Long Sutton Studio, Hampshirestructureworkshop.co.uk/site/wp-content/uploads/2018/01/...The glulam...
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1 Case Study © Exova (UK) Ltd. 2016 Project information Completion date: May 2013 Building type: Studio, workshop Location: Hampshire Client: Tom Lloyd Architect: Cassion Castle Architects with Tom Lloyd Structural Engineer: Structure Workshop Contractor: Cassion Castle Architects Timber supplier: Honeysuckle Bottom Sawmill Glulam structure: Kingston Craftsmen Timber elements: Glulam portal frame, cladding, framing and sills, sheathing to roof Timber species: English oak, redwood Introduction Set at the end of a long rural track in Hampshire, Long Sutton Studio is a building which celebrates timber in its many forms: softwood and hardwood, laminated, planed and rough sawn. Timber is the predominant material, used for both structure and cladding, and its different forms give texture, identity and character to the building. Although Long Sutton Studio might appear to be a very traditional timber building at first glance, a closer look reveals a contemporary approach to structure, form and detailing. The client, Tom Lloyd is a product designer and the site is in the grounds of his home, a former farmhouse in Hampshire. He wanted a building that could fulfill a series of basic functions; studio, workshop, garage or storeroom. It was also an opportunity to combine architecture and timber craftsmanship to create a simple yet beautiful studio that would enhance the rural setting of his house. Tom obtained outline planning permission and was closely involved in all aspects of the design with the architect Cassion Castle Architects and the structural engineer Structure Workshop. Long Sutton Studio replaces a concrete garage and timber shed, both of which were in a poor state of repair. A key objective was to replace these with a single building that was more sympathetic to the main house in its design and choice of materials. The new studio is deliberately understated; its traditional pitched roof form suggests that it might have stood there for many years, blending inconspicuously among nearby vernacular buildings, but close inspection reveals the modern detailing which gives it a subtle and contemporary identity. Externally, the studio is an assembly of traditional materials – green oak, red brick, reclaimed roof tiles – reflecting those used on the main house. In contrast, the interior of the studio is a lofty single-volume space with all the timber elements clearly expressed and visible. The primary structure is a series of six portal frames, of glulam members connected by exposed galvanised steel plates and fixings. With the use of stiff joints, the glulam frames create an interior which is open up to the ridge, crossed only by delicate steel tension cables. Spaces created within the depth of the walls are used as workspaces, shelving and storage. Objects placed here, such as a log pile or piece of wooden furniture, take on sculptural characteristics themselves and extend the celebratory use of timber. Long Sutton Studio is completely accessible to all building users. Because it is illuminated almost entirely by natural light and has no heating, its carbon footprint is negligible. Long Sutton Studio, Hampshire Studio, workshop
Transcript of Long Sutton Studio, Hampshirestructureworkshop.co.uk/site/wp-content/uploads/2018/01/...The glulam...
1Case Study© Exova (UK) Ltd. 2016
Project informationCompletion date: May 2013
Building type: Studio, workshop
Location: Hampshire
Client: Tom Lloyd
Architect: Cassion Castle Architects with Tom Lloyd
Structural Engineer: Structure Workshop
Contractor: Cassion Castle Architects
Timber supplier: Honeysuckle Bottom Sawmill
Glulam structure: Kingston Craftsmen
Timber elements: Glulam portal frame, cladding, framing and sills, sheathing to roof
Timber species: English oak, redwood
IntroductionSet at the end of a long rural track in Hampshire, Long Sutton Studio is a building which celebrates timber in its many forms: softwood and hardwood, laminated, planed and rough sawn. Timber is the predominant material, used for both structure and cladding, and its different forms give texture, identity and character to the building. Although Long Sutton Studio might appear to be a very traditional timber building at first glance, a closer look reveals a contemporary approach to structure, form and detailing.
The client, Tom Lloyd is a product designer and the site is in the grounds of his home, a former farmhouse in Hampshire. He wanted a building that could fulfill a series of basic functions; studio, workshop, garage or storeroom. It was also an opportunity to combine architecture and timber craftsmanship to create a simple yet beautiful studio that would enhance the rural setting of his house. Tom obtained outline planning permission and was closely involved in all aspects of the design with the architect Cassion Castle Architects and the structural engineer Structure Workshop.
