DONALD INSALL ASSOCIATES CHARTERED ARCHITECTS HISTORIC BUILDING & PLANNING CONSULTANTS 19 WEST EATON PLACE LONDON SW1X 8LT TEL 020-7245 9888 FAX 020-7235 4370 E-mail [email protected] Website www.insall-lon.co.uk STJ.3/FM/mlb.019 Luciana Grave Conservation Officer London Borough of Islington 222 Upper Street London N1 1XR By e-mail: [email protected] 30 March 2009 Dear Luciana MUSEUM OF THE ORDER OF ST JOHN, ST JOHN’S GATE: LINK GALLERY ROOF Following our recent conversation, we have revised our Link Gallery Roof designs shown on the attached drawings 1107C, 1108C and 4108C. The principal changes are that i) the gantry has been removed; ii) the roof is now a single pitch sloping downwards to a gutter at the north end; iii) we have allowed for an air vent in the recess by the south end of the space. The following additional points may be of interest: a) The glass as shown will need to be cleaned from the second floor windows along the eastern side of the space (windows visible in drawing 1108C). The electrochromatic glass panels cannot be walked on because any flexing of them will cause the electrochromatic layer to fail, according to manufacturer’s advice. If the roof is to be walked on, we would have to provide an additional outer layer of glass which be thick and consequently heavy to support the weight of service personnel walking on it. A more robust sand visually intrusive supporting structure will also be necessary than the widely spaced laminated glass beams and the glazing bars (detail A, drawing 4108C), which we have shown, the latter of which are necessary principally to conceal the edges of the double glazed units and the wiring which energises the electrochromatic layer in the inner leaf. Directors Nicholas V Thompson, BArch (Hons), RIBA (Chairman) Alan Frost, LVO, AA Dipl, RIBA, DCHM, MaPS (Deputy Chairman) Donald W Insall, CBE, FSA, RWA, FRIBA, FRTPI, SP Dipl (Hons) Iona Gibson, Dipl Arch, RIBA Jonathon Carey, Dipl Arch, RIBA Mark Wilkinson, BA (Hons), DipArch, RIBA Michael Shippobottom, MA, BArch, RIBA Simon Charrington, FCA, ATII (Company Secretary) Senior Associates Robert Dunton, BArch, BSc, RIBA Tony Dyson, Dipl Arch, RIBA Anthony Close-Smith, BA (Hons), BArch (Hons) Tony Barton, BA (Hons), DipArch, RIBA Peter Riddington, BSc (Hons), BArch (Hons), RIBA Peter Carey, BA (Arch), DipArch, RIBA John Dangerfield, Dipl Arch, RIBA Matthew Seaborn, BA (Hons), Dip Arch, RIBA, FRSA Associates Maureen O’Conner, BA (Hons), BArch (Hons), RIBA, MaPS Robert Brown, BArch (Hons) Robin Dhar, BA (Hons), Dip Arch, RIBA, MaPS Helen Hutchinson, BA, BArch, MA, RIBA, IHBC Robert Fraser, Dip Arch, RIBA IHBC Geoffrey Broster, Dip BS, FRICS, MaPS Peter Cooke, BA (Hons), DipArch, RIBA Francis Maude, MA, Dipl Arch, RIBA Gillian Scanlon, BA (Hons), BArch, RIBA Toby Sargeant (Accounts) Consultants Peter Locke, FSA, RIBA (Cambridge) Carol Thickins, BA (Arch), MA Arch, RIBA Christopher Martindale, FRIBA (Chester) DONALD INSALL ASSOCIATES LTD REGISTERED IN ENGLAND No 1550406 VAT REGD No 240 3358 92 REGISTERED OFFICE 19 WEST EATON PLACE LONDON SW1X 8LT LONDON BATH CAMBRIDGE CANTERBURY CHESTER SHREWSBURY b) Don Bianco has identified the possibility of establishing a temporary manufacturing facility to allow larger panels to be made than SmartGlass’s Dublin works are able to provide. These panels could span the full east-west width of the gallery. No costs have yet been worked out for this. However, from a technical point of view, our preference is to have a grid of SmartGlass panels (see glazing layout on drawing 4108C) as this allows us to switch them to clear or dark blue opaque depending on which side of the roof is in shade or direct sun, so maximising the amount of the roof which can left clear, giving the views upwards we have been striving to provide. There is also the secondary issue of wishing to minimise the number of joints across the line of water flow, in which water may become trapped and leak into the building, or upset the electrical energising circuits. Yours sincerely Francis Maude for and on behalf of Donald Insall Associates Ltd cc. (by email) Dorian Crone Don Bianco Stephen Greenberg Pamela Willis Mike Cook Nick Gold .