Our committee

Find out more about us

The short biographies of our committee members illustrate the diversity of our team. We represent many of the disciplines associated with the conservation of Historic Interiors. 

If you would be interested in joining our committee please get in touch at one of our events or through the contact details listed under Charlotte Owen or Sandra Howe.


Christine Sitwell ACR

Chair, Icon Historic Interiors Group

Christine trained as a paintings conservator at Winterthur Museum, University of Delaware before embarking on an internship at the Tate Gallery, London.

She joined the National Trust in 1990 as a paintings conservation advisor responsible for managing and organising the conservation of the Trusts' collection of paintings and also advising on historic interiors with regard to paint analysis and conservation of painted surfaces.

Lisa Oestreicher

Secretary, Icon Historic Interiors Group

Lisa came over from her native Canada in the 1980's to finish her studies at the Bartlett School of Architecture and the Architectural Association. After several years working at Westminster City Council as a conservation officer Lisa went back to specialise in architectural paint research as part of the Royal College of Art/Victoria & Albert Museum conservation training programme.

Lisa has been involved in the Historic Interiors Group since its inception.

Helen Hughes ACR FIIC

Committee Member, Icon Historic Interiors Group

Helen is one of the founder members of the Historic Interiors Group. Since 2009 she has worked as a freelance Architectural Paint Researcher. Before this she headed the Historic Interiors Research and Conservation Unit of English Heritage for 25 years.

Helen holds a degree in the History of Art & Architecture and Easel Painting Conservation and is an ICON Accredited Conservator-Restorer and a Fellow of the International Institute of Conservation. She has worked on a wide range of historic interiors projects and also teaches conservation history and theory at several universities in the UK and abroad.

Charlotte Owen

Social Media Officer, Icon Historic Interiors Group

Charlotte trained as an objects conservator at Lincoln University before joining the National Trust as a conservation assistant and project conservator (2009-2013), project conservator for English Heritage (2013-2014) and Cambridge University Museums (2014-2015).

After a short stint as a freelance project conservator Charlotte joined Hirst Conservation as an architectural paint researcher, she has been a committee member since 2015 and manages web content.

[email protected]

Alice Law

Social Media Officer

Alice is the 2023-4 Icon Bute Intern in Collections Care and Historic Interiors with the National Trust for Scotland. She holds a degree in History of Art; and trained in Object Conservation at Cardiff University, completing an MSc in Conservation Practice in 2022.

She has experience volunteering with organisations including the National Trust, the Museum of Welsh Cricket and the National Army Museum and is currently learning about the care of collections in the unique environments of historic buildings.

Sandra Howe ACR

Committee member, Icon Historic Interiors Group

Sandra trained as an objects conservator at DeMontfort University and has been working for the National Trust since 2002 as a regional conservator, currently based in York. Advising on preventive conservation, commissioning remedial treatment of objects and promoting the balance of access and conservation in historic houses.

Sandra joined the Historic Interiors committee in 2012.

[email protected]

Ayaka Takaki

Treasurer, Icon Historic Interiors Group

Ayaka is an Architect, accredited with Specialist Conservation Architect (SCA) and Architect Accredited in Building Conservation (AABC), and specialises in the repair and conservation of historic and listed buildings. She is currently working for Donald Insall Associates as an Associate.

She understands the intricacy of working in historic buildings and has experience of managing the logistics and expectations of end users and stakeholders, from project initiation to post-completion. Ayaka joined the committee in 2018.

May Berkouwer ACR

Committee Member, Icon Historic Interiors Group

May trained as a textile conservator in Amsterdam (1980-1984) before working at the National Trust's Levy Textile Workroom and Ksynia Marko's Textile Conservation Studio in London. May has been independent since 1992 setting up her own studio in Suffolk in 1996.

May and her team work on a wide range of interior and ecclesiastical textiles as well as tapestries, embroideries, flags, banners and costume. May was accredited in 1999 and has been an assessor for Icon Accreditation since 1991; she joined the Historic Interiors Committee in 2012 

Heather Tetley ACR

Committee Member, Icon Historic Interiors Group

Heather worked at The Carpet Conservation Workshop, Salisbury (1988-1996) undertaking conservation of historic carpets for historic houses, Royal collection and private clients before opening The Tetley Workshop, Devon in 1996.

The Tetley Workshop specialises in all aspects of the conservation of historic carpets in historic houses and private collections; including a Royal Warrant Holder to HM The Queen for Conservation of Carpets.

Saskia Huning

Committee member

Saskia Huning is an artist and specialist decorator. She works on the restoration and recreation of decorative schemes and murals, both modern and historic.

Saskia joined the family business, Huning Decorations twenty-three years ago. Since then she has developed a great interest in traditional paints and different methods of applying paint.

Much of her work involves recreating parts of or whole historic schemes from many different periods, using both modern and traditional techniques. Saskia often works alongside conservators in her work.

Lesley Scott ACR

Committee member

Lesley is an Accredited conservator in object conservation and gilding with extensive experience of the heritage sector; having worked for museum services, museums, charitable trusts, self-employed and more recently at Museums Galleries Scotland.  Currently a Regional Conservator for the National Trust for Scotland Lesley leads on the preventive care of property interiors and collection care for the historic houses in the portfolio of the Edinburgh & East region.