successful completion of architectural designs and homes that her clients love.

Please refer to the Testimonials for a greater insight.