Long Sutton Studio replaces a concrete garage and timber shed, both of which were in a poor state of repair. A key objective was to replace these with a single building that was more sympathetic to the main house
in its design and choice of materials. The new studio is deliberately understated; its traditional pitched roof form suggests that it might have stood there for many years, blending inconspicuously among nearby vernacular buildings, but close inspection reveals the modern detailing which gives it a subtle and contemporary identity.
Externally, the studio is an assembly of traditional materials – green oak, red brick, reclaimed roof tiles – reflecting those used on the main house. In contrast, the interior of the studio is a lofty single-volume space with all the timber elements clearly expressed and visible. The primary structure is a series of six portal frames, of glulam members connected by exposed galvanised steel plates and fixings. With the use of stiff joints, the glulam frames create an interior which is open up to the ridge, crossed only by delicate steel tension cables. Spaces created within the depth of the walls are used as workspaces, shelving and storage. Objects placed here, such as a log pile or piece of wooden furniture, take on sculptural characteristics themselves and extend the celebratory use of timber.
Long Sutton Studio is completely accessible to all building users. Because it is illuminated almost entirely by natural light and has no heating, its carbon footprint is negligible.
Long Sutton Studio, HampshireStudio, workshop
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Long Sutton Studio, HampshireStudio, workshop
Case Study© Exova (UK) Ltd. 2016
Key long section through studio
Key
1 glulam portal frame
2 175 x 75mm glulam purlins
3 conservation rooflight
4 75 x 50mm rafters at 400mm centres
5 ledged and braced timber door on 180 degree hinges
6 175 x 75mm glulam sheeting rails
7 75 x 50mm wall studs at 400mm centres
8 green oak board-on-board cladding on counter-battens
9 red brick plinth
10 reinforced concrete slab
Key plan of studio
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Long Sutton Studio, HampshireStudio, workshop
Case Study© Exova (UK) Ltd. 2016
Cross section through studio
Key
1 270 x 90mm glulam portal frame
2 175 x 75mm glulam purlins
3 gable window
4 75 x 50mm rafters at 400mm centres
5 175 x 75mm glulam sheeting rails
6 75 x 50mm wall studs at 400mm centres
7 green oak board-on-board cladding on counter-battens
8 red brick plinth
9 reinforced concrete slab
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Long Sutton Studio, HampshireStudio, workshop
Case Study© Exova (UK) Ltd. 2016
Externally the studio is an assembly of traditional materials - green oak, brick and reclaimed roof tiles.
The walls are clad with vertical boards of rough sawn green oak weatherboarding set on a red brick plinth. The pitched roof is sheathed in plywood and laid with reclaimed tiles. Natural light is admitted through roof lights set in the slope of the roof, avoiding the need for windows in the main elevations which would have interrupted the strong rhythm of the weatherboarding. Two sets of large oak-clad double doors open up to admit further light when weather permits.
The cladding is board-on-board green oak fixed to chamfered, 50mm deep treated softwood counter battens. The boards are visible from inside the building – there was no requirement for insulation. The oak was sourced from a sawmill not far from the site, where it was sawn to wider 145mm x 22m boards and narrower 60 x 22mm boards, delivered to site green.
Given the risk of movement, cupping and shrinkage of the green oak, the architects consulted TRADA on the application of the cladding. ‘We consulted TRADA on fixing methods, overlap and orientation of the vertical board-on-board cladding. We used the wider board on the inside, heartwood-in, with a 20mm gap between; externally we used the narrower boards, heartwood-out, which covers the gap with a 20mm overlap of the wider board either side. TRADA also gave advice on the number and spacing of the stainless steel fixings, how much movement could be expected in the oak and the likelihood of boards splitting with single or multiple fixings per plank. TRADA’s experience helped us to understand the material characteristics to a greater degree, and confidently specify the correct fixing methods for the application’.
The studio is clad with rough-sawn green oak, laid vertically board-on-board.
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Long Sutton Studio, HampshireStudio, workshop
Case Study© Exova (UK) Ltd. 2016
Detail cross section through roof and wallKey
1 reclaimed clay roof tiles on treated sw battens and ply sheathing
2 aluminium gutter
3 270 x 90mm glulam portal frame with galv steel tie-rod
4 175 x 75mm glulam purlins
5 flitched steel plate as glulam frame connection
6 75 x 50mm C24 rafters at 400mm centres
7 175 x 75mm glulam sheeting rails
8 75 x 50mm PSE redwood wall studs at 400mm centres
9 galv steel tie-rod
10 145mm x 22m and 60 x 22mm green oak board-on-board cladding on counter-battens
11 red brick plinth
12 trapped gulley
13 reinforced concrete slab on dpm
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Long Sutton Studio, HampshireStudio, workshop
Case Study© Exova (UK) Ltd. 2016
The glulam portal frame members are bolted together with flitched steel plates.
The structurePeter Laidler, Director, Structure Workshop describes his approach to the structure.
‘The design of the building resulted from an equitable collaboration between client, architect and engineer, all of whom had worked together previously.
From the outset the client was clear in his brief for an essentially vernacular building, carefully detailed. The location was agreed on site and as structural engineers we proposed both plan grid and framing arrangement. The architect’s input subsequently followed and owing to also being the contractor, allowed for the integrated detailing and construction of the building. This resulted in a clearly expressed building that sits calmly in its setting.
Numerous options were considered for the framing arrangement. Of particular interest technically was the positioning of pinned connections to allow easy analysis and simple construction. Conceptually an arch, or in this case a frame, can contain up to three pins i.e. joints that permit rotation, and remain stable. More than three pins and the arch becomes a mechanism and cannot be ratified. Fixed joints attract moment and require more fasteners. It was therefore decided to locate pinned joints at the eaves and ridge to minimise the visual clutter in these prominent positions, and to fix the column bases which are less noticeable. To reduce the glulam section sizes a tied collar was introduced and by using flitch plates let into the solid sections, steel dowels were designed in place of bolts to further refine the connections. In the event bolts were used instead of dowels to save on cost.
The secondary framing is non-standard in that there is no ridge board or wall plate. Instead, offset purlins are fixed to the principle rafters and the columns, common studs and rafters are half lapped with one another and bolted together at the ridge and the eaves.
Longitudinal stability is provided by diagonal bracing rods which run around the walls and roof at each end resulting in a symmetrical structure in plan, section and elevation.
These subtle departures from standard detailing combine to contribute to the simple but carefully detailed structural form’.
Spaces created within the structure are used for storage and workspaces.
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Long Sutton Studio, HampshireStudio, workshop
Case Study© Exova (UK) Ltd. 2016
All the timber elements in the single-volume space are visible and clearly expressed.
Awards: RIBA Award 2014 shortlist
Blueprint Award 2014
Surface Design Award 2015
The 270 x 90mm gulam frames are set at three metre centres and support a series of smaller components, layered over them in a clear hierarchy. Along the pitched roof, two large 175 x 75mm glulam purlins run behind the glualm portals, each notched in and connected to them with a bolted steel flitch plate. A series of 75 x 50mm C24 rafters are screwed to the purlins at 400mm centres. There are no eaves beams or ridge beams;
instead the rafters are half lapped at the ridge and bolted together, while at the eaves the rafters are half lapped to the wall studs.
Along the walls, two large 175 x 75mm glulam sheeting rails run behind the glulam columns and are notched and connected to them with bolted steel flitch plates. The 75 x 50mm wall studs are also exposed; they run at 400mm centres and are screwed to the sheeting rails.
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Long Sutton Studio, HampshireStudio, workshop
Case Study© Exova (UK) Ltd. 2016
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Photography: © Cassion Castle ArchitectsDrawings: © Killian O’Sullivan
About TRADAThe Timber Research and Development Association (TRADA) is an internationally recognised centre of excellence on the specification and use of timber and wood products.
TRADA is a company limited by guarantee and not-for-profit membership-based organisation. TRADA’s origins go back over 80 years and its name is synonymous with independence and authority. Its position in the industry is unique with a diverse membership encompassing companies and individuals from around the world and across the entire wood supply chain, from producers, merchants and manufacturers, to architects, engineers and end users.
Our aimTo provide members with the highest quality information on timber and wood products to enable them to maximise the benefits that timber can provide.
What we doWe seek to achieve this aim through active and on-going programmes of information and research. Information is provided through our website, an extensive collection of printed materials and our training courses.
TRADAt +44 (0) 1494 569601 f +44 (0) 1494 565487e [email protected] w trada.co.uk
Whilst every effort is made to ensure the accuracy of the advice given, the company cannot accept liability for loss or damage arising from the use of the information supplied.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form, by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner.
Exova BM TRADA Chiltern House Stocking Lane Hughenden Valley High Wycombe Buckinghamshire HP14 4ND UKt +44 (0) 1494 569600 f +44 (0) 1494 565487 e [email protected] w exovabmtrada.com
